WO1989007199A1

WO1989007199A1 - Pump

Info

Publication number: WO1989007199A1
Application number: PCT/CH1989/000016
Authority: WO
Inventors: Rudolf A. Hatschek; Frédéric Neftel
Original assignee: Debiopharm Sa
Priority date: 1988-02-05
Filing date: 1989-01-27
Publication date: 1989-08-10
Also published as: EP0355150A1; AU2942089A

Abstract

A pump comprises a pump body (5001) which forms a delivery passage (5049) during operation, into each end of which a fluid connection (5071, 5073) opens. The delivery passage (5049) is delimited, on at least one side, by a delivery surface (5037) which can be bent, in particular curved for example in certain places to form domes, by a transducer (5005). An electronic device connected to the electrodes of the transducer (5005) deforms the latter during operation by supplying electrical excitation signals in such a way that the fluid being pumped is conveyed peristaltically through the delivery passage (5049). When the pump is at rest, the delivery surface (5037) and the surface (5035) which faces and delimits delivery passage (5049) are adjacent and parallel. The delivery passage (5049) contains no non-return or other type of valves or dead spaces, and permits uniform delivery of fluid and cost-effective manufacture of the pump.

Description

pump

description

Technical field of the invention

The invention relates to a pump according to the preamble of claim 1, namely a pump with two connections, a passage connecting them during operation and transducer means, the passage in cross section on one side through a conveying surface which is bendable at least in places by the transducer means it is limited that a fluid can be conveyed through the passage by bending the conveying surface.

The pump is intended in particular for the continuous or intermittent pumping and metering of relatively small amounts of an at least partially liquid fluid, i.e. a liquid or suspension. For example, for certain medical treatments, it is advantageous to continuously or quasi-continuously deliver a medicament in the form of a liquid or suspension to tissue parts or possibly directly into the bloodstream of a human or animal for an extended period of time, such as for a few days or weeks

Pump body into it, the desired feed rate can be, for example, between 0.1 and 10 mm ³ / min.

With the quasi-continuous, intermittent supply, it can be advantageous, for example, to supply an approximately 10 to 30 second burst of liquid every minute. State of the art

Cell pumps are now known, for example, which have a housing with two connections for supplying and discharging the fluid to be pumped and an eccentrically rotatably mounted rotor which is provided with radially displaceable or bendable vanes. The housing, together with the rotor, delimits a passage for the fluid to be conveyed. The vanes form elevations projecting beyond the bottom of the cells toward a contact surface formed by the housing and, with respect to the direction of movement of the rotor, serve as front and rear end boundaries of fluid-conveying cells moving along the passage. However, such known cell pumps are not suitable for conveying and metering fluid quantities of approximately or less than 10 mm ³ / min and would also be difficult to make sterile and keep sterile. Furthermore, such pumps, as well as the motors required to drive them and the reduction gears, which are also required at least in order to achieve low pumping rates, are relatively large and heavy and also require a relatively large amount of energy during operation, so that a patient connected to such a pump has great freedom of movement impaired and would be forced to guard the bed practically throughout the duration of the drug delivery.

A pump known from DE-A-36 18 107 has a dimensionally stable, generally flat plate with a surface provided with channels. Each channel has three circular extensions, which are connected in pairs by connecting sections. The first and third extensions are each divided into two halves by a crossbar, while the middle extension is completely free. A funding body is at rest with one flat conveying surface on the plate surface provided with the channels and covers the channels so that they each form a conveying passage. The conveying member has a nickel layer on its side facing the plate and a piezoelectric ceramic layer on its side facing away from the plate. This is provided on its side facing away from the nickel layer in the region of each circular widening of the channels with a central electrode and an electrode surrounding it in a ring. When the pump is in operation, the regions of the delivery element which are provided with electrodes and each form a transducer section can be domed in a dome shape. The first and third expansion of a channel, together with the associated converter section, then serves as a valve. The middle extension forms a pump room, the volume of which can be changed between a minimum and a maximum value.

The delivery passage of the pump known from DE-A-36 18 107 thus has a relatively large volume and dead spaces even in the idle state, which is particularly troublesome when relatively small amounts of a fluid are to be pumped, which like many medications are very expensive is. Furthermore, the space requirement of the pump is increased by the connecting sections of a channel that are present between the adjacent extensions. A very significant disadvantage of the known pump is that the cross-sectional changes of each channel along this and in particular the transverse webs in the first and last extension of a channel cause turbulence and greatly increase the flow resistance and thus the given dimensions of the pump and the given dimensions of the Transducer sections affect achievable delivery rates. It also increases the manufacture of a relatively complicated shape channels have the manufacturing cost of the pump. Furthermore, when the pump is operating, the fluid is delivered in a pulsating manner, the closing of the valves causing backflows and increasing the already mentioned formation of turbulence. In the exemplary embodiment of the pump shown in FIGS. 1 to 10 of EP-A-36 18 107, the piezoelectric layer is approximately 0.2 mm and the nickel layer approximately 0.1 mm thick (cf. column 8, lines 41 to 46). The bulging of a transducer section is - starting from its flat rest shape - brought about by the fact that the piezoelectric ceramic layer changes its dimensions relative to the nickel layer connected to it. If one now assumes in a thought experiment that the circular section of the nickel layer belonging to a converter section, which is flat in the idle state, is separated from the rest of the nickel layer and does not expand when it bulges out, its diameter is shown in the plan, that is, in a projection onto that of the converter section in Hibernation spanned level smaller. Since said circular section of the

However, in reality the nickel layer is connected to the remaining part of the nickel layer, bulging of the nickel layer is only possible if it stretches. However, since nickel has a relatively high strength and a large modulus of elasticity, the nickel layer opposes expansion to a large resistance, which hinders the bulging. The bulges of the conveying surface that can be achieved with predetermined transducer section dimensions and with predetermined electrical voltages supplied to the electrodes and the pressure forces that can be transmitted from the latter to the fluid to be conveyed are therefore relatively small, which in turn reduces the amount of fluid that can be conveyed per unit of time and the fluid pressure that can be generated by the pump. Presentation of the invention

The invention is based on the object of creating a drawback of the known pump-eliminating pump, which in particular should also enable very small, for example in the size of 10 mm 3 / min or 1 mm ³ / min or below, delivery rates and to allow a sufficiently precise dosage. Furthermore, the delivery passage of the pump should have as little dead space as possible and enable a fluid to be conveyed through it as turbulently and as uniformly as possible, so that the flow resistance becomes as low as possible. Furthermore, the pump should enable predetermined pump properties - such as the amount of fluid that can be delivered per unit of time and / or the amount that can be generated

Fluid pressure - to be achieved with the smallest possible dimensions of the pump and also require little energy during operation, so that a person or animal can carry the pump with them without significantly impairing their freedom of movement. In addition, the parts of the pump that come into contact with the conveyed fluid should preferably be easily sterilizable and sterile. Furthermore, the pump should advantageously be producible from as few components as possible and at low cost, so that it is economical even when used once.

This object is achieved by a pump, which according to the invention is characterized by the characterizing part of claim 1 and thus characterized in that the passage on its side opposite the conveying surface in cross section through at least anywhere between the mouths of the two connections into the passage in the idle state Conveying area parallel area is limited. Advantageous embodiments of the pump emerge from the dependent claims. The conveying surface and the surface opposite this passage are advantageously formed at least between the mouths of the two connections into the passage by a one-piece, continuous component and each have the shape of a continuous control surface, preferably when the pump is idle. For clarification, it should be noted that in mathematics, a control surface is understood to mean a surface that can be created by moving a straight line in space. The control surface can, for example, be flat or cylindrical or conical.

Brief description of the drawing

The subject of the invention should now be based on the

Drawing illustrated embodiments are explained. In the drawing shows

1 shows a schematic and not to scale section through a pump with a rotor, the one

Conveying element having a conveying surface which is perpendicular to the axis of rotation in the idle state and which forms wave crests projecting parallel to the axis during operation, the wave crests in this figure and also in the following figures showing wave profiles being drawn with a greatly exaggerated height,

2 shows a section through the pump along the line II - II of FIG. 1,

FIG. 3 shows a developed section through part of the pump along the line III-III of FIG. 2,

FIG. 4 shows an exploded oblique view of the parts of the pump body serving to limit the delivery passage of the pump and a section of the oscillating body, 5 shows a developed section corresponding to FIG. 3 through parts of a pump with a larger ratio between the distance between the connections and the wavelength,

6 shows a simplified section through parts of a variant of a pump, the pumping element of which is configured the same or similar to that of the pump shown in FIGS. 1 to 4, but the seal delimiting the pumping passage is designed differently,

FIG. 7 shows a section through the pump shown in FIG. 6 along the line VII-VII of FIG. 6,

8 shows a schematic section through a pump, the rotor of which has a conveying element with a conveying surface which is parallel to the axis of rotation in the idle state and which forms radially protruding wave crests during operation,

9 shows a section through the pump according to FIG. 8 along line IX-IX of FIG. 8,

10 shows an oblique view of the sealing body and the contact body of the pump according to FIGS. 8 and 9,

FIG. 11 shows a section through parts of a pump, the conveying member of which is designed to be the same or similar to the pump shown in FIGS. 8 to 10, but the conveying passage is limited differently,

FIG. 13 shows a schematic representation of a pump with a conveying surface which is conical in the idle state, the pump body being shown in section and the rotor in view and with the conveying member separated from the pump body, and FIG. 14 shows a section through a plate-shaped one Conveyor element, the conveying surface of which forms wave crests projecting in the direction parallel to the axis of rotation,

FIG. 15 shows a section through a conveyor element with a rib projecting in the axial direction and forming the conveyor surface,

FIG. 16 shows a section through an annular conveyor element, the conveyor surface of which has two sections forming an angle in cross section, the angle apex projecting parallel to the axis of rotation,

FIG. 17 shows a section through an annular conveyor element, the outer surface of which is parallel to the axis of rotation and serves as the conveyor surface,

18 shows a section through an annular conveyor element, the conveyor surface of which consists of two sections which in cross section form an angle with a vertex projecting away from the axis of rotation,

FIG. 19 shows a section through an annular conveying element, the inner surface of which is parallel to the axis of rotation and serves as the conveying surface,

FIG. 20 shows a section through an annular conveying member with an inner surface which serves as a conveying surface and is conical in the idle state,

FIG. 21 shows a schematic section through a pump with a conveying passage extending approximately around the entire circumference of the rotor, the conveying surface forming a shaft with two wave crests,

22 shows a schematic section through a Pump, which is similar to the pump in FIG. 21, but with the delivery surface forming a shaft with three wave crests,

FIG. 23 shows a section through a pump for simultaneous, separate pumping of two fluids,

FIG. 24 shows a schematic section, not to scale, through a pump with an elongated contact member and an elongated conveying member having piezoelectric transducer means, the conveying surface of which facing the contact member forms a progressive shaft during operation,

FIG. 25 shows a section through the pump according to FIG. 24 along the line XXV - XXV of this figure,

FIG. 26 shows an oblique view of a section of the piezoelectric element of the pump shown in FIGS. 24 and 25 to illustrate shear, on a larger scale,

27 shows a plan view of the longitudinal side of two sections of the piezoelectric element of the pump shown in FIGS. 24 and 25 on a larger scale,

FIG. 28 shows a diagram to illustrate the change over time in the shape of the conveying surface due to shear of the piezoelectric element,

FIG. 29 shows an electrical block diagram of the pump shown in FIGS. 24 and 25,

Figure 30 is a diagram showing the time the course of the voltages supplied to the electrodes of the piezoelectric transducer means of the pump according to FIGS. 24 and 25,

FIG. 31 shows a section of a piezoelectric element for generating changes in length,

FIG. 32 shows a region of a conveyor element with a piezoelectric element which, according to FIG. 31, has sections which can be changed in length and is connected to a non-piezoelectric flexible body to form a flexible transducer,

FIG. 33 is a diagram showing the change in the shape of the conveying surface over time due to changes in the length of sections of the piezoelectric element,

FIG. 34 shows a schematic section through an area of a conveyor element which is in the idle state and whose transducer means have two piezoelectric elements,

FIG. 35 is a view of two superimposed sections of the piezoelectric elements of the transducer means shown in FIG. 34 when their lengths are changed,

FIG. 36 shows a view of an area of the conveyor element according to FIG. 34, but in a bent state,

FIG. 37 is a plan view of the conveying surface of an elongated conveying element, the converter means of which have thermoelectric elements,

FIG. 38 shows a plan view of one end of the in FIG. 37 shows the conveying body,

FIG. 39 shows an oblique view of a region of the conveyor element shown in FIGS. 37 and 38, only a single thermoelectric element being shown,

FIG. 40 is a plan view of a ring-shaped conveying element with a conveying surface which, when at rest, lies in a plane perpendicular to the ring axis and forms an abruptly advancing shaft during operation,

FIG. 41 shows a plan view of an annular conveying member with a circularly cylindrical conveying surface in the idle state, forming a progressive shaft during operation,

FIG. 42 shows a schematic longitudinal section through a pump with two elongate conveying elements, the mutually facing conveying surfaces of which form advancing waves during operation,

FIG. 43 shows a cross section through the pump shown in FIG. 42,

44 shows an oblique view of the two delivery elements of the pump according to FIGS. 42 and 43,

45 shows a schematic longitudinal section through part of another variant of a pump with two elongate conveying elements, the mutually facing conveying surfaces of which form advancing waves during operation,

FIG. 46 shows a schematic cross section through the pump shown in FIG. 45, FIG. 47 shows a plan view of the side of the delivery elements of the pump according to FIGS. 45 and 46 at the top in FIG. 45, on a smaller scale,

48 shows a plan view, not to scale, of the longitudinal sides of the two delivery elements of the pump according to FIGS. 45 to 47 with a representation of the polarizations of the piezoelectric elements,

FIG. 49 shows a diagram of the time profile of the electrical excitation voltages supplied to the electrodes of the piezoelectric transducer means of the pump according to FIGS. 45 to 48,

50 shows a schematic and in particular not to scale section through a pump along its longitudinal center line, the pump having a fixed contact element and a transducer with four transducer sections that can be arched by different expansions of piezoelectric elements, but are drawn in the plane retirement state,

FIG. 51 shows a top view of the pump shown in FIG. 50, the top electrode and the top piezoelectric element of the transducer having been omitted,

52 shows a schematic cross section, at right angles to the longitudinal direction of the piezoelectric transducer, through the latter, namely through its transducer section, which is located closest to the left end in FIGS.

53 shows a cross section corresponding to FIG. 52 of the piezoelectric transducer, but with a curved transducer section, FIGS. 54 to 58 of FIG. 50 correspond to, but more schematized and simplified, longitudinal sections to illustrate the conveyance of fluid by bulges of the different converter sections that follow one another in time,

FIG. 59 shows a diagram to illustrate the electrical signals supplied to the electrodes of the converter,

60 shows a highly schematic representation of another possibility for conveying fluid by bulging the transducer shown in FIGS. 50 to 53,

61 shows a representation corresponding to FIG. 60 of yet another variant for conveying fluid by bulging the transducer according to FIGS. 50 to 53,

FIG. 62 shows a schematic longitudinal section through a pump which has two conveying elements connected to one another, each with a piezoelectric transducer drawn in the retired state,

FIG. 63 shows an even more schematic and simplified longitudinal section through the pump shown in FIG. 62, the pairs of transducer sections that are most distant from one another being curved,

64 shows a schematic longitudinal section through part of a piezoelectric transducer with transducer sections that are in the retired state and can be curved by shear, FIG. FIG. 65 shows a top view of the upper side of the converter part shown in FIG. 64,

66 shows a longitudinal section through the transducer part shown in FIG. 64, but with a transducer section drawn in the curved state,

FIG. 67 is a plan view of a piezoelectric element with electrodes, the mutually facing edge sections of which are curved concavely,

FIG. 68 shows a schematic longitudinal section through a pump with a piezoelectric film extending over the entire conveying passage and attached to it, each associated with an archable transducer section, piezoelectric bimorph transducer devices,

69 shows a plan view of the side of the piezoelectric film of the pump according to FIG. 68 facing away from the delivery passage and provided with electrodes, the piezoelectric elements of the bimorph transducer devices having been omitted,

FIG. 70 shows a longitudinal section through a pump, the delivery surface of which is formed by an elastically stretchable film,

FIG. 71 shows a longitudinal section through part of a pump, the transducer of which has two piezoelectric elements which have a region which can be stretched for bulging and a region which can be contracted during bulging for each bulging transducer section,

FIG. 72 is a plan view of the side of the piezoelectric element of the pump which is closer to the conveying passage and is provided with electrodes and is provided with electrodes, as shown in FIG. 71 and FIG. 73 shows a highly schematic view of a pump with more than two fluid connections, the bulging transducer sections located in the crack shown in the inner region of the pump each being surrounded by three transducer sections adjoining them and distributed around them.

Preferred embodiments of the invention

The pump shown in FIGS. 1 and 2 has a pump body 1 with a stator 2 and a rotor 3 rotatable about an axis of rotation 5. The stator 2 has a dimensionally stable ring 11 which, on its end face located in FIG. 1 and facing the main part of the rotor 3, has a flat, radial surface 11a perpendicular to the axis of rotation 5. In a sector of the end face having the surface 11a there is a depression 11b, namely a groove, which runs along a part of an arc forming a circle coaxial with the axis of rotation 5 and has, for example, a rectangular cross-sectional shape. The radially measured width of the recess 11b is at least 50% and, for example, at least 70% of the radial width of the ring 11. In the recess 11b, a one-piece, shell and / or trough-shaped sealing body 13 is used, which faces away from the base of the recess 11b Side in turn has a recess 13a, namely an arcuate groove. The depression 13a has, for example, a base area adjoined by side faces which are inclined away from one another in cross section, so that the depression in the cross section is at least substantially trapezoidal and widens towards its mouth. In the recess 13a of the sealing body 13, a dimensionally stable contact member 15 is inserted, which corresponds to the cross-sectional shape of the connector Recess 13a is at least substantially trapezoidal in cross-section, protrudes a little in the direction parallel to the axis of rotation 5 from the recess 11b of the ring 11 and there has a flat contact surface 15a, which is radial to the axis of rotation 5 and rectangular. The edge sections of the sealing body which surround the contact surface 15a in a continuous manner and thus in a ring-like manner and at least when the rotor 3 is separated from the stator 2 at all edges of the contact surface 15a serve as four seals 13b, 13c, 13d, 13e. The stator 2 is provided with two fluid connections 17, 19 which have a passage, one of which opens into the contact area 15a near the seal 13d and the other near the seal 13e. The two connections are connected to the contact element 15 in a fluid-tight manner and can be formed, for example, by connecting pieces molded onto this or by connecting pieces or hoses consisting of separate parts. The sealing body 13, the contact member 15 and the connections 17, 19 are preferably held in the ring 11 in such a way that they do not fall out of the recess 11b even when the rotor is separated from the stator, and for this purpose can be sealed and non-detachably connected to the ring, for example by adhesive connections 11 or be connected to each other. On the surface 11a or, more precisely, on the sector of this surface adjoining the two ends of the recess 11b, a contact layer 21 is applied, the side of which facing away from the ring 11 forms a flat contact surface 21a perpendicular to the axis of rotation 5.

The bearing means used to support the rotor 3 have a bearing 25 with an outer bearing ring fastened in the opening of the ring 11, for example rolling elements consisting of balls, and an inner bearing ring rotatable with respect to the stator. The rotor 3 has one in the inner bearing ring of the bearing 25 axially displaceably held shaft 31, which is provided at its end in FIG. 1 above the bearing 25 with a thread 31a and is rigidly connected at its other end to a dimensionally stable, disk-shaped carrier 33. On the side of the carrier 33 facing the stator 2, a conveyor element, designated as a whole by 41, is attached via an annular, deformable support and / or support body 35, which is used for vibration decoupling and damping. This has transducer means with a schematically illustrated, piezoelectric transducer 43 for converting electrical excitation voltages supplied to it into forces and / or deformations and / or movements, and an elastically deformable, oscillatable vibrating body 45. On its end face facing the stator 2, the latter has a conveying surface 45a that is flat in the idle state, radial and perpendicular to the axis of rotation 5. A nut 51 is screwed onto the thread 31a and a spring 55, namely a plate spring, against the inner one via a washer 53

Presses bearing ring of the bearing 25 and thereby acts on the conveying member 41 of the rotor 3 with a force directed against the ring 11 of the stator 2, so that its conveying surface 45a is pressed against the lower end face of the stator 2. An electronic device 61 and a battery 63 are also attached to the carrier 33, for example on its end face facing away from the conveying member 41. The electronic device 61 is, for example, electrically connected to the piezoelectric transducer 43 via the electrically conductive carrier 33 and / or at least one electrical conductor 65 penetrating a hole thereof, and likewise via the carrier 33 and / or at least one electrical conductor 67 to the battery 63 connected. The pump can also have a housing (not shown) which is fixedly connected to the stator 2 and / or partially formed by it and delimits the rotor 3 from the surroundings. If the pump is intended for supplying a medicament consisting of a liquid or suspension into a body tissue of a living human or animal, the fluid connection 17 serving as the fluid inlet can be provided with a reservoir containing the medicament and held on the stator 2 and not shown the fluid connection 19 serving as the fluid outlet can be connected to the relevant body tissue via a cannula. The stator 2 and / or the possibly existing housing of the pump can be releasably attached to the outside of the body of the person or animal in question or possibly even inserted into the inside of this body.

As already mentioned, the ring 11 and the carrier 33 and, of course, the shaft 31 should consist of a dimensionally stable material, for example a metallic material or a dimensionally stable plastic. The

Contact member 15 and the contact layer 21 should also be reasonably stable, rigid and hard. So that the contact points at which the conveying surface 45a and the contact surface 15a touch each other during the operation of the pump, which will be described in more detail below, are at least somewhat fluid-tight, it is advantageous if the contact surface 15a is nevertheless in their areas in the immediate vicinity of the contact points is little elastically deformable. The areas of the contact surface 15a that are distant from the contact points should, however, in any case not be deformed noticeably by the contacts. The contact member 15 and the contact layer should therefore have a relatively large modulus of elasticity. The contact surfaces 15a and 25a should be as flat and smooth as possible, but preferably for the in the manner described in more detail, for example, vibrating bodies 45 rolling on them, as the case may be, produce medium to high friction and cause as little noise as possible during operation. The sealing body 13 forming the seals 13b, 13c, 13d, 13e should be deformable as well as possible in comparison with the contact member 15 and the contact layer 21 and preferably also have a large volume change, ie compressibility, and / or be arranged such that through the conveying surface 45a Compression caused by the seals can be compensated by expansions directed approximately transversely to the compression directions. Accordingly, the sealing body 13 should consist of a material whose modulus of elasticity or, more precisely, linear expansion modulus of elasticity or Young's modulus of elasticity is substantially smaller than that of the materials of the contact body 15 and the contact layer 21 and of course also of the ring 11. Furthermore, the sealing body is also intended 13 forming material have a greater Poisson constant than the materials forming the contact element 15, the contact layer 21 and the ring 11. Furthermore, the seals 13b, 13c, 13d, 13e should only generate the lowest possible frictional forces when the conveying surface 45a of the conveying member 41 touches them. Therefore, when the conveying surface 45a contacts the seals 13b, 13c, 13d, 13e and the contact surfaces 15a, 21a, the coefficient of friction resulting when the seals contact the conveying surface should advantageously be smaller than the coefficient of friction which occurs when the contact surfaces 15a contact , 21a with the conveying surface 45a. As can be seen from FIG. 2, the surfaces of the seals 13b, 13c, 13d, 13e contacting the conveying surface 45a have a size which is substantially smaller than the total size of the two contact surfaces 15a and 21a and for example at most 30% or more is better than 20% of the total size of the contact areas. Furthermore, both the sealing body 13 and the contact member 15 should of course be fluid-tight or at least liquid-tight. In addition, the sealing body 13, the contact member 15 and the contact layer 21 should be as abrasion-resistant as possible and non-toxic.

To meet these conditions, the sealing body 13 consists of a rubber-elastic material, namely, for example, a closed-cell porous silicone foam rubber. The contact member 15 and the contact layer 21 consist, for example, of a material which has at least one plastic, namely namely made of aromatic polyamide fibers, which are connected with a binder consisting of a synthetic resin, such as aromatic polyamide.

The transducer 43 of the transducer means has at least one layered, piezoelectric element and, for example, two such. The or each piezoelectric element is formed, for example, from an annular disk made of ceramic material, such as lead zirconate titanate, and is provided with electrodes. A possible design of a transducer for generating vibrations and / or waves of the desired type described in more detail is known, for example, from EP-A-0 169 297, to which reference is hereby expressly made. The transducer disclosed in this publication has two circular, piezoelectric disk-shaped elements and electrodes arranged one above the other. The oscillating body 45 should have good oscillation and waveguiding properties for elastic waves with frequencies in the sound and in particular ultrasound range and should also be abrasion-resistant and non-toxic. The vibrating body 45 is preferably made of a metallic material such as Aluminum or stainless steel. Otherwise, the dimension of the vibrating body measured parallel to the axis of rotation is, for example, larger than the dimension of the transducer 43 measured in the corresponding direction and can be at least 5 times and even approximately or at least 10 times the said transducer dimension. If the transducer 43 and the vibrating body 45 according to FIG. 1 have the same inside and outside diameters in pairs, the same minimum values then also apply to the ratio between the volume of the vibrating body and the volume of the transducer. The electronic device 61 has circuit means for generating a periodically repeating sequence of electrical signals, so that it performs the function of a signal generator and / or oscillator. A possible design of the electronic device is also known from EP-A-0 169 297 already cited.

The spring 55 acts on the conveying member 41 with a force directed against the ring 11, the size of which can be adjusted to a favorable value with the nut 51 serving as an adjusting member. Furthermore, the rubber-elastic sealing body 13 engages on the side facing away from the contact surface 15a of the contact member 15 and presses the contact member 15 against the conveying member 41. Since, moreover, the conveying surface 45a of the oscillating body 45 in the rest state is the same as the contact surfaces 15a and 21a facing it , it rests in the idle state along a whole circle enclosing the axis of rotation 5 on the contact surfaces 15a and 21a and the seals 13b, 13c, 13d, 13e with a certain pressure force, so that the contact surfaces 15a, 21a also lie in a common plane .

In operation, the electronic device 61 leads the Transducer 43 produces a sequence of excitation signals formed by pulses or sine half-waves of electrical excitation voltages in such a way that the converter carries out oscillating movements and thereby excites an elastic wave which moves inside the oscillating body 45 in the direction of rotation indicated by the arrow 71 in FIGS. 2, 3 and 4 spreads around axis 5. An elastic wave generally consists of two superimposed waves, namely a longitudinal wave causing shifts in the direction of propagation and one

Shifts transversely to the direction of propagation causing the transverse wave, the longitudinal wave having a greater propagation speed, ie phase speed, and incidentally also a greater group speed than the transverse wave. The elastic wave or, if one considers the longitudinal wave and the transverse wave as separate waves, each elastic wave, should preferably have a frequency in the ultrasound range and therefore a frequency above about 20 kHz and for example also above about 30 kHz. A surface wave then occurs on the conveying surface 45a of the vibrating body 45 of the conveying member 41, as is also known under the name Rayleigh wave. The conveying surface 45a is deformed by this surface wave in such a way that, in a section along a cylindrical surface coaxial with the axis of rotation 5, it forms a continuously curved wavy line with troughs 73 and from these in the axial direction, ie parallel to the axis of rotation 5, wave crests 75 projecting towards the ring 11 . The wave troughs 73 and wave crests 75 extend across the entire width of the conveying surface 45a transversely to the direction of propagation of the surface wave, ie in the direction radial to the axis of rotation 5. The latter is thus cut in a section that is perpendicular to the plane that it spans at rest and transverse to the direction of propagation of the surface. Chenwelle runs, not or at most significantly less curved than in a section along a cylindrical surface coaxial to the axis of rotation 5. The crests of the waves 75 rest against the contact surfaces 15a, 21a, while the regions of the conveying surface 45a forming the troughs 73 are separated from the contact surfaces 15a, 21a by a free space. The contact surface 15a of the contact member 15, the section of the conveying surface 45a facing the contact surface 15a and the deformable sections of the seals 13b, 13c, 13d, 13d which protrude beyond the contact surface 15a therefore together limit a conveying passage 77 for what is to be pumped by the pump and fluid to be pumped. The deformable seals 13b, 13c, 13d, 13e thus serve as the conveying passage 77 at its arcuate edges and at its ends, that is to say at the confluence of the fluid connections 17, 19, sealing means which enable sealing movements of the conveying surface sections present there.

The conveying passage 77 which results during operation is therefore largely limited by the surfaces 15a and 45a forming its broad sides in cross section, while the seals 13b, 13c, 13d, 13e only the very small gaps between the contact surface 15a and the

Complete wave valleys 73. The conveying member forms in the conveying passage 77 fluid-absorbing cells 79, the bottom of which is formed by a wave trough 73 and the ends of which are delimited and separated from one another by the ridges formed by the wave crests, so that the wave crests 75 are the end limits of the cells 79 serve.

A region of the conveying surface 45a located at the apex of a wave crest 75 moves when Operation along a closed path 81 which forms an ellipse or possibly a circle in the development shown in FIG. 3. It should be noted that in Figures 1, 3 and 4 the wave height is drawn in a disproportionately large size and the web 81 in an even more exaggerated size. Since the apex regions of the wave crests 75 touch the contact surface 15a of the contact member 15 or the contact surface 21a of the contact layer 21, when they move, they generate a circle surrounding the axis of rotation 5 as a result of the friction between the contact surfaces 15a, 21a and the conveying surface 45a tangential rolling and / or thrust. The wave crest areas therefore roll to a certain extent on the contact surfaces 15a, 21a, as a result of which the oscillating body 45 and thus the entire conveying element 41 and the entire rotor 3 are moved in the direction of the arrow 71 and rotated about the axis of rotation 5. While in the motors known from EP-A-0 169 297 already cited, the piezoelectric transducer is fixed with respect to the motor axis of rotation during operation, it belongs to the rotor in the pump described with reference to FIGS. 1 to 4. The direction of rotation of the rotor 3 is thus the same as the direction of propagation of the elastic shaft, but the speed of rotation of the rotor is very much lower than the phase speed of the elastic shaft and the phase speeds of its components.

The conveying member 41 can be caused to oscillate by an elastic shaft running around the axis of rotation 5 with one of its possible resonance frequencies. The

Resonance frequencies are determined by the vibratable parts of the conveying element 41, ie by the transducer 43 and above all by the vibrating body 45 which normally has a substantially greater mass than the transducer. As already mentioned, the longitudinal and Transversal wave that propagate inside the vibrating body, different phase velocities. Since the phase velocity is equal to the product of frequency and wavelength, the two waves have different wavelengths at the same frequency. The surface wave generated on the conveying surface 45a has at least approximately the same wavelength as the transverse wave. A resonance arises in the types of waves or oscillations of interest if the length of the circular wave path is equal to the wavelength or an integral multiple thereof, the length of the wave path depending on the path radius under consideration. Since above all the surface wave is decisive for the pump behavior, a resonance frequency is understood below to mean a frequency at which the surface wave running along the circular center line of the conveying surface is in resonance and its amplitude has a relative maximum.

The frequency of the excited wave should preferably correspond at least approximately and advantageously exactly equal to a possible resonance frequency, for example the fourth order resonance frequency, so that a wave with four wave peaks 75 distributed uniformly around the axis of rotation 5 is formed on the conveying surface 45a. So that the electronic device 61 generates a sequence of signals whose repetition frequency corresponds exactly to a resonance frequency, the electronic device is advantageously provided with a manually adjustable actuator for setting the frequency and / or with control circuit means for automatically adjusting the exact resonance frequency value. For example, the manually adjustable actuator can be used to set a frequency range containing the resonance frequency of the desired order, so that the automatic control circuit means then adjust the frequency of the excited wave to the resonance frequency of the order in question during operation.

The surface wave present on the conveying surface 45a and the wave-shaped deformation of the conveying surface 45a caused thereby can proceed in the direction of the arrow 71 with respect to the conveying member in the same way as the elastic wave present in the inside thereof. The wave crests 75 of the conveying surface 45a then move in the direction indicated by the arrow 71 around the axis of rotation 5, the speed of the wave crests relative to the stator 2 being equal to the sum of the propagation speed of the surface wave measured with respect to the rotor 3 plus the speed of the

Rotor 3 is. The seals 13b, 13c, 13d, 13e nestle against the conveying surface 45a in a fluid-tight manner both in the wave crests 75 and in the wave troughs. The fluid flowing through the connection 17 into a cell 79 is converted by the wave crest delimiting it at the rear end with respect to the direction of rotation and conveyance and / or possibly also by the static friction on the rest of the region of the conveying surface 45a delimiting the cell 79 in question Port 19 promoted so that the pump sucks in fluid at the port 17 serving as the inlet and pumps out fluid at the port 19 serving as the outlet.

The pump can easily be dimensioned and operated in such a way that even when pumping a fluid with very small, for example at most or less than

10 mm ³ / min and, for example, pump or delivery rates of at least 0.1 mm3 / min, a sufficiently precise dosage is possible. The pump can therefore be used to produce a pharmaceutical active substance with a very low feed rate can be introduced into a body tissue without having to dilute the active substance greatly, as was often necessary in the case of previously known cell pumps having a rotor.

In FIG. 3, lambda denotes the wavelength, measured along the curved center line of the conveying passage, from the apex of a wave crest 75 to the apex of the next wave crest 75 of the wave deforming the conveyor surface 45a. This wavelength should be smaller than the distance c measured in the same way between the mutually assigned edge points of the mouths at which the connections 17 and 19 open into the conveying passage 77, and accordingly of course also smaller than the distance measured in the same way d of the mutually facing edges of the surface with which the seals 13d and 13e bear against the conveying surface. The distances c and d should therefore be greater than the stated wavelength and, for example, as shown in FIG. 3, may be smaller than twice the wavelength and namely be at most about 150% of this. In the event that the mouths of the two connections do not lie on the same circular line coaxial with the axis of rotation 5 and / or that the edges of the seals 13d and 13e do not run radially, the conditions mentioned should be those for the wavelength and the distances c and d , apply around the axis of rotation 5 measured central angle, then the angularly most distant locations of the two mutually facing sealing edges are to be considered. If the said wavelength and the dimensions c, d are matched to one another in this way, the conveying element 41 is at any time during pumping in a state in which at least one wave crest 75 forming the end boundary of a fluid-containing cell 79 lies between the mutually facing edges of the mouths of the two connections in the conveying passage at least approximately and preferably lies completely tight on the contact surface. It should be noted here that the pressure of any liquids present in the body tissues of humans and animals is generally approximately equal to the atmospheric pressure prevailing in the environment or at most only slightly greater than this. A wave crest 73 contacting the contact surface 15a should therefore normally be sufficient to at least approximately completely and completely avoid a backflow of fluid against the intended conveying direction through the conveying passage and for practical purposes.

If, however, a more complete non-return valve is desired, the pump can also be modified in such a way that when pumping in any possible state of the delivery element and thus in any possible position thereof, wave crests 75 which form at least two end boundaries of cells between the mouths of the two connections 17, 19 and the mutually facing edges of the seals 13d, 13e, as shown in FIG. 5, where the distances c and d are more than 2 times and less than 3 times the wavelength. Such a relationship between the distances c and d and the wavelength can be achieved with constant inner and outer radii of the contact and the conveying surfaces by increasing the central angular distances between the two connection mouths and the seals defining the two ends of the conveying passage and / or the wavelength is shortened. The latter can be achieved by increasing the frequency of the generated wave at least to the value of the resonance frequency of the next higher order. Of course, you can also the geometric dimensions of the pump and the wavelength on each other coordinate that at all positions and states of the conveying element which cancel the pumping, there are at least three or even more wave crests in the conveying passage between the two connection mouths.

Of the two surfaces 15a, 45a, the contact surface 15a is continuously flat and the conveying surface 45a is undulating during operation, the wave heights of the conveying surface during operation actually being much smaller than shown in FIGS. 1, 3 to 5 and in particular very much smaller than the wavelength are. In addition, the contact surface 15a and the conveying surface 45a have no discontinuities. The conveying passage also has no dead spaces between the mouths of the two connections 17, 19. The pump therefore conveys the fluid as a thin layer practically continuously and evenly through the delivery passage.

The deformable support and / or support body 35, for example made of felt, dampens the transmission of vibrations of the conveying member 41 to the carrier 33 and thus serves to decouple the conveying member from the carrier 33 in terms of vibrations and to compensate for and compensate for changes in the dimensions of the conveying element which are parallel and / or at right angles to the flat resting shape of the conveying surface 45a as a result of the wave generation.

If no waves are excited in the conveying element and the pump accordingly does not pump, the conveying surface 45a, as already mentioned, is flat and lies in the conveying passage from the mouth of the connection 17 to the mouth of the connection 19 along the conveying direction, namely over the entire contact surface 15a. As a result, the conveying passage 77 is at least approximately and preferably completely sealed, namely to some extent made it disappear. The pump can therefore also be operated intermittently without any problems. This makes it possible to pump a medication into the tissue of a body with periodic shocks and to introduce a prescribed amount of the medication into the tissue approximately every minute at most for 10 to 30 seconds and for example for 15 to 20 seconds, so that the fluid quantity pumped on average per unit of time corresponds to a predetermined funding rate, which is already in the

3 mentioned range from 0.1 to 10 mm / min can be.

Otherwise, the electronic device can be provided with a switch for switching the pump on and off and / or with a switch which makes it possible, by means of the converter 43, to select one of the - as described - in FIG

To produce the direction of the arrows 71 around the axis of rotation 5 around the shaft or a wave propagating in the opposite direction. If a wave propagating against the arrows 71 is generated, the rotor also rotates in the opposite direction, so that the conveying member 41 then conveys fluid from the connection 19 to the connection 17. If necessary, the possibility of changing the delivery direction of the pump can be used, for example, to pump fluid from a reservoir into the above-mentioned reservoir, which may be present and forms a unit with the pump.

A motor which operates according to the principle known from the cited EP-A-0 169 297 and has a piezoelectric transducer for generating ultrasound waves makes it possible to generate a torque which is considerably greater in relation to the volume of the motor than in the case of an electric induction motor. Of course, this also applies to the invention described above according to trained pump. While in prior pumps with a rotating conveying element a separate motor is required to rotate the same, in the pump according to the invention the pump body simultaneously still functions to a certain extent the function of the stator of a motor and the conveying element the function of the motor rotor. In the case of the pump according to the invention described above, it also forms, to a certain extent, a motor and therefore its own drive means. The pump and its drive means can therefore be made relatively small for a given delivery rate.

Since those areas of the conveying surface 45a which touch the contact surfaces 15a, 21a, ie the crest of the crest areas, perform a rolling movement and the conveying member 41 and thus the entire rotor 3 is rotated almost slip-free when the crest of the crest regions on the contact surfaces Touching the conveying surface 45a with the contact surfaces 15a, 21a practically no energy losses due to friction. Furthermore, because the seals 13b, 13c, 13d, 13e touch only a small part of the conveying surface 45a and have relatively good sliding properties, the waves in the oscillating body 45 and its oscillating movements are caused by the contact of the conveying surface 45a with the contact surfaces 15a, 21a and the seals 13b, 13c, 13d, 13e only slightly damped. Accordingly, the rotary movement of the conveying member is braked by the seals only relatively little. In addition, the pump has no gearbox causing friction losses. The pump therefore makes it possible to achieve a high degree of efficiency in the conversion of electrical energy into mechanical energy which produces fluid. Accordingly, the pump requires little electrical energy to operate. The electronic device 61 must be the piezoelectric Converter 43 for pumping a drug with a

3 range from about 0.1 to 10 mm / min lying pump or

Feed rate also only supply relatively small electrical excitation voltages, the value of which is at most 30 V, expediently at most 10 V, preferably at most 5 V and for example only about 3 V. Accordingly, the battery used to power the pump only has to supply a small supply voltage and little current and can therefore be relatively small.

The delivery rate of the pump depends, among other things, on the amplitude A of the surface wave, which in turn depends on the size of the electrical voltage supplied to the piezoelectric transducer. It is therefore possible, for example, to provide the electronic device with an actuator with which the electrical voltage supplied to the converter and thus the delivery rate can be set.

It can also be shown that the speed w at which a point located at a crest of the crest on the center line of the conveying surface moves along a path 81 is at least approximately proportional to the amplitude A and proportional to the axially measured dimension h of the vibrating body. Provided that the rotor is rotated without slip, the conveying surface moves around the axis of rotation 5 at the speed w. For example, if the average diameter of the conveyor surface is 20 to 30 mm, the frequency is approximately 50 to 70 kHz, the wavelength λ is a quarter of the circumference of the center line of the conveyor surface and the dimension h is made approximately 1 to 5 mm and surface waves are in the range of approximately 1 to 5 microns lying amplitudes are generated, the speed w becomes very much. namely at least about 1000 times less than the phase velocity of the wave.

There may also be the possibility of generating a wave in the conveying member 41, the frequency of which deviates more or less from one of the possible resonance resonance frequencies of the conveying member.

The pump, of which some parts are shown schematically in FIGS. 6 and 7, has a pump body 101 with a stator 102 and a rotor 103 which is rotatably mounted about an axis of rotation 105 with bearing means, not shown. The stator has a dimensionally stable ring which corresponds functionally to the ring 11 of the pump described above, but at the same time serves as a contact element 111 and is delimited on one end face essentially by a contact surface purple at right angles to the axis of rotation 105. In a sector of the contact surface lilac there is a groove 111b running along a closed curve, into which a sealing body 113 is inserted, which consists of a self-contained, ie. H. there is a completely continuous ring and forms four seals 113b, 113c, 113d, 113e. The stator is also provided with two fluid connections 117, 119, which open into the area of the contact surface 111a enclosed by the sealing body 113.

The rotor 103 has an annular conveying element 141 which is held by a carrier (not shown) and which can be designed analogously to the conveying element 41 and has transducer means with a piezoelectric transducer 143 and an oscillating body 145 with a conveying surface 145a.

The ring-shaped contact member 111 is, for example a plastic, approximately the same composite plastic consisting of fibers and a binder as the contact member 15 and the contact layer 21 of the pump described above, so that the contact surface purple and the region of the contact member 111 forming this have similar properties as the contact surfaces 15a and 21a and the contact member 15 and the contact layer 21. However, the contact member 111 could also be made of some other dimensionally stable material. If this material is not the one required for the contact surface

Has properties, the ring serving as the contact element can also be provided on its end face facing the conveying element with a coating suitable for forming the contact surface.

When the pump shown in FIGS. 6 and 7 is in operation, the conveying surface 145a is deformed in a wave shape by the shaft generated in the conveying member in such a way that wave crests protruding in the axial direction are formed analogously to the conveying surface 45a. The ring-shaped

Sealing body 113 enclosed area of the intermediate space between the facing end faces of the contact member 111 and the annular vibrating body 145 then serves as a conveying passage 177, through which fluid can be conveyed analogously as through the conveying passage 77.

The pump shown in FIGS. 8 and 9 has a pump body 201 with a stator 202 and a rotor 203 which is held by the stator 202 so that it can rotate about an axis of rotation 205. The pump body has a ring 211 which surrounds the axis of rotation and which each extends over a circular sector, dimensionally stable ring sectors, namely formed from two ring parts designated 207 and a ring part designated 209. The ring parts are at their mutually facing ends by connecting elements 223 connected in pairs such that they can be moved to a limited extent in the radial direction with respect to the axis of rotation 205. The required radial mobility is very small compared to the inner and outer radii of the ring parts, so that the widths of the gaps between the ring part ends can be very small compared to the circumference of the ring. The two ring parts 207 have on their inner side facing the axis of rotation 205 a surface 207a which forms part of a cylindrical surface coaxial with the axis of rotation. The third ring part 209, which extends for example over a somewhat larger central angle than the other two ring parts 207, is provided on its inside facing the axis of rotation with a recess 209b, namely a groove running in an arc around the axis of rotation. In this sits an arch-shaped, shell-shaped and / or trough-shaped, rubber-elastic sealing body 213, which can be seen particularly clearly in FIG. 10, which is provided on its side facing the axis of rotation 205 with a recess 213a and, for example, has a cross-sectional shape similar to that of the sealing body 13 The four edge sections of the sealing body 213 enclosing the recess 213a each form a seal 213b, 213c, 213d, 213e analogously to the sealing body 13, these seals being connected in pairs at their ends. A contact member 215 is seated in the recess 213a. This is delimited on its side facing the axis of rotation 205 by a smooth, arc-shaped contact surface 215a which forms part of a circular cylindrical surface coaxial with the axis of rotation 205. The stator is also provided with two fluid connections 217, 219 opening into the contact surface 215a. The surfaces 207a of the two recessed ring parts 207 facing the axis of rotation are provided with a contact layer 221, the sides of which facing the axis of rotation serve as contact surfaces 221a, each of which is part of a Circular cylinder surface forms.

The main component of the rotor 203 is a conveyor element 241 with transducer means, namely a piezoelectric transducer 243, and an oscillating body 245. The latter consists of a one-piece disk with a circular outline in the idle state and is delimited along its circumference by a conveying surface 245a which is circular-cylindrical in the idle state and which, in the manner explained above, for the conveyance of fluid and also in cooperation with the contact surfaces 215a, 221a facing it for the radial mounting of the conveying member 241 and thus the entire rotor 203 is used. For axial mounting, pin-shaped bearings 225 are provided as additional bearing means, for example, on both end faces of the conveying element 241, for example at the central regions of the end faces of the oscillating bodies, which are each connected to ring parts of the ring 211 by means of a bracket or the like. It should be noted here that the peg-shaped bearings can, if necessary, also be provided with means for damping and decoupling vibrations or could be replaced by a bearing with rolling elements, such as balls. An electronic device 261 and a battery 263 are attached to the conveyor member 241 via supports 235 for vibration damping and decoupling, the electronic device and battery being connected to electrodes of the piezoelectric transducer 243 and to one another by electrical conductors (not shown).

The sealing body 213, the contact member 215, the contact layer 221 and the oscillating body 245 consist, for example, of materials which have the same properties as the corresponding parts of the pump described with reference to FIGS. 1 to 4. Instead of the spring 55 present in this case, the spring shown in FIGS 9 and 9, a pump shows a rubber-elastic band 255 which surrounds the ring parts 207 and which acts on the ring parts 207 with a force directed radially towards the axis of rotation 205 and thereby resiliently presses the contact surfaces 215a, 221a against the conveying surface 245a.

The piezoelectric transducer 243 has at least one piezoelectric element, for example in the form of an annular disk, which can be made of the same material as that of the transducer 43. The transducer 243 and the electronic device 261 are designed to excite an elastic wave, namely an ultrasonic wave, which propagates in the conveying element 241 and in particular in its oscillating body 245 in the direction of arrow 271 around the axis of rotation 205. The shaft should be designed in such a way that the conveying surface 245a, which is circular-cylindrical in the idle state, is deformed by a surface wave in such a way that troughs 273 and wave crests 275 projecting outward in a radial direction perpendicular to the axis of rotation 275 are formed, as is the case in the greatly exaggerated size in the figure 9 is shown. A configuration of a piezoelectric transducer that enables the generation of such ultrasonic waves is known, for example, from FR-A-2 522 216, to which express reference is hereby made.

The wave generation should advantageously take place analogously to that of the pumps shown in FIGS. 1 to 4 in such a way that the conveying member is made to vibrate with a resonance frequency, for example the fourth-order resonance frequency, and accordingly four wave peaks 275 are distributed over the circumference of the conveying surface 245a. The contact surface 215a then delimits, together with the seals 213b, 213c, which protrude at least temporarily and / or in places toward the axis of rotation, 213d, 213e and the conveying surface 245a a conveying passage 277 with cells 279, the end boundaries of which are formed by the wave crests 275. The apex regions of the wave crests 275 move on elliptical orbits, one of which is shown in FIG. 9 and is designated 281 and lie in the planes perpendicular to the axis of rotation. The surface wave causes a rotation of the rotor 203 in the direction of the arrow 271 analogously to the pump shown in FIGS. 1 to 4. Furthermore, fluid can also be conveyed from the connection 217 to the connection 219 analogously to the pump according to FIGS. 1 to 4 .

The pump, of which only a few parts are shown in FIGS. 11 and 12, has a pump body 301 with a stator 302 and a rotor 303, which is rotatable about an axis 305. The stator 302 has a ring 311, which has three ring sectors connected to one another, namely two ring parts 307 and a contact element 309, and is of similar design to the ring 211, but differs from the stator 202 in that the ring sector serving as the contact element 309 is used instead of the shell-shaped and / or trough-shaped sealing body 213, an annular sealing body 313 is used, which serves to limit the conveying passage. The contact surface 309a located in the region of the conveying passage is accordingly formed by a surface of the contact member 309, but could of course also be formed by a coating applied thereon if necessary. The rotor 303 has a conveying member 341, which can be designed, for example, the same or similar to the conveying member 241 and has an oscillating body 345 with a circularly cylindrical conveying surface 345a in the idle state. When the pump shown in FIGS. 11 and 12 is operating, the delivery surface 345a becomes analogous to that Conveying surface 245a deformed. The pump according to FIGS. 11 and 12 accordingly works similarly to the pump with the parts shown in FIGS. 8 to 10.

The pump shown in FIG. 13 has a pump body 401 with a stator 402 and a rotor 403 rotatable about an axis of rotation 405. The stator has a ring 411, which on its inside has a surface which widens conically towards the conveying member of the rotor and which has a sector serving as contact surface 411a and a sector with a recess 411b. A shell-shaped and / or trough-shaped sealing body 413 is seated therein, in which a contact element 415 is embedded with a contact surface 415a forming part of a conical surface. The edge sections of the sealing body form the

Contact surface 415a sealing seals. There are also two fluid connections 417, 419 opening into the contact surface 415a. The rotor 403 is mounted in a similar way to the rotor 3 and, like the latter, is subjected to a force by a spring, which the conveying element

441 presses against the ring 411 of the stator. The conveying member 441 has a piezoelectric transducer 443 and a vibrating body 445, the outer or outer surface of which forms a conical conveying surface 445a in the idle state.

When the pump shown in FIG. 13 is in operation, the transducer 443 excites an elastic ultrasound wave that propagates in the conveying element in a direction around the axis of rotation 405, so that a surface wave is produced on the conveying surface 445a, of which two wave crests 475 are narrow by one group each adjacent strokes are indicated. The wave excitation can take place in such a way that the wave crests protrude at right angles to the conical conveying surface 445a over the wave troughs and that the wave crest crests move, for example, on tracks, which run along a conical surface crossing the conical conveying surface at right angles. However, one could possibly also excite waves in which the wave crests of the conical conveying surface 445a move along paths lying in a cylindrical surface like the radial conveying surface 45a or along ellipses lying in a radial plane like the conveying surface 245a. During operation, the rotor 403 is rotated analogously to the rotor 3, the conveying member 403 conveying fluid from one connection to the other.

In the figures 14 to 20 described below, the directions in which the conveying surfaces are deformed from their idle state to form wave troughs and wave crests are indicated by double arrows.

In the rotor 503 shown in FIG. 14, its conveying member 541 or at least its oscillating body 545 forms a circular, compact, ie. H. plate with no central hole. The wave excitation takes place in such a way that wave peaks are formed on the conveying surface 545a, which is perpendicular to the axis of rotation 505 in the idle state, and project in the axial direction from the wave troughs.

FIG. 15 shows a rotor 603 which can be rotated about the axis of rotation 605 and whose conveying element 641 has an oscillating body 645. This has a flat plate perpendicular to the axis of rotation and an annular rib projecting axially therefrom, the end of which faces away from the plate forms the conveying surface 645a perpendicular to the axis of rotation 605 in the idle state. Protruding wave crests are formed on this during operation in the axial direction.

The ring-shaped conveying element 741 that can be seen in FIG. 16 and rotates about an axis of rotation 705 has one Vibrating body 745, one end of which forms the conveying surface 745a. The latter consists of two oppositely conical partial surfaces, which together form an angle in cross section, the legs or tips of which protrude in the axial direction from the remaining part of the conveying member. The wave crests protrude in the axial direction away from the wave troughs.

The ring-shaped conveying element 841 shown in FIG. 17 has an oscillating body 845, the conveying surface 845 of which is formed by the outer circumferential cylindrical surface in the idle state. As with the conveying element 241, the wave excitation takes place in such a way that the wave crests project outward from the wave troughs radially to the axis of rotation 805.

FIG. 18 shows an annular conveyor element 941 rotatable about an axis of rotation 905 with an oscillating body 945, the outer surface of which serves as the conveyor surface 945a. This consists of two oppositely conical partial surfaces, which together form an angle with the apex protruding outwards. During operation, the transducer means of the conveying element 941 excites an ultrasonic wave, which deforms the conveying surface 945a in such a way that wave crests projecting radially outwards.

The ring-shaped conveying element 1041 shown in FIG. 19 and rotatable about an axis of rotation 1005 has an oscillating body 1045. In this variant, the conveying surface 1045a is formed by the inner cylindrical surface of the oscillating body 1045, which is cylindrical in the idle state, and is deformed in an undulating manner during operation in such a way that radial and wave crests protruding at right angles to the axis of rotation 1005 arise. The annular conveyor element 1141, which is designed according to FIG. 20 and can be rotated about an axis of rotation 1105, has an oscillating body 1145. This has a conical inner surface, which serves as the conveying surface 1145 and is conical in the idle state, which is deformed in a wave shape during operation in such a way that it is perpendicular to its surface lines inside, ie protruding wave crests are formed towards the axis of rotation 1105. The apex regions of the wave crests accordingly move analogously to the conical conveying surface 445a on tracks which lie in a cone surface at right angles to the conical conveying surface 1145 which is conical in the idle state.

The stators (not shown in FIGS. 14 to 20) are of course designed in such a way that they have contact surfaces analogous to the previously described pumps according to the invention and, together with the conveying members, limit conveying passages through which a fluid can be conveyed.

It is also possible to provide for the formation of a conveying passage which extends approximately over a full circumference. In this case, the two ends of the conveying passage can be separated from one another by one and the same seal, so that this seal therefore delimits both ends of the conveying passage. Such a pump is per se possible with a radial, circular cylindrical and conical contact surface. In FIGS. 21 and 22, pumps are shown in a highly schematic manner in which the two ends of the conveying passage are through the same

Seal are limited. For reasons of clarity, the pumps are drawn with a circular cylindrical contact surface, although pumps with radial delivery passages extending over such a large central angle give certain advantages and, in particular, with structurally simpler means enable the contact and conveying surfaces to be pressed resiliently against one another.

The pump shown in FIG. 21 has a pump body 1201 with a stator 1202 and a rotor 1203. The stator has a ring 1211 which is drawn in one piece, but possibly in several parts in the same way as the ring 211. A one-piece sealing body 1213 arranged on the inside of the ring 1211 has two ring-shaped seals, each completely enclosing the axis of rotation and separated by an intermediate space in the axial direction lateral seal 1213b sections and a web connecting them at a circumferential point to the axis of rotation parallel, which forms a seal 1213d. A contact element 1215 is arranged in the edge of the inside of the ring 1211 enclosed by the seals and forms a circular cylindrical contact surface 1215a on its side facing the axis of rotation. Two fluid connections 1217 and 1219 open on opposite sides of the seal 1213d in the vicinity thereof in the contact surface 1215a.

The rotor 1203 has a conveying member 1241 with a vibrating body 1245, which forms a circularly cylindrical conveying surface 1245a in the idle state. During operation, this is deformed in a wave shape such that two opposing wave troughs 1273 and in between two wave crests 1275 and a conveying passage 1277 are formed. The latter extends from one side of the seal 1213d to the other side thereof and thus approximately along an entire circular line, namely over a central angle of at least 300 °.

The pump according to FIG. 22 is largely similar designed like the pump shown in FIG. 21, but differs from it in that the piezoelectric transducer means of its delivery member 1341 generate a shaft during operation, which deforms the delivery surface 1345a of the oscillating body 1345 in such a way that three troughs 1373 distributed over the circumference and, of course, three wave crests were created in 1375.

Of course, in pumps of the type shown in FIGS. 21 and 22, waves can be excited which form even more wave peaks distributed over the circumference. Furthermore, it might even be possible to generate a wave with the basic resonance frequency of the vibrating body, so that only a single wave crest is created on the conveying surface. When the rotating conveying element in such a pump reaches a rotational position in which the wave crest is located at the seal corresponding to the seal 1213d, a state arises in a short period of time in which the conveying passage is open over its entire length. Wave excitation with the basic resonance frequency is therefore not very favorable and would only be usable for purposes in which either there is no back pressure at the fluid outlet or a certain fluid backflow is acceptable.

FIG. 23 shows a pump with a pump body 1401, the stator 1402 of which, together with the delivery member 1441 of the rotor 1403, delimits two delivery passages 1477, each of which extends over a central angle of less than 180 °. The stator is accordingly provided with two fluid connections 1417, 1419 for each conveying passage. The converter means of the conveying element 1441 can excite a shaft when operating such a pump, which forms, for example, six wave crests 1475 on the conveying surface 1445a of the oscillating body 1445. Such a pump with two fluidly separate delivery passages allows two liquid medications to be pumped separately into the same or different body tissues of a patient, which can be advantageous in certain cases. The pump shown in FIG. 23 has a circularly cylindrical delivery surface in the idle state, but could of course also have a radial or conical delivery surface in the idle state.

The pumps having a rotor can be modified in other ways. If, for example, in the pump according to FIGS. 1 to 4 and in the pump according to FIGS. 8 to 10, the contact of the conveying surface 45a or 245a with the contact surface 15a or 215a located in the conveying passage is sufficient to rotate the rotor during operation, The contact layers 21 or 221 can be omitted, so that the conveying surfaces there have no contact with the stators and therefore only touch the stators in the conveying passage 15a, 215a and the seals. This can reduce the damping of the excited waves.

Furthermore, one could possibly convey the pumping elements in their oscillating bodies, elastic waves during pumping, non-rotatably connecting them to the contact elements. Since the crests of the wave crests formed by the pumping surfaces no longer roll on the contact surfaces, but rather slide over them, the contact surfaces are then advantageously formed as smoothly as possible. If there is no need for a rotatable mounting of the conveying elements, this could also be formed from a ring which, instead of being circular, is, for example, elliptical or oval, in which case waves that propagate along an elliptical or oval, flat, closed path could be generated.

In the previously described embodiments of the Pumps according to the invention are excited in the conveying elements during operation along a circular line or possibly another closed, flat path, continuously expanding elastic waves. The frequencies of the waves are matched to the shapes, geometrical dimensions and material properties of the conveyor elements in such a way that they preferably have exactly the values of possible resonance frequencies or at most deviate relatively little from such resonance frequencies. This makes it possible to achieve a wave amplitude sufficient to achieve the desired delivery rate with pumps having relatively small dimensions and with relatively small electrical voltages supplied to the piezoelectric transducers.

Embodiments of pumps, however, are now to be described, in which an effective deformation of the conveying surfaces is possible without continuously exciting waves which propagate along closed paths and produce resonances. With these pumps, which are described in more detail below, the conveying passages therefore do not necessarily have to run along closed paths, but can optionally run along straight lines and / or curves. Furthermore, the conveying members need not be rotatable with respect to a stator, but can - apart from the deformation movements serving to produce more or less wave-like deformations of the conveying surfaces - be stationary with respect to the rest of the pump body.

Figures 24 and 25 show an embodiment of such a pump with a rotorless pump body 2001. This has a flat plate 2009 and a hood 2011 rigidly connected to it, which together with the dimensionally stable wall of a chamber closed on all sides at least generally form a rectangular outline. A rubber-elastic sealing body 2013 is arranged in the interior of the chamber, which is provided with a recess 2013a and forms a trough or shell with an approximately cuboidal outline. A dimensionally stable contact element 2015 is held in the recess 2013a, which has the shape of an elongated straight plate or strip and forms a flat, elongated contact surface 2015a. The edge sections of the sealing body 2013 form seals analogously to the previously described pumps, of which the two seals 2013b, 2013c run along the longitudinal edges of the contact surface 2015, namely, parallel to the direction of delivery of the pump, while the two seals 2013d, 2013e along the two shorter ones Edges of the contact surface and transverse to the conveying direction. Two fluid connections 2017, 2019 penetrate from the surroundings through the hood 2011 and form passages opening into the contact surface 2015a.

In the interior of the chamber formed by the pump body 2011, an elongated, strip-shaped conveying element 2041 with transducer means, namely a piezoelectric transducer 2043, is arranged. This has a layered, piezoelectric element 2044 and a bending body 2045 with a conveying surface 2045a facing the contact surface 2015a. This is flat in the idle state and can be bent in a wave-shaped manner in operation in a section running in the longitudinal direction of the conveying member, as is shown in FIG. 24 with a greatly exaggerated wave height. The wave troughs 2073 and wave peaks 2075 that arise when the conveying surface 2045a bends extend across the entire width of the conveying surface transversely to the conveying element 2041, as can be seen in FIG. The conveyor surface 2045a is thus in a cross-section to the conveyor member Cut not curved or at most significantly less curved than in a longitudinal section. The wave-shaped deformation of the conveyor member 2041 and the transducer 2043 which at least essentially forms it also causes changes in length of the conveyor member and its sections. If the conveying surface is bent in a wave shape starting from its flat resting shape, the conveying element is shortened a little. The conveying element 2041 is held in the chamber delimited by the plate 2009 and the hood 2011 in such a way that it is undulating when pumped

Bend the conveying surface necessary deformations and thereby also change its length a little, but apart from that it is at rest with respect to the rest of the pump body and, in particular in contrast to the conveying members of the previously described pumps having a rotor, as a whole with respect to the contact surface 2045a moved parallel to the conveying direction. At the edges of its conveying surface, for example, the conveying member can rest on shoulders formed by an extension 2011a of the interior of the hood 2011 and on its side facing away from the conveying surface 2045a via a layered, somewhat deformable support and / or support body 2035 made of felt, for example of the 2009 record.

The material of the contact element 2015 should have a much greater modulus of elasticity than that of the sealing body 2013. The sealing element 2013 and the contact element 2015 can also have properties that are largely similar to those of the corresponding components of the pumps having a rotor described above. However, while it may be favorable for the latter that the contact surfaces result in a certain minimum friction when the conveying surfaces are touched, this is not necessary for the contact surface 2015a. The contact surface 2015a can therefore be as smooth and completely as possible be designed with low friction. The sealing body 2013 thus consists, for example, of a silicone foam rubber, while the contact element 2015 can consist, for example, of a fiberless, dimensionally stable plastic. In addition, the sealing body 2013 and / or the possibly somewhat resilient support and / or support body 2035 should press the contact member 2015 and the conveying member 2041 resiliently against one another, so that the overlapping regions of the contact surface 2015a and the conveying surface 2045a in the idle state everywhere and during operation at the apexes of the wave crests 2075 of the conveying surface bear against one another with a certain compressive force.

The one-piece strip-shaped, piezoelectric element 2044 consists of ceramic, piezoelectric material, namely lead zirconate titanate, as is available on the market, for example, under the name PZT 5. The bending body 2045 is formed by a coherent, one-piece strip of metallic material, such as stainless steel or aluminum.

The piezoelectric element 2044 and the bending body 2045 have at least approximately or exactly the same outline dimensions in the viewing direction perpendicular to the undeformed conveying surface and are connected to one another everywhere in their mutually facing, overlapping surfaces, one of which, for example, forming the connection to the ceramic element of the transducer Metal layer is evaporated, with which the bending body is welded or soldered. Otherwise, the bending body on its side forming the conveying surface 2045a can be vapor-coated with a layer of gold analogously to the pumps with a rotatable conveying member. The metallic, electrically conductive bending body 2045 not only forms the conveying surface 2045a, but also an electrode for generating electrical fields in the piezoelectric element 2044. This is provided on its side or surface facing away from the flexible body 2045 with a plurality of exciter electrodes 2047, namely eight distributed over its length and separated from one another by gaps. The piezoelectric element 2044 of the transducer 2043 and the bending body, which also serves as the counter-electrode, measured in the direction perpendicular to the conveying surface 2045a, have, for example, the same or similar thicknesses, which may be approximately 0.5 mm in size. In contrast, the electrodes 2047 preferably much thinner than the piezoelectric element and each consist of a metal layer vapor-deposited thereon. The electrode formed by the bending body 2045 and the electrodes 2047 are connected to an electronic device 2061 by electrical conductors, not shown in FIGS. 24 and 25, which in turn is connected to a battery 2063. The electronic device and the battery are shown schematically in FIG. 24 on the outside of the chamber formed by the plate 2009 and the hood 2015, but can of course still be enclosed by a housing part (not shown), which also has a reservoir (also not shown) for a pumping drug may contain.

As mentioned, the piezoelectric element 2044 of the transducer 2043 consists of a continuous strip. However, one can conceptually divide the transducer into eight transducer sections 2043a, each of which is assigned to an electrode 2047. The section 2044a of the piezoelectric element 2044 belonging to the relevant transducer section 2043a is then at least largely covered by that of the relevant electrode. FIG. 26 shows the section 2044a of the piezoelectric element 2044 belonging to an individual transducer section 2043a, which section is considered to be different from the rest of the element 2044 cut or cut out of this and its interfaces perpendicular to the longitudinal direction of the element are designated 2044b. The piezoelectric, ceramic material is polarized in the manufacture of the transducer with an electric field or, more precisely, pre-polarized in such a way that the polarization denoted by P in FIG. 26 or, more precisely, pre-polarization, in parallel with the undeformed transducer which is at rest to the conveying direction, ie in the longitudinal direction of the converter. Accordingly, the z-axis or third axis of the lead-zirconate-titanate domains belonging to the hexagonal crystal system is parallel to the conveying direction after pre-polarization has taken place. The x-axis or first axis can then be directed, for example, at right angles to the conveying surface, the x and y axes being equivalent in the hexagonal crystal system with regard to the piezoelectric behavior. If there is an electrical voltage difference between the electrode formed by the bending body 2045 and the electrode 2047 assigned to the relevant transducer section 2043a, an electrical field E is created, the field lines of which run at right angles to the direction of the polarization P and thus also at right angles to the conveying direction. In the fieldless state, section 2044a has the shape drawn with full lines in FIG. The field E acting on the section 2044a from the outside causes a deformation, namely a shear, so that the section 2044a assumes the shape shown in broken lines in FIG. The boundary surfaces 2043b, which are perpendicular to the z-axis in the fieldless state, are thus pivoted by the electric field E acting from the outside by axes perpendicular to the direction of polarization and the field direction, which are therefore parallel to the contact and conveying surface, but are perpendicular to the general conveying direction. Further the two surfaces of the section 2044a of the piezoelectric element 2044 which are parallel to the conveying surface 2045a in the idle state are displaced relative to one another in the longitudinal direction of the transducer during the shearing process.

In the following, polarizations and electric fields directed to the right or upwards or, more precisely, polarization vectors and field vectors, are assigned a positive sign, and polarizations or fields directed in the opposite direction are assigned a negative sign. Of the two sections 2044a of the piezoelectric element 2044 shown in FIGS. 27, the one on the left is positive and the one on the right is negative polarized. If, in a thought experiment, a positive field is initially only allowed to act on the left element section, shearing of the type shown in FIG. 26 takes place in this element section. It can now be assumed that the boundary surface 2044b located at the left end of the left element section is held in the position it was in at rest during the shearing process, so that the right end of the left element section moves upwards into the position shown in broken lines and the right element section is also undeformed is moved. In the thought experiment one can now further assume that the left element section is held in its deformed state and that a positive field is now also acting on the negatively polarized, right element section. This field then causes a shear opposite to that shown in FIG. 26, in which the boundary surface 2044b located at the right end of the right element section is pivoted downward, so that the right element section assumes the position shown in broken lines. For the sake of simplicity, this thought experiment assumed that the upper and The lower surfaces of the element sections remain straight during the shearing processes, as is also shown in FIG. 24. In reality, however, the stresses or forces that cause shear in element 2044 and the stresses and forces that arise as a result of the deformations in flexible body 2045 are distributed over the length of the deformed region of the conveyor element, so that in reality it is continuously bent by the shear.

If the polarization and field directions in the various transducer sections are suitably changed over time, the conveying element can be deformed in such a way that its conveying surface 2045a - as already mentioned - is bent in longitudinal section to form a wave which is more or less sinusoidal and in which The longitudinal direction of the conveying element progresses step by step or step by step, as will now be explained with reference to FIG. 28. In the bottom partial diagram of FIG. 28, the polarization directions present in the sections 2044a of the piezoelectric element 2044 belonging to the eight transducer sections 2043a are represented by horizontal arrows. As can be seen, two positively and two negatively polarized element sections 2044a alternate from left to right along the transducer. In the remaining four partial diagrams of FIG. 28, the directions of the electric field E in the eight transducer or element sections and through for four immediately successive time intervals t ₁ , t ₂ , t ₃ , t ₄ are shown - increasing from bottom to top Curves show the shapes of the conveyor surface 2045a caused by the effects of the fields. In the time interval t. all generated fields E are positive. In the subsequent time interval t ₂ , fields are generated whose directions along the piezoelectric element 2044 from section Switch to section, the field being negative for the first element section at the left end. In the third time interval t ₃ , a negative field is generated in all element sections. At time t. fields were created whose directions along the element change from section to section, the field in the first element section being positive. Then the cycle repeats again.

In the time interval t ₁ , the conveying surface 2045a is bent by the shear caused by the electric fields in the piezoelectric element 2044 in such a way that it forms two wave crests 2075, the apex of which - counting from the left - between the second and third or between the sixth and seventh converter section. The wavelength lambda of the wave created by bending the conveying surface thus extends over four transducer sections and is accordingly equal to half the length of the transducer or conveying member. If the fields are changed during the transition from the time interval t ₁ to the time interval t ₂ , the conveying surface changes its shape abruptly. Here, as can be seen, for example, from the first wave crest, the wave jumps to the right by the length of a transducer section and thus by a quarter of the wavelength. Such a jump in the wave also occurs with every subsequent change in the fields.

According to the electrical block diagram shown in FIG. 29, the electronic device 2061 assigns

Generation of periodically changing generator means serving for electrical excitation voltages, for example two signal generators 2065 and 2067, the common ground connection of which is electrically conductively connected to the flexible body 2045, which also serves as an electrode. The signal off Gang of the signal generator 2065 is electrically conductively connected to the excitation electrode 2047 of the first, third, fifth and seventh converter section 2043a and the signal output of the signal generator 2067 to the excitation electrodes 2047 of the remaining converter sections 2043a. The two signal generators are designed and connected to one another and / or a common clock generator such that each of them generates a sequence of electrical excitation voltage signals during operation. The lines 2091 and 2093 in FIG. 30 show the course of the excitation voltage U supplied to the excitation electrodes 2047 by the signal generator 2065 and 2067 as a function of the time t. As can be seen from FIG. 30, each of the two signal generators generates an alternating voltage with a sequence of alternating positive and negative masses, excitation signals which follow one another without interruption, namely rectangular pulses, which are all of equal length and are repeated periodically. The two signal sequences are shifted in time by a quarter of the period and thus by half a pulse duration. The duration of each time interval t ₁ , t ₂ , t ₃ , t ₄ is then a quarter of the period of the signal sequences. In the case of a transducer with sections 2044a of the piezoelectric element 2044 which are polarized according to FIGS. 28 and 29, the fields required for generating a wave which progressively jumps can thus be generated very easily by alternately supplying one of two signal sequences to the electrodes 2047 following one another along the transducer . This is also possible if polarizations of the transducer sections along the transducer are cyclically shifted to the right or left by the length of a transducer section, so that, for example, the first transducer section is negative, the second and third are positive, the fourth and fifth are negative, the sixth and seventh positive and the eighth would be negatively polarized.

Otherwise, the piezoelectric element could also be polarized equally in all transducer sections. In this case, however, the same signal sequence could only be fed to the electrode of every fourth transducer section, so that four different signal sequences would have to be generated accordingly.

When the conveying surface 2045a is bent in the manner described and forms a progressive wave, the wave crests 2075 formed by the conveying surface lie against the contact surface 2015a, while the wave troughs 2073 are separated from the latter by a free space. A conveying passage 2077 with progressing cells 2079, the end boundaries of which are formed by the wave crests 2075, thus arises between the contact surface 2015a and the conveying surface 2045a during operation, analogously to the pumps described above, which have a rotatable conveying member. The seals 2013b, 2013c, 2013d, 2013e serve in the same way as the seals of the pumps described above as elastically deformable closing means, which, at the two longitudinal edges and at the two ends of the conveying passage 2077, are used for pumping between the contact surface 2015a and the troughs of the conveying surface 2045a seal any cavities or openings from the environment. As a result of the wave crests progressing in steps or in a step-like manner, a fluid can be conveyed through the conveying passage in a manner similar to that of the pumps with a rotating conveying element which rotates during operation. When the wave advances, it can temporarily become somewhat flatter during the jump, because the deformation of the conveyor element due to the inertia of this and the fluid to be pumped cannot in reality take place infinitely quickly. This possible flattening of the conveying surface can temporarily reduce the volume of a cell present between two crests of the waveguide of the conveying surface and the cell resiliently pressed against it. With steps or jumps of a quarter of the wavelength, however, the volume reduction of a cell is so small that this "loss" of delivery volume practically does not interfere and the fluid is conveyed peristaltically and practically uniformly through the delivery passage 2077.

It should also be noted here that, if necessary, steps or jumps of the wave can be generated which are less than a quarter of the wavelength, namely, for example, a sixth or eighth of this. One would then have to provide six or eight electrodes 2047 per wavelength and match the fields accordingly to the polarizations. Incidentally, instead of square-wave pulses, the excitation voltage signals could also be formed from differently shaped pulses such as trapezoidal or triangular-shaped pulses, or by the half-waves of a constantly changing alternating excitation voltage, as will be explained with reference to an exemplary embodiment.

The size of the shear resulting in a section 2044a of the piezoelectric element 2044 as a result of an external electric field is given by the piezoelectric coefficient d _{1 5} or the piezoelectric coefficients d _{2 4 of the} same size for the piezoelectric materials belonging to the hexagonal crystal system . These coefficients have the value 5 · 10 ^-10 m / V for the specified lead zirconate titanate. For example, if there are four transducer sections 2043a and element sections 2044a per wavelength are present, the wavelength is fixed at 25 mm and the thickness of the transducer measured at right angles to the conveying surface is 0.5 mm, it can be arithmetically shown that the amplitude of the wave resulting from bending of the conveying surface is neglected by the bending resistance of the bending body 0.028 mm / V becomes. The frequency of the wave can be, for example, in the range from 0.1 to 100 Hz, with the frequency, analogously to a continuously progressing wave, meaning the reciprocal of the period of time with which the wave formed by the conveying surface changes by one step in several steps Wavelength shifts. It is therefore possible to use relatively small electrical excitation voltages supplied to the electrodes whose amplitudes are at most 100 V, preferably at most 60 V, for example at most 30 V or even only at most 10 V, a delivery rate in the desired size range of 0.1 to 10 mm ³ / min and achieve a sufficient fluid pressure. The electronic device can, for example, be provided with a manually adjustable setting element for setting the frequency in order to set the desired delivery rates, but the delivery rate can of course also be brought to a desired value by means of an adjusting element for setting the magnitude of the electrical voltages supplied to the electrodes.

Furthermore, the metallic, electrically conductive bending body 2045 forms the counterelectrode which is resiliently connected to ground for all excitation electrodes 2047 which are separated by gaps and extends over the length range of the transducer which it occupies and namely over its entire length. The bending body therefore shields the conveying passage against the electrical fields generated in the transducer, which are only small in any case, which can be advantageous if liquid sensitive to electrical fields pumped. The bending body, for example made of stainless steel or aluminum, can also be coated with a layer of gold on its side forming the conveying surface if necessary.

The section 2144a of the piezoelectric element 2144 shown in FIG. 31 differs from the element section shown in FIG. 26 in that its polarization P or, more precisely, pre-polarization is parallel to the z-crystal axis and, in the undeformed idle state, is perpendicular to the intended conveying surface. If an electrical field E parallel to the polarization P acts on the element section 2144a from the outside, this changes its dimensions measured at right angles to the field direction and in particular its length measured parallel to the conveying direction, the conveying direction here being parallel to the x-crystal sacrifice. The change in length or elongation is then determined by the piezoelectric coefficient d _{3 1} . If the electric field E and the polarization according to Figure 31 are both the same

Direction and namely both are positive, positive results in an element consisting of lead zirconate titanate, i. H. an extension. If, on the other hand, the field is directed opposite to the polarization, there is accordingly a negative expansion, i. H. a shortening.

According to FIG. 32, the strip-shaped, piezoelectric element 2144, together with a likewise strip-shaped, non-piezoelectric bending body 2145 and electrodes 2147, can form a transducer 2143 and a bendable conveying element 2141. The bending body 2145 is delimited on its side facing away from the transducer by the conveying surface 2145a and, analogously to the bending body 2045, serves as contiguous over the entire length of the Transducer extending counter-electrode. The excitation electrodes 2147 on the side of the transducer 2143 facing away from the flexible body 2145 correspond to the electrodes 2047. When an element section 2143a is lengthened by the action of an electrical field, it causes the associated transducer section to bend in cooperation with the flexible body 2145 which maintains its length 2143a. Such converters are often referred to as monomorph converters.

As indicated by vertical arrows in the bottom partial diagram of FIG. 33, the first and second element sections 2144a can be positive, the third and fourth element sections negative, the fifth and sixth element sections positive again and the seventh and eighth element sections polarized again. If, in successive time intervals t ₁ , t ₂ , t ₃ , t _4, electric fields act on the element sections, the directions of which are indicated by the vertical arrows of the four upper partial diagrams of FIG. 33 and namely are the same as in the corresponding partial diagrams of FIG. 28 the shapes of the conveying surface 2145a drawn in the partial diagrams of FIG. 33, wave crests 2175 being formed. The shape of the conveying surfaces shown in FIG. 33 essentially differs from those in FIG. 28 essentially only in that they are shifted by a quarter wavelength in relation to one another in the time intervals corresponding in pairs in the two figures. The bends of the conveying surface 2145a can accordingly be formed by similar ones

Sequences of electrical signals are generated like the bend on the conveyor surface 2045a. Otherwise, the conveying member 2141 can be arranged in a pump body in the same or a similar way as the conveying member 2041. The strip-shaped conveying element 2241 shown in FIG. 34 has a transducer 2243 and a flexible body 2245 with a conveying surface 2245a. The transducer 2241 has two piezoelectric, strip-shaped elements 2251 and 2253. The strip 2251, which is farther from the flexible body 2245, is provided on its side facing away from the flexible body 2245 with a counter-electrode 2247 which extends continuously over its entire length and is formed by a thin, vapor-deposited metal layer. Furthermore, the two are piezoelectric

Elements 2251, 2253 are provided on their mutually facing sides with the excitation electrodes 2147 corresponding excitation electrodes 2255 and 2257, which likewise consist of thin, vapor-deposited metal layers, and are mechanically connected to one another via these. The flexible body 2245, which also serves as the counter electrode, and the counter electrode 2247 are connected to the ground connection of an electronic device corresponding to the electronic device 2061. The pair of excitation electrodes 2255, 2257 are electrically conductive to one another in pairs and are also connected to signal generators corresponding to signal generators 2065, 2067.

The sections 2251a and 2253a of the piezolectrical elements 2251 and 2253, which are assigned to one excitation electrode 2255 and 2257 and are located one above the other, have, in the undeformed state according to FIG. 35, polarizations P which are perpendicular to the conveying surface and if they are aligned to the two exciters, for example Electrodes 2255, 2257, which are located between two sections 2251a, 2253a arranged one above the other and an electrical voltage negative to ground are applied, act on the two sections of the piezoelectric elements according to FIG. As a result, one of the two element sections is lengthened and the other shortened so that the relevant area of the conveyor element bends, as illustrated in Figure 36. As a result of the opposite changes in length of the sections of the piezoelectric elements which are arranged one above the other and are mechanically connected to one another, the same dimensions of the piezoelectric elements and the same field strengths result in a greater bend than in the transducer shown in FIGS. 31 and 32. So that the bending body 2245 opposes this stronger bending as little resistance as possible, it is preferably substantially thinner than the piezoelectric elements and possibly the same as the electrodes 2247, 2255, 2257 only formed from a vapor-deposited metal layer. 2243 type transducers are often referred to as bimorph transducers or bilaminar transducers.

The conveyor member 2341 shown in FIGS. 37, 38, 39 has a converter with a first, thermal converter element 2343 and a second, thermal converter element 2345. The second transducer element 2345 forms the conveying surface 2345a which is flat in the idle state. The two layered and strip-shaped thermal transducer elements are connected to each other with their facing surfaces and consist of materials with different thermal expansion coefficients, namely metallic materials, such as iron-nickel alloys, as are available on the market for the formation of thermobimetal strips are. However, it would also be possible to manufacture at least one of the two thermal transducer elements and preferably at least the transducer element 2343 from a non-metallic, but nevertheless heat-conductive material, such as beryllium oxide ceramic or a special glass. The two thermal transducer elements 2343, 2345 thus together form a composite body, namely a thermobimate radial strips. There are also a number, namely four thermoelectric elements 2351, which are each formed by a semiconductor Peltier element. The four thermoelectric elements 2351 are distributed over the length of the thermal bimaterial strip and arranged alternately on different sides thereof. The opposite ends of each thermoelectric element 2351 are each conductively connected to a section of the first thermal transducer element 2343 by a heat conductor 2353, which consists, for example, of an angled and bent lug made of copper, the heat conductors at the connection points being connected by a heat-conducting but are electrically insulating, for example made of beryllium oxide ceramic 2355 electrically isolated from the thermal transducer element 2243. Apart from the two heat conductors located at the end of the thermal transducer element 2343, each of these is connected to the thermal transducer element 2243 between two other heat conductors, which belong to one or two other thermoelectric elements. The opposite ends of each thermoelectric element 2351 are connected by electrical conductors to an electronic device 2361, wherein one of the two connections of each thermoelectric element can be connected to the ground connection of the electronic device. The other connections can then be connected to signal generators corresponding to signal generators 2065, 2067. The conveying member 2341 can be assembled with other parts of a pump body, not shown, in such a way that, like the conveying member 2041, it limits a conveying passage together with a contact member.

When an electrical voltage is applied across the two electrical connections of a thermoelectric element 2351, the thermoelectric element operates to a certain extent as a heat pump and cools one section of the thermobimaterial strip connected to it via the one heat conductor, while it heats the section connected to it via the other heat conductor. The sign of the applied electrical voltage can be used to determine which section is cooled and which section is heated. By cooling and heating in places, it can be achieved that the thermobi material strip bends in a wave shape due to the different thermal expansion coefficients of the two layers forming it, the conveying surface 2345a, which is flat in the idle state, naturally also becoming wave-shaped. Furthermore, the shaft formed by the conveying surface can proceed in a step-by-step manner, for example in the case of the conveying element 2141, in which the movement is generated by changes in length from the piezoelectric transducer sections. With a suitable arrangement of the thermoelectric elements, the desired bends can be generated with analog electrical signal sequences, as is the case with the conveying elements 2041 and 2141. The conveying means 2341 in the conveying element 2341 are used to convert electrical excitation voltage signals into bends from the thermoelectric elements 2351 and one Conveyor belonging transducer formed, which consists of the thermal transducer elements 2343, 2345.

The conveyor element 2441 shown in FIG. 40, consisting of an annular strip, has an annular bending body 2445 with a conveyor surface 2445a that is flat in the idle state and perpendicular to the ring axis and radial. A piezoelectric transducer with, for example, sixteen electrodes 2447 distributed over its circumference is located under the flexible body. The transducer enables the conveying surface 2445a to be continuously operated during operation by shearing or length changes of transducer sections. to deform such that it forms a shaft enclosing the central axis of the conveyor element with four axially projecting wave crests. The shaft can advance in a step-like manner as in the case of the conveying bodies 2041, 2141, 2241.

The conveying member 2541 shown in FIG. 41 also consists of an annular strip and has a piezoelectric transducer 2543 and a bending body 2545 with a conveying surface 2545a, which in the idle state forms a cylindrical surface which is coaxial with the axis of the annular conveying member and thus in a cylinder surface placed through the ring axis Cut is flat. The transducer is provided with sixteen electrodes 2547 distributed over its circumference, so that the operating surface can be bent during operation by means of the transducer in such a way that it forms a shaft with four wave peaks distributed over the circumference, projecting radially and at right angles to the axis of the annular conveying member, the wave progressing suddenly. For ring-shaped conveying elements of the type shown in FIGS. 40 and 41, it is then natural to provide additional components which serve to form pump bodies and which, together with these conveying elements, form conveying passages. Conveying elements with annular conveying surfaces designed analogously to the conveying surfaces 2445a, 2545a can of course also be formed with transducer means which, analogously to the transducer means used to bend the conveying element 2341, have thermoelectric elements and a thermobi material strip.

In the pump shown in FIGS. 24 and 25, a contact element could also be provided on the lower side of the delivery element with a contact surface and seals facing the delivery element. Accordingly, the funding agency would be on the lower side of the converter 2043 also to be equipped with a flexible body which would then have to be insulated from the electrodes 2047. This would result in two funding rounds. The seals or any other, at least partially elastically deformable, closing means used to close the ends of the conveying passages and / or the fluid connections could then optionally be designed such that the two conveying passages are connected in parallel in terms of fluid or else allow separate delivery of fluids.

The pump shown in FIGS. 42 and 43 has a pump body 3001 with two elongated, strip-shaped delivery elements 3041, shown separately in FIG. 44, the sides of which face each other as

Conveying surfaces 3041a serve. Each of the two conveying members 3041 is essentially formed by a piezoelectric transducer 3043. This has eight transducer sections 3043a distributed uniformly over its length, the limits of which are shown in FIGS. 42 and 44 by dashed lines. The two conveying members 3041 are each fastened to a rubber-elastic support body 3035, for example made of silicone foam rubber, on their sides or surfaces facing away from one another. The two support bodies 3035 are connected to one another along the longitudinal edges of the two conveying members 3041 by rubber-elastic, strip or plate-shaped seals 3093. The two end faces of the cuboid pump body are formed by dimensionally stable, for example metallic or plastic, end plates 3095, which are tightly connected to the two support bodies 3035 and to the two plate-shaped seals 3093. The two supporting bodies 3091 made of foam rubber press the two conveying members 3041 resiliently against one another, so that they, with their entire conveying, in the flat resting state surfaces 3041a and, when operating with mutually facing wave crests formed by them, bear against one another.

The transducer sections 3043a extend to the longitudinal edges of the piezoelectric elements and have a rectangular or square outline in a plan view of the conveying surface.

The piezoelectric transducers 3043 are designed in such a way that they and their transducer sections during operation described in more detail by the electrical excitation voltages at least essentially only along a plane running in the longitudinal direction of the conveying members 3041 and at right angles to the conveying surfaces 3041a and therefore parallel to the sectional plane of FIG be deformed. The conveying members are therefore not deformed, or at least not strongly deformed, at right angles to this plane and have the same shape over their entire width in section planes parallel to the section plane of FIG. 42. The conveying passage 3077 formed during operation by piezoelectric deformation of the transducers and conveying members has eight pumping spaces 3079 distributed over its length, each of which is located between a pair of opposing transducer sections 3043a. The conveyor passage 3077 is sealed on both long sides by the plate-shaped seals 3093. The conveying passage through the end plates 3095 and their connection to the supporting bodies 3035 and the seals 3093 is completed at both ends. In this pump, the end means closing the delivery passage at its longitudinal edges and ends against the environment are formed by the seals 3093 or end plates 3095 in cooperation with the supporting bodies 3035. The support body 3035 and seals 3093 are incidentally deformable in this way and connected to one another and to the conveying members 3041 in such a way that they hamper their undulating deformations as little as possible and also enable the length changes of the conveying members resulting from these deformations. A fluid connection 3017 or 3019 or 1073 is present at each of the two ends of the conveying passage 3077, which, for example, penetrates the end plate 3095 in question and is connected to the pump chamber 3079 there at least when the latter is connected to the relevant one End plate 3095 is open. However, the fluid connections could instead be connected to said pumping spaces through holes in one of the supporting bodies and conveying members.

For example, the two piezoelectric transducers 3043 can be deformed by shearing analogously to the transducer 2043 and accordingly each have a piezoelectric, layer-shaped element. These two elements are provided on their mutually facing sides with counter-electrodes which extend coherently over the entire surface and on their other sides with an excitation electrode for each transducer section. The two piezoelectric elements are polarized in each region assigned to a transducer section in the longitudinal direction of the conveying passage 3077, and advantageously in such a way that two transducer sections with the same polarization are located next to one another along the conveying passage and then a pair of transducer sections with opposite each other Directed polarization follows. The sections of the two piezoelectric elements belonging to opposing transducer sections are polarized identically in pairs, for example. An electronic device, not shown, has a ground connection connected to the two counter electrodes and two excitation connections. If you turn the converter off cuts along the conveyor passage, for example, counting continuously from left to right, the exciter electrodes of the first, third, fifth and seventh transducer sections of the two piezoelectric elements are connected to one exciter connection and the remaining exciter electrodes to the other exciter connection of the electronic device. The electronic device can supply two excitation voltages to the excitation electrodes connected to its two excitation connections during operation, which have alternating positive and negative values over time and, for example, a rectangular shape. Each excitation voltage thus forms a sequence of alternating positive and negative excitation signals, namely rectangular pulses or, more precisely, rectangular half-pulses, which follow one another without any time gaps. The two excitation voltages are shifted from each other by a phase angle of 90 °.

During operation, the transducer sections are curved by shear forces in such a way that each of the two conveying surfaces 3041a forms bulges which alternately protrude along the conveying passage 3077 to different sides of the plane spanned by the respective conveying surface in the idle state. The two conveying surfaces then each form a wavy line in longitudinal section and lie against one another at the apexes of the mutually facing wave crests, as is shown in FIGS. 42 to 44 with a greatly exaggerated wave crest height. The waves formed by the two conveying surfaces are mirror-symmetrical to one another. In the case of the wave-like deformation of the conveying members, these or, more precisely, their areas not belonging to the adjacent crests of the crests are opposed to one another by the restoring forces caused by the two rubber-elastic supporting bodies 1091 the way pressed. Each conveyor element 3041 has four transducer sections per wavelength λ of the waves formed by the conveyor surfaces 3041a. At any point in time when one of the two excitation voltages changes sign, that is, after a quarter of the period of the excitation voltages, the waves formed by the conveying surfaces shift by a quarter of the wavelength along the conveying passage, for example from left to right. In the conveying passage 3077, cavities or cells progressing from left to right are formed, of which at least one or both ends in each cycle is delimited by a pair of adjacent Wellenberg apexes and contains four contiguous pumping spaces 3079. The individual pumping spaces 3079 thus change their volume step by step, with this having a non-zero value in each cycle taking place during operation. When the pump is operating, a fluid can therefore be conveyed peristaltically from the fluid connection 3017 through the delivery passage to the fluid connection 3019.

Of course, the sections of the two piezoelectric elements belonging to the different transducer sections do not necessarily have to have the specified polarization directions and could, for example, all be polarized in the same direction. The design of the electronic device and its connection to the excitation electrodes would then have to be adapted accordingly. In addition, the transducers 3043 could be designed as monomorph or bimorph transducers instead of being deformable by shearing.

The pump shown in FIGS. 45 and 46 has a cuboid pump body 3101 with two strip-shaped delivery members 3141. Every funding body consists at least essentially of a transducer 4143. Each of the two transducers 4143, which together form the transducer means of the pump, has a strip-shaped inner piezoelectric element 3151 that extends coherently over its entire length and width. The piezoelectric elements 3151 of the two transducers are each provided on their mutually facing sides with a counter-electrode 3145 which extends coherently over their entire length and width. The mutually facing sides of these counter electrodes each form a conveying surface 3145a. On the side of each piezoelectric element 3151 facing away from the conveying surface 3145a, two strip-shaped, narrower, outer piezoelectric elements 3153 are arranged, which are likewise connected over the entire length of the conveying member 3141 and

Extend converter 3143. However, the widths of the elements 3153 are a little smaller than half the width of the element 3151. The two elements 3153 belonging to the same transducer are arranged next to one another in such a way that their outer longitudinal edges are flush with one longitudinal edge of the element 3151. There is then a narrow space between the mutually facing longitudinal edges of the two elements 3153. The piezoelectric element 3151 of each transducer 3143 is on its side facing away from the counter electrode 3145 evenly over its side

Distributed in length, provided by narrow spaces between excitation electrodes 3155. Each piezoelectric element 3153 is provided on its side facing element 3151 with eight exciter electrodes 3157 distributed over its length and separated from one another by gaps, each of which rests on an exciter electrode 3155 and is mechanically and electrically connected to it. Each element 3153 is also on its side facing away from element 3151 with a cohesive extending over its entire length Provide counter electrode 3147. The two conveying members 3141 are held by a one-piece rubber-elastic supporting body 3135, which completely encloses them both in cross section and in longitudinal section. For example, the support body consists of a silicone rubber that has a few closed pores in order to allow small changes in volume when deformed. However, only fewer pores need to be present than are usually present with conventional foam rubbers. The support body is provided at both ends of the conveying members 3141, which rest against one another in the idle state, with a fluid connection 3117 or 3119, which has a blind hole opening into the transversely to the conveying members and parallel to their conveying surfaces from a longitudinal side of the supporting body 3135, which at least approximately over the whole

Width of the two funding bodies extends. The support body 3135 can be formed in the manufacture of the pump by encapsulating the two conveying members 3141 with a silicone rubber compound. When projected onto the plane running between their conveying surfaces, the two conveying members generally have a rectangular outline. However, each of the two conveying members is provided with a bevel shown in FIG. 47 at one of the corners. The support body 3135 can still be attached to a non-illustrated, dimensionally stable support and / or enclosed by a dimensionally stable housing. Figures 45, 46 are - similar to various previous figures - not drawn to scale, but with greatly exaggerated thicknesses of the piezoelectric elements and electrodes and also with exaggerated heights of the waves formed by the conveying surfaces during operation. The piezoelectric elements 3151, 3153 are in reality, for example, 32 mm long, 9 mm or 4 mm wide and - measured at right angles to the conveying surfaces - 0.15 mm to 0.3 mm thick. The thicknesses of the electrodes can, for example, be on the order of 0.001 mm. The pump also includes an electronic device 3161, shown in FIG. 47, with, for example, generator means having a microprocessor for generating electrical excitation voltages. The counter-electrodes 3145, 3147 connected along the entire length of the transducers are electrically connected to the ground connection by connecting lines and the excitation electrodes 3155, 3157 are connected to two excitation connections or signal outputs of the electronic device 3161 by connecting lines. The sections of the electrical connecting lines adjoining the various electrodes are led out of the support body 3035 through regions thereof. The two counter-electrodes 3145 are connected at that corner to a connecting line in which the other transducer has the aforementioned bevel. The counter electrodes 3147 can be connected to connecting lines at any edge points. Connection lines are connected to the excitation electrodes 3155, 3157, each of which leads out of the support body between a pair of piezoelectric elements 3153 located next to one another. This type of connection of the electrodes enables the conveyor passage 3177 which arises during operation between the two conveying surfaces 3145a to be sealed off from the environment practically without hindrance by the connecting lines along all edges of the conveying surface by means of the elastically deformable closure means formed from the supporting body. In each converter 3143, the electrodes 3155, 3157 define eight converter sections 3143a distributed over the length of the converter.

The piezoelectric elements 3151, 3153 of the transducers 3143 designed as a bimorph transducer are polarized analogously to the piezoelectric elements 2251, 2253 of the transducer 2243. The directions of polarization of the portions of the piezoelectric elements 3151, 3153 belonging to the various transducer portions 4143a are schematically represented by arrows in Figure 48. Otherwise, the electrodes are connected to the electronic device in a manner analogous to that of the converters 2043, 2143, 2243. The generator means of the electronic device 3161 generate two periodic alternating excitation voltages. The instantaneous voltage values U of these excitation voltages as a function of time t are shown in FIG. 49 by the two lines 3191 and 3193. The excitation voltages generated by the electronic device 3161 have identical positive and negative, half-wave signals and are out of phase with one another like the excitation voltages represented by lines 2091 and 2093 in FIG. 30, but differ from them in that their temporal changes everywhere are steady. Lines 3191 and 3193 can have straight sections at zero crossings, slopes inclined with respect to the time axis, and curved sections at the positive and negative maximum values. The times t are also shown in FIG. 49. ₁ , t ₂ , t ₃ , t ₄ , which correspond to the corresponding times in FIGS. 28, 30 and 33.

When the excitation voltages are supplied to the electrodes of the transducers 3143, the portions of the piezoelectric elements 3151, 3153 belonging to the same transducer portion 3143a change their lengths in opposite directions. As a result, the two conveying members 3141 can be bent in a wave-like manner, as was explained for the conveying member 2241. When pumping a fluid, the two conveying surfaces 3145a then form waves in a section running along the conveying direction, analogously to the conveying surfaces 3041a of the conveying members 3041, which are mirror-symmetrical to one another with respect to the plane running between the two conveying surfaces. The waves formed by the conveying surfaces 3145a can be stepped or jumped by a quarter each Wavelength are shifted, as has been explained with reference to Figures 28 and 33 for the conveyor surfaces 2045a and 2145a. If the excitation voltages according to lines 3191, 3193 change continuously over time and the signals formed by half waves of the excitation voltages have inclined flanks, the shapes of the conveying surfaces are also continuously changed in a precisely defined manner. It can thereby be achieved that the volume of a cell, which is located between two adjacent contact points of the two conveying surfaces 3145a in FIG. 45, remains exactly constant even during the displacement of the wave crests by a quarter of the wavelength. The rubber-elastic support body 3135 presses the two conveying elements resiliently against one another both when the conveying surfaces are at rest and when they are deformed in a wave shape. Furthermore, the support body can also deform in the longitudinal direction of the conveying passage 3177, ie shorten and lengthen, and thus adapt to the changes in the lengths of the conveying surfaces measured parallel to the plane running between the two conveying surfaces when deforming them. The heights of the shafts formed by the two conveying surfaces during operation can vary from 0.004 mm to 0.04, depending on the length of the piezoelectric elements and a width of the piezoelectric elements and a thickness of 0.2 mm, depending on the magnitude of the electrical voltages supplied mm and, for example, at voltages with an amplitude of 30 V each about 0.01 mm.

The pump shown in FIG. 50 has a pump body designated as a whole by 5001. This is formed from a dimensionally stable, flat, platelet-shaped, elongated carrier serving as contact element 5003 with a rectangular outline and a contour arranged on one side of contact element 5003, which has the same contour as this and thus completely covers, plate-shaped or foil-shaped conveying element 5004, which in FIG the undeformed state of rest shown in FIG. 50 is also flat.

The conveying element 5004 is provided with transducer means and namely consists at least essentially of a piezoelectric transducer 5005. This has two layer-shaped, for example equally thick, elastically deformable elements 5007, 5009 made of dielectric, piezoelectric material. Each of the two piezoelectric elements 5007, 5009 is formed, for example, exclusively by a compact, coherent layer made of piezoelectric ceramic, such as lead zirconate titanate, or by a "composite" material which comprises a plastic mass or matrix and particles embedded therein made of piezoelectric ceramic. The transducer is also provided with various electrodes, which include a plurality of exciter electrodes 5011, 5013, 5015, 5017, which are arranged between the two piezoelectric elements 5007 and 5009 and are distributed over the length of the transducer, second, third or fourth excitation electrode. As can be seen in FIG. 51, the four excitation electrodes have centers lying on the longitudinal symmetry line or plane of the transducer and generally have a circular outline with the diameter d. The distance a between the centers of adjacent excitation electrodes is at most or approximately equal to the circle diameter d and preferably a little, for example about 5 to 20%, smaller than this. In other words, the enveloping circles of the adjacent excitation electrodes should touch at least approximately and, for example, overlap a little. The generally circular outline or edges of the excitation electrodes 5011, 5013, 5015, 5017 are flattened a little on their sides facing each other in pairs, ie provided with sections formed from straight circular chords, so that narrow spaces between the adjacent exciters -Electrodes present and the latter are electrically isolated from one another. In addition, at least one of the excitation electrodes and, for example, each of these, may have a recess, which is small compared to its surface and consists of a slot-shaped incision, in which a first space separated from the excitation electrode by a narrow space and thus electrically insulated from it or second or third or fourth detector electrode 5021 or 5023 or 5025 or 5027. On the side of the piezoelectric element 5007 which is closer to the contact element 5003 and is closer to it, there is a counter-electrode 5031 which extends coherently over its entire length. On the side of the piezoelectric element 5009 which is further away from the contact element, there is also a counter-electrode 5033 which extends coherently over its entire length. The two piezoelectric elements and the different electrodes are firmly connected to each other with their surfaces facing each other in pairs. Since the transducer 5005 has two piezoelectric, expandable elements 5007, 5009 in addition to the different electrodes, it forms - like the transducers 2243, 3143 described above - a bimorph transducer or bilaminar transducer.

The edge of the conveyor element 5004 and piezoelectric transducer 5005 or, more precisely, its edge zone located in the projection shown in FIG. 51 and outside of the four excitation electrodes and enclosing this edge zone is solid and fluid-tight along the entire rectangular outline of the conveyor element connected to the edge or the edge zone of the contact element 5003, for example welded and / or glued. The edges of the contact member 5003 and conveyor member 5004, which are surrounded and welded by the welded and / or glued edges, face one another

Surfaces of these organs 5003 and 5004 form a stable shape Contact and / or counter surface 5035 or a deformable conveying surface 5037.

As already mentioned in the figure legend, the figure 50 - like other figures - is not drawn to scale. It should be noted here that the elements 5007, 5009 are drawn with exaggerated thicknesses in FIG. 50 compared to the length and width of the transducer 5005 and to the outline dimensions of the excitation electrodes 5011, 5013, 5015, 5017. This applies to an even greater extent to the electrodes consisting, for example, of vapor-deposited metal layers. The thicknesses of the two piezoelectric elements 5007 and 5009 are, for example, in reality approximately 10 to 100 times and the thicknesses of the various electrodes are approximately 100 to 1000 times smaller than the diameter d of the excitation electrodes, for example 5 to 15 mm, or, more precisely , the enveloping circles of the excitation electrodes.

Each of the four excitation electrodes 5011, 5013, 5015, 5017 defines a portion of the piezoelectric transducer. These four sections are referred to below as first or second or third and fourth piezoelectric transducer sections 5041 or 5043 or 5045 or 5047. The edges or boundaries of the four transducer sections coincide at least substantially with the generally circular edges or contours of the four excitation electrodes, it being assumed that the transducer section edges or boundaries of the mutually adjacent transducer sections lie between the respective ones Touch transducer sections and are therefore formed there by the circular chords, at the end points of which the enveloping circles of the excitation electrodes intersect. In FIG. 50, the boundaries of the converter sections are indicated by dashed lines. If the converter 5005 is in its idle state shown in FIG. 50, its conveying surface 5037 facing the contact element 5003 and formed by the excitation electrode 5031 is completely flat and is at least somewhat fluid-tight or at least at least somewhat and possibly completely liquid-tight on the one facing it , flat contact and / or counter surface 5035 of the contact element 5003. As will be explained in more detail with reference to FIGS. 52 to 58, however, each of the four transducer sections 5041, 5043, 5045, 5047 can be selected individually or together with at least one against an elastic restoring force by means of external electrical fields acting on its piezoelectric elements 5007 and 5009 adjacent transducer section are domed away from the contact member 5003. Between the contact and / or counter surface 5035 and the section of the conveying surface 5037 belonging to a specific transducer section, when the transducer section bulges, a cavity results, the volume of which lies between a value that is at least practically zero and a finite value determined by the maximum curvature of the transducer section is changeable. By arching the conversion sections, a delivery passage 5049 for the fluid to be pumped can be formed between the two surfaces 5035 and 5037. The between that

The contact element and the cavities that can be generated in the first, second, third, and fourth transducer sections are referred to below as first pump chamber 5051, second pump chamber 5053, third pump chamber 5055, and fourth pump chamber 5057. The pump is provided with two fluid connections 5071 and 5073, which penetrate the contact element 5003 and into the area of the contact and / or counter surface 5037 covered by the first converter section 5041 and the fourth converter section 5047 and thus into the first and fourth pump chamber 5051 and 5057 respectively.

An electronic device also belongs to the pump 5081, which is connected by electrical conductors to the four excitation electrodes 5011, 5013, 5015, 5017, the four detector electrodes 5021, 5023, 5025, 5027 and the two counter electrodes 5031, 5033. The latter two are connected to one another and connected to the ground connection of the electronic device. The four excitation electrodes are each connected to an excitation connection or signal output and the four detector electrodes are each connected to a detector connection of the electronic device. The electronic device 5081 is connected to a supply voltage source 5083, which is formed, for example, by at least one battery and which supplies or each electrical voltage required for the operation of the electronic device and the entire pump. The electronic device 5081 and the or each battery of the supply voltage source 5083 are preferably fastened to the carrier forming the contact element 5003.

Now a few terms are to be defined first. The central surface of the piezoelectric transducer 5005 is understood below to mean that surface which runs parallel to the conveying surface 5037 through the center of the piezoelectric transducer. The same applies to the central surface of the archable transducer sections. The middle surfaces of the piezoelectric elements 5007 and 5009 are accordingly understood to mean the surfaces parallel to the conveying surface 5037 through the center of the piezoelectric elements 5007 and 5009.

The first converter section 5041 can be seen particularly clearly in FIGS. 52 and 53. In these two figures, an axis 5061 is drawn, which runs at right angles to the contact and / or counter surface 5035 formed by the contact element through the center of the first excitation electrode 5011 and thus the central axis of the first Converter section 5041 forms. Furthermore, in the two FIGS. 52, 53, two edge points of the first transducer section 5041 which are located on opposite sides of the axis 5061 and are symmetrical with respect thereto, or more precisely, surface lines of the lateral surface forming the transducer section boundaries are indicated by dashed lines. In FIG. 52, which shows the transducer section 5041 in the undeformed, flat rest state, b and c denote the distances from the two edge points from one another measured along the central surface of the elements 5009 and 5007, respectively. The distances b and c in the undeformed transducer are equal to the diameter d of the transducer section 5041 or, since this is not completely circular, equal to the diameter of the enveloping circle of the transducer section.

The two elements 5007 and 5009, consisting of piezoelectric, ceramic material, for example lead zirconate titanate, are polarized during the manufacture of the transducer with an electric field, at least in the region of the transducers, or, more precisely, pre-polarized such that the pre-polarization or in short, polarization P is perpendicular to the conveying surface 5031. The polarization P is shown in FIGS. 52 and 53 for the first converter section 5041 by arrows or vectors. The polarization P arises from the fact that during pre-polarization the z-axis or third axis of the lead-zirconate-titanate domains belonging to the hexagonal crystal system is directed at right angles to the conveying surface 5037. The x-axis or first axis of the domains can then be directed, for example, parallel to the longitudinal direction of the transducer, the x- and y-axes in the hexagonal crystal system being equivalent in terms of the piezoelectric behavior. The sections of the same converter section 5041 The two elements 5007 and 5009 have opposite polarizations, the polarization P of the lower element 5007, for example, directed downwards and negative and the polarization P of the upper element 5009 directed upwards and positive. For the rest, the element 5007 is polarized identically in all the sections belonging to the different converter sections 5041, 5043, 5045, 5047. The same applies to element 5009.

If a reference mass, that is to say positive with respect to the two counter electrodes 5031, 5033, is applied to one of the excitation electrodes, for example to the first excitation electrode 5011, this generates from the outside onto the sections belonging to the first converter section 5041 of the two piezoelectric elements 5007 and 5009 acting, illustrated in FIG. 53 by arrows or vectors, the two external electrical fields E are directed in both elements 5007, 5009 in the same way as the polarizations P present in them. In the area of the first transducer section 5041, the electric fields E cause strains of the two piezoelectric elements 5007 and 5009 in all directions perpendicular to the polarization P and to the electric fields E themselves and therefore in all directions that are flat to the one spanned by the transducer in the undeformed idle state Surface, ie the conveyor surface 5037 are parallel. Since the electric fields E have the same direction as the polarization P, the strains caused by them are positive. In other words, the dimensions of the layer sections under the influence of the fields are enlarged in all directions parallel to the conveying surface. Otherwise, the fields cause a contraction of the layers parallel to the field direction, but in this case is irrelevant. The magnitudes of the strains resulting in the two piezoelectric elements 5007 and 5009 as a result of the field are proportional to the piezoelectric coefficient d _{3 1} of the material forming the layer in question and also to the electric field strength acting on the layer in question. In the present case, the said piezoelectric coefficients are greater for the material forming the upper element, ie element 5009 further away from the contact element 5003, than for the material forming the other element 5007. If the two elements 5007 and 5009 have the same thickness, the absolute values of the field strengths of the electric fields generated by the same electrical excitation voltage in the two elements 5007 and 5009 become the same. The element 5009 is then stretched or elongated more than the element 5007. As a result, the transducer section 5041 bulges in a dome-shaped manner under an elastic deformation such that the section of the conveying surface 5037 belonging to it protrudes from the contact element 5003 (not shown in FIGS. 52 and 53) stands out above. The height of the curvature of the conveying surface section belonging to the transducer is drawn in FIG. 53 as well as in FIGS. 54 to 58 with an exaggerated size in comparison with the diameter of the transducer section enveloping circle and is dependent on an approximately 5 to 15 mm diameter of the transducer section enveloping circle of the thicknesses of the piezoelectric elements 5007, 5009, the values of the piezoelectric coefficients and the field strengths of the electrical fields, for example in the size range from 0.0002 to 0.02 mm. The distances of the two diametrically opposed edge points of the transducer section 5041 measured along the central surfaces of the elements 5009 and 5007 have the values denoted by b 'and c' in FIG. 53 in the curved transducer section 41. The one at the middle surface of the transducer 5005 and the first transducer section 5041 perpendicular to the axis 5061 measured diameter or, more precisely, the envelope diameter of the transducer section 5041 has the value d 'in the curved transducer section.

If one assumes in a thought experiment that the transducer section 5041 has been cut out of the transducer and would be bulged, for example, by external forces acting on it in such a way that its central surface maintains its length and forms the so-called neutral fiber, this would be the central surface of the transducer section measured diameter when bulging relatively sharply shortened. Accordingly, d 'would be considerably smaller than d. If one now further assumes in the thought experiment that the transducer section 5041, as is actually the case, is connected at its edge to the rest of the transducer, the reduction in the diameter of the transducer section which arises when the transducer section is arched would be in the edge region of the transducer section and into the latter adjacent areas of the transducer cause relatively strong mechanical stress that inhibit the bulging.

In the piezoelectric transducer actually used, both the upper and the lower piezoelectric element are stretched, ie lengthened, parallel to the conveying surface in order to bulge the transducer section, as described. It can thereby be achieved that when bulging, the two elements 5007 and 5009 and thus also the central surface of the entire transducer section are extended so much that the diameter of the transducer section changes less than if only the dimensions of one of the two elements 5007 were used for bulging. 5009 changed or the dimensions of the two elements would even be changed in opposite directions. If the piezoelectric Coefficients and the values of the electric fields E are suitably determined and coordinated with one another, it can even be achieved that the diameter of the transducer section in the arches resulting during operation, at least approximately, even if the transducer section is thought to be cut out of the transducer again and preferably remains exactly constant and, accordingly, d 'is at least approximately or exactly equal to d.

As already explained, the expansion of a layer-shaped element 5007, 5009 which results as a result of an external electrical field is dependent not only on the piezoelectric coefficients of the materials forming the elements, but also on the electrical field strengths. In order to keep the diameter of the transducers constant when bulging, instead of forming the two elements 5007, 5009 from materials having different piezoelectric coefficients, or in addition to this, provision could be made for fields with different field strengths to act on the two elements. Since the electric field strength is reciprocal to the distance between the electrodes producing the field, the two layer-like elements could be made of different thicknesses for this purpose. Instead, one could, for example, polarize both layer-shaped, piezoelectric elements 5007, 5009 to the same extent and form them of the same thickness, and supply the counter-electrode 5033 with a voltage which changes over time and whose maximum value measured against mass is equal in magnitude to the maximum values of the excitation electrodes 5011 , 5013, 5015, 5017 supplied voltages, but has an opposite sign. This then also enables fields with different field strengths to be generated in the two piezoelectric elements 5007 and 5009. After various variants have already been described above, which make it possible to keep the diameter of the converter section at least reasonably or exactly constant when it bulges, the pump designed according to FIGS. 50 to 53 and its operation will now be described further. The first case to be considered is that at a certain point in time only a single transducer section of the piezoelectric transducer 5005 is bulged by supplying an electrical voltage to the excitation electrode of the transducer section in question, or that at least no other transducer section immediately adjacent to this transducer section is bulged. Although the excitation electrodes 5011, 5013, 5015 and 5017 are not completely circular, the individually arched transducer section, for example the first transducer section 5041, has a tendency, due to the balancing of the mechanical stresses therein, at least approximately and practically to its axis 5061 to form a completely rotationally symmetrical shell or dome, which is at least approximately spherical cap-shaped. The edge zone of the piezoelectric transducer 5005 welded or glued to the contact element 5003 naturally retains its position when the first transducer section 5041 is arched. The same also applies, at least in the ideal case, to those areas of the deformable conveying surface 5037 of the transducer 5005 which are not firmly connected to the contact element and which do not belong to the curved transducer section 5041. An exception to this, however, is that segment of the enveloping circle of the first excitation electrode 5011 that overlaps the second converter section 5043 and thus, to a certain extent, belongs to both converter sections. If, therefore, only a single transducer section is arched, there is a region of the piezoelectric element that surrounds it more or less directly along the edge of the transducer section Transducer 5005 continues to be connected to contact element 5003 and closes off the pump space delimited by the latter and the bulged transducer section at least essentially in a liquid-tight manner against the other pumping spaces. For clarification, it should also be noted that this consideration neglects that because of the preferably existing overlap of the enveloping circles of the mutually adjacent transducer sections, the enveloping circles of the adjacent pumping spaces can also overlap a little, so that the cavity covered by a single, bulging transducer section may under certain circumstances also includes at least one area that actually already belongs to the immediately adjacent pump room.

If the surface areas of the contact element 5003, for example made of metal or a plastic, and the metallic counterelectrode 5031 lying freely on one another do not provide sufficient sealing, there would also be the possibility of designing the contact element 5003 and the conveying element 5004 in such a way that the two surfaces 5035, 5037 are in contact with one another with a certain elastic compressive force when the converter sections are at rest. Furthermore, the side or surface of the dimensionally stable contact element 5003 forming the contact and / or counter surface 5035 or that

The side of the counter-electrode 5031 forming the conveying surface 5037 can also be provided with a somewhat flexible and slightly elastically deformable coating, for example consisting of a soft plastic. However, this would of course still have to be so hard that it does not fill in the cavities, ie pumping spaces, created when the transducers are arched between them and the contact element 5003. In addition, the excitation electrodes of the converter sections that cannot be bulged under a certain operating state could possibly have a negative electrical one Voltage are supplied. The relevant converter sections would then have the tendency to bulge towards the contact element 5003 and would thereby be pressed against it.

The fluid connection 5071 is intended to serve as the inlet of the pump and can be connected, for example, to a fluid reservoir which can be fastened to the contact element 5003 and which contains a liquid medicament or a medicament consisting of a suspension. The fluid connection 5073 forms the outlet of the pump and can, for example, be connected to a cannula which is inserted into a body tissue of a living human or animal to which the medicament is to be supplied continuously or intermittently.

FIGS. 54 to 58 schematically show a chronological sequence of deformations used for the gradual, peristaltic delivery of the fluid to be pumped. It is assumed that before the start of the pumping process, all excitation electrodes 5011, 5013, 5015, 5017 are de-energized and the converter has the shape shown in FIG. 50. At the start of pumping, the first and fourth excitation electrodes 5011 and 5017 are exposed for a time interval with the duration t. a positive electrical voltage is supplied, as a result of which the first and fourth transducer sections 5041 and 5047 are elastically deformed and arched upward away from the contact element, so that they assume the shape shown in FIG. 54. When the first and fourth transducer sections bulge, the first and fourth pumping spaces 5051 and 5057 change their volumes from practically zero to their maximum value, as a result of which fluid is sucked from the reservoir through the fluid connection 5071 into the first pumping space 5051, as shown in the figure 54 is indicated by an arrow. After the time interval t ₁ , the voltage supply to the fourth excitation electrode 5017 is terminated and an electrical voltage is supplied to the second excitation electrode 5013, the electrical voltage applied to the first excitation electrode being retained. The fourth transducer section 5047 therefore deforms again into its flat rest position as a result of the elastic restoring forces effective in it, while at the same time the second transducer section 5013 is bulged. The first transducer section 5041 and the second transducer section 5043 now form a spatially curved elevation, shown schematically in FIG. 55, with the shape of an elongated dome, the edge of which lies against the contact member 5003 along its entire circumference. In a projection perpendicular to the plane spanned by the contact element 5003, the bulge formed by the two transducer sections 5041, 5043 has an oval-like outline shape, the oval in the connection area of the two transducer sections 5041, 5043 possibly having a flattening or even a small constriction. If the converter 5051 takes approximately the form shown in FIG. 55, the second pump chamber 5053 is also "opened" and then forms a coherent cavity together with the already existing first pump chamber 5051. If the piezoelectric element assumes the shape shown in FIG. 55, starting from its shape shown in FIG. 54, fluid flows from the first into the second pump chamber, with additional fluid flowing in through the fluid connection 5071 at the same time.

After a time interval with the duration t ₂ , the electrical voltages supplied to the excitation electrodes are changed such that the second converter section 5043 and the third converter section 5045 are bulged and the other two converter sections on the contact element 5003 apply, as illustrated in Figure 56. In this state, which extends over a time interval t ₃ , the fluid previously sucked in through the connection 5071 is in the second and third pumping chambers 5053 and 5055. The first and fourth pumping chambers 5051 and 5057 have the volume zero in this state of the converter. Accordingly, the first converter section 5041 closes off the fluid connection 5071 opening into the first pumping chamber 5051 and the fourth converter section 5047 closes off the fluid connection 5073 opening out into the fourth pumping room 5057.

After the time interval t ₃ , the transducer assumes approximately the form shown in FIG. 57 during a time interval with the duration t ₄ , in which the first and second transducer sections 5041 and 5043 abut the contact element 5003 and the third and fourth transducer sections are bulged. The sucked-in fluid is now in the two pumping spaces 5055 and 5057, of which the fourth pumping space 5057 is connected to the fluid connection 5073 serving as a fluid outlet.

When the time interval t _{4 has} elapsed, the third transducer 5045 resumes its rest shape, while the first transducer section 5041 bulges. The converter 5005 thus comes into the form shown in FIG. 58, which is identical to the form of the converter shown in FIG. 54. When the converter changes from the shape shown in FIG. 57 to the shape according to FIG. 58, the volume of the third pumping space is reduced to zero, so that part of the fluid previously present in the cavity formed by the two connected pumping spaces 5055 and 5057 passes through the fluid connection 5073 is pressed out. Fresh fluid is also simultaneously sucked in through the fluid connection 5071. At the next work cycle, the piezoelectric element again assumes the shape shown in FIG. 55. With this change in shape, the volume of the fourth pumping space also disappears, so that the rest of the previously sucked-in fluid is pressed out through the fluid connection 5073.

The shape changes of the piezoelectric transducer can now be continued cyclically, with a full cycle of four clocks, i.e. from four different

Combinations of converter sections which are in the idle state and are curved away from the carrier. There are two converter sections in the idle state and two in the bulged state in each cycle. In addition, in each cycle it has two immediately adjacent converter sections that are in the idle state and / or two immediately adjacent converter sections that are bulged. If one connects the two ends of the pump body with one another in thought, so that a closed path is created, the sequence of movements can be understood as the progression of two adjacent bulges along this path.

To generate these periodically and cyclically changing deformations of the four converter sections, the electronic device 5081 performs a first excitation voltage U ₁ or a second excitation voltage U ₂ or a third excitation voltage U ₃ or ₃ when the pump of the first, second, third and fourth excitation electrode is operating a fourth excitation voltage U ₄ . The diagram drawn in FIG. 59 shows a possible course of the four excitation voltages U ₁ , U ₂ , U ₃ , and U ₄ as a function of time t. Each of the four excitation voltages consists of a sequence of excitation signals, namely square-wave pulses, and alternately has the value zero and a positive one Maximum value that is the same for all four excitation voltages. The period of the four pulse sequences is equal to the sum of the four time intervals t ₁ , t ₂ , t ₃ , and t ₄ , which all have the same duration. The duration of each excitation signal is accordingly equal to the sum of the duration of two of the four time intervals t ₁ , t ₂ , t ₃ , t ₄ and thus equal to half the period. The excitation signals or pulses of the excitation voltages supplied to the excitation electrodes 5011, 5013, 5015, 5017, which are adjacent to one another in pairs, are shifted relative to one another in pairs by a phase angle of 90 °. The excitation voltage U ₃ is accordingly shifted by a phase angle of 180 ° relative to the excitation voltage U ₁ and thus symmetrical or inverse to the mean voltage value. Likewise, the excitation voltage U ₄ is 180 ° out of phase with the excitation voltage U ₂ .

The electronic device 5081 can have generator means for generating the four excitation voltages U ₁ , U ₂ , U ₃ and U ₄ , for example an excitation signal generator, namely a pulse generator for generating the excitation signal sequence forming the first excitation voltage U ₁ and a 90 ° phase shifter deriving and / or generating an excitation voltage U ₂ phase-shifted by 90 ° from the first excitation voltage U ₁ . The electronic device 5081 can furthermore have two voltage inverters or 180 ° phase shifters, in order to invert from the excitation voltages U ₁ , U ₂ by converting the maximum value of the voltage U ₁ to zero and vice versa, or by a 180 ° phase shift To generate excitation voltages U ₃ and U ₄ . Of course, the electronic device 5081 can also be equipped with differently designed circuit means for generating the four excitation voltages and can have, for example, a clock signal generator generating a clock signal sequence and its frequency is four times greater than the frequency of the four excitation voltages. The latter could then be generated by frequency division of the clock signal sequence. Furthermore, the electronic device for generating the excitation voltages can have a microprocessor, which of course is also provided and / or connected with a clock signal generator and can also perform control and / or regulating functions in addition to the generation of the excitation voltages.

The four excitation voltages consisting of square-wave pulses can also be replaced by pulse trains with trapezoidal or triangular pulses or by continuously changing voltages. The latter can then, for example, have a time profile similar to that of the excitation voltages represented by lines 9191 and 9193 in FIG. 49, but continuously have the same sign, that is to say instead of positive and negative half-waves, they have half-wave-shaped signal sections which alternate in the voltage / time diagram lie above and below a straight medium-voltage line that runs parallel to the time axis at half the peak value of the excitation voltage. The upper and lower half-wave-shaped signal sections, if one mentally shifts them by a phase angle of 180 ° relative to one another, are mirror-symmetrical to one another with respect to the medium-voltage line mentioned. The individual signal sections are also mirror-symmetrical to a line of symmetry running at right angles to the time axis through their apex. With such constantly changing excitation voltages, it can be achieved that the fluid-containing cell progressing along the conveying passage has exactly the same volume at all times and the fluid is conveyed even more uniformly than when driving with rectangular pulses. If the transducer sections 5041, 5043, 5045 and 5047 are deformed during operation of the pump, that is to say they are bulged alternately by the action of electrical fields and are deformed back into their rest shape by the elastic restoring forces effective in them, the piezoelectric elements 5007 and 5009 generate between them two counter electrodes 5031, 5033 and the four detector electrodes 5021, 5023, 5025, 5027 electrical potential differences. When the pump is in operation, electrical detector signals, ie voltage pulses, therefore pass from the detector electrodes to the electronic device 5081. The latter is provided with monitoring and / or control circuit means, which have, for example, at least one voltage comparator, which operate analog or digital and in the latter case can be formed, for example, by the microprocessor already mentioned, if any. The monitoring and / or regulating circuit means can furthermore have an optical and / or acoustic fault display device and be designed to check whether detector signals with the intended minimum voltage values arrive during operation of the pump, and otherwise by a flashing light and / or a buzzer sound or the like To signal malfunction. The monitoring and / or control circuit means can also have an analog and / or digital working controller, possibly formed at least in part by the microprocessor, if any, around the generator means serving to generate the excitation voltages, for example the excitation signal or clock signal generator or to regulate at least one controllable amplifier serving to amplify the excitation voltages and thus to regulate the maximum values, ie signal levels, of the excitation voltages in such a way that the detector signals and thus the bulge heights of the transducer sections have variables provided. As already mentioned, the conveyor element 5004, which is at least essentially formed by the transducer 5005, is firmly connected to the contact element at its edge zones. The dimensional stability and elasticity of the transducer, and in particular of its two piezoelectric elements, endeavor to keep the conveying member in its resting position and to press the deformable conveying surface resiliently against the contact surface when the archable transducer sections bulge. As already mentioned, the transducer can also be pre-tensioned in such a way that the conveying surface is pressed against the contact surface by a certain spring and / or pressure force when the pump is not in operation. 5017 are de-energized, the entire conveying surface 5037 of the piezoelectric transducer 5005 is therefore parallel to the contact and / or counter surface 5035 of the contact element 5003 and bears against it. The pump then shuts off the fluid connection between the two fluid connections 5071 and 5073 at least approximately completely tightly and in practice sufficiently tightly. It can also be seen from FIGS. 54 to 58 that the two fluid connections 5071 and 5073 in each state or cycle shown in these figures are fluidly separated from one another by two transducer sections lying on the contact element 5003. In this regard, however, it should also be noted that a liquid to be pumped, contained in a specific pumping chamber, resists a reduction in the volume of the pumping chamber concerned that occurs at the end of one of the time intervals t ₁ , t ₂ , t ₃ , t ₄ . When changing between the states shown in FIGS. 54 to 58, transitional states may therefore occur for a short time, in which three transducer sections are lifted off the contact element to a greater or lesser extent. Apart from the fact that this is done when the perio The duration, at most, during a small fraction of this, there is always at least one transducer section on the contact element even during such transition states that may occur. The pump thus separates the two fluid connections from one another in every state that occurs during pumping, so that a fluid backflow opposite to the intended delivery direction can never take place.

If the pump is used to deliver a medicament into the body of a human patient or animal, it can be advantageous, as already mentioned in the introduction, to supply the medicament virtually continuously in periodic bursts, the medicament, for example, in one-minute intervals during Pumps or intervals lasting 10 to 30 seconds can be pumped into the body. If the pump is intended for intermittent operation, the electronic device can therefore be designed, for example, in such a way that it maintains the excitation voltages that are currently present at the excitation electrodes at the end of a surge, so that the piezoelectric element maintains its shape during the pump interruption. Instead, however, it can also be provided that the electronic device deenergizes all four excitation electrodes in the pump interruptions between successive pump pulses. In the latter case, the electronic device may also be designed to excite the four transducer sections in such a way that all four pumping spaces 5051, 5053, 5055 and 5057 are emptied immediately before the end of each pump surge or pump interval.

The electronic device 5081 can of course also be provided with at least one manually operable switching and / or actuating element in order to switch the pump on and off switch off and / or to set the frequency and / or magnitude of the excitation voltages and thereby the delivery rate and / or to set the time intervals and durations of the pump pulses during intermittent operation.

The pump thus enables a fluid to be conveyed continuously or intermittently, peristaltically and practically uniformly, through a cell progressively progressing along the conveying passage in the intended conveying direction, without the pump needing any non-return or other valves for this purpose. The pump produces a relatively high degree of efficiency when converting electrical energy into mechanical energy that can be used for pumping. Since the piezoelectric transducer 5005 is firmly and tightly connected to the contact element 5003 along its edge which remains undeformed during operation and completely surrounds all deformable transducer sections, no parts which are movable with respect to one another need to be sealed from the surrounding space, which is also very advantageous.

The simple construction of the pump means that it can be manufactured very cost-effectively - at least in series production. Since when pumping a fluid only the two mutually facing surfaces 5035, 5037 of the contact element 5003 or delivery element 5005 as well as the two fluid connections 5071, 5073 come into contact with the fluid, the pump can also be made effortlessly sterile if necessary and during operation keep sterile. Furthermore, the configuration of the contact element 5003 and the piezoelectric transducer 5005, which is symmetrical with respect to the conveying direction, makes it possible to reverse the conveying direction only by changing the temporal course of the transducer deformations. If necessary, the electronic device can therefore be designed to be an optional one To enable changing the conveying direction by manually actuating a switching element.

The electronic device could be modified such that the four transducer sections 5041, 5043, 5045, 5047 are deformed over time according to the highly schematic, diagrammatic illustration in FIG. 60. In this, the contact element and the curved transducer sections are only represented by dashes, the partial figures or partial diagrams arranged from top to bottom illustrating successive states in time and subsequently being counted continuously from top to bottom. The first, ie uppermost, and the second partial figure of FIG. 60 show states or deformations of the transducer 5005 which are identical to the states or deformations shown in FIGS. 54 and 55, respectively. In the third partial figure of FIG. 60, only the third transducer section 5043 is then bulged. In the fourth part of FIG. 60, the piezoelectric transducer has the same shape as in FIG. 56. In the fifth part of FIG. 60, only the third transducer section 5045 is bulged. The deformations of the piezoelectric transducer shown in the sixth and seventh partial figures of FIG. 60 are again identical to those in FIGS. 57 and 58. In addition, arrows in the top and bottom partial figures show the inflow and outflow of Fluid indicated by the two fluid connections. In the fluid delivery illustrated by Figure 60, the transducer sections are deformed in repetitive cycles, each of which has six cycles. Otherwise, the pumping is carried out in a peristaltic manner similar to the operation of the pump illustrated by FIGS. 54 to 58. When the pumped fluid is at least essentially liquid and therefore practically incompressible , the fluid in the states shown in the fourth and sixth part-figure, in which two adjacent transducer sections are bulged, does not completely fill the two contiguous pumping spaces delimited by these and the carrier.

FIG. 61 shows, in a diagrammatic representation analogous to FIG. 60, yet another possibility of conveying fluid from the fluid connection 5071 to the fluid connection 5073 by deforming the four converter sections 5041, 5043, 5045, 5047. The uppermost, first part of FIG. 61 shows a state in which the piezoelectric has the same shape as in FIG. 54. In the second and third part of FIG. 61, counting from top to bottom, only the second is shown Transducer section 5043 or only the third transducer section 5045 bulges. In the bottom part of FIG. 61, the piezoelectric transducer then has the same shape as in the top part of the figure, so that the state shown in the bottom part of the figure also corresponds to the state in FIG. 58. If the piezoelectric transducer is deformed in the course of time according to FIG. 61, each of the repeating cycles has three cycles.

The elongated pump shown schematically in FIG. 62 has a pump body 5101, which is formed from two at least substantially symmetrical delivery members 5103, each with a piezoelectric transducer 5105. Each of these has two, layer-shaped, one-piece elements 5107 and 5109 made of piezoelectric material. A first, second, third and fourth excitation electrode 5111 or 5113 or 5115 or 5117 are arranged between these two elements 5107 and 5109. Like the excitation electrode 5011, 5013, 5015 and 5017, these are distributed over the length of the piezoelectric transducer and can have the same outline shapes like this as well as incisions in which detector electrodes are arranged. The two piezoelectric elements are each provided with a counter electrode 5131 on their mutually facing sides. A counter electrode 5133 is provided on the sides of the two elements 5109 facing away from each other. The counter electrodes 5131, 5133 each extend contiguously at least over the area occupied by the excitation electrodes in a projection from above. The two conveying bodies 5103 are along their in said

Projection of the edge zone surrounding the excitation electrodes analogously to the contact element 5003 and the conveying element 5004, firmly and tightly connected to one another, for example welded and / or glued. The surfaces of the conveying members 5103 located within the welded and / or glued edge zone, facing each other, each of which is formed by one of the counter-electrodes 5131, which is flat in the idle state shown in FIG. 62 and is adjacent but deformable, are referred to as conveying surfaces 5137 . The four excitation electrodes 5111, 5113, 5115, 5117 define four transducer sections 5141, 5143, 5145, 5147 in each of the two piezoelectric transducers 5105.

The piezoelectric elements 5105, 5107 are, like the elements 5005, 5007, stretchable by applying electrical voltages to the excitation electrodes, so that each transducer section 5141, 5143, 5145 and 5147, based on its rest shape shown in FIG piezoelectric transducers 5105 is archable away through the plane. FIG. 63, in which the two conveying members and their piezoelectric transducers are shown in a highly simplified manner, shows a state in which the two first transducer sections 5141 and the two fourth transducer sections 5147 are curved away from one another. Those with the same reference Symbol-designated transducer sections together thus delimit in pairs a first, second, third, fourth pump chamber 5151 or 5153 or 5155 or 5157, the volume of which can be changed between a maximum value which arises when the transducer section pair is curved and zero. The four pumping spaces 5151, 5153, 5155, 5157 together form the delivery passage 5149 of the pump. The pump has a fluid connection 5171 opening into the first pump chamber 5151 and a fluid connection 5173 opening into the fourth pump chamber 5157. For example, the two fluid connections can be inclined at one end of one of the two delivery elements 5103 through its edge zones be introduced into the pumping rooms mentioned. The pump shown in FIGS. 62 and 63 also has an electronic device, not shown, which is designed similarly to the electronic device 5081 and can likewise be connected to a supply voltage source equipped with at least one battery. The excitation electrodes 5111, 5113, 5115 and 5117, which have the same reference numerals, and counterelectrodes 5131, 5133 are connected in pairs in an electrically conductive manner to one another and to the electronic device. In contrast, the eight detector electrodes (not shown) are expediently each separately connected to the electronic device so that it can monitor the function of each individual converter section.

The pump shown in FIGS. 62 and 63 thus differs from the pump described with reference to FIGS. 50 to 59 primarily in that it has a second deformable delivery element 5103 instead of the contact element 5003 which remains undeformed during pumping. The pump shown in FIGS. 62 and 63 can similarly peristaltically pump a fluid through its delivery passage 5159, as is the case for those according to FIGS FIGS. 50 and 51 designed pump has been described with reference to FIGS. 54 to 58, but in the case of the pump according to FIGS. 62 and 63 both converter sections designated by the same reference numerals are simultaneously deformed mirror-symmetrically to one another. Apart from the differences resulting from the symmetrical arrangement of two piezoelectric transducers, the pump shown in FIGS. 62 and 63 therefore has essentially the same properties as those discussed for the pump described with reference to FIGS. 50 to 59. Furthermore, it is of course also possible for the pump shown in FIGS. 62, 63 to operate it analogously to the operating sequences illustrated in FIGS. 60 and 61.

As previously discussed, the piezoelectric transducer 5005 is designed in such a way that its two elements 5007 and 5009 are extended in all directions measured parallel to the conveying surfaces 5037 when the transducer sections bulge. The piezoelectric transducers 5105 can also be designed in this way. However, the two piezoelectric layers of the elements of transducers 5005 and 5105 could also be formed, in particular pre-polarized, and the directions of the electrical fields acting on the piezoelectric elements for deforming the transducers determined in such a way that the two elements measured their parallel to the conveying surfaces Change dimensions in the opposite direction in the event of deformation. Instead, one could design the or each piezoelectric transducer as a monomorph transducer and accordingly provide it with only one layer-like element which can be lengthened or shortened by electric fields in the directions running along the conveying surface, which element then does not change its dimensions in cooperation with one the layered bending body could produce bulges. As will be described in more detail with reference to FIGS. 64 to 66, the dome-shaped curvatures of the transducer sections can also be generated by shearing when using a piezoelectric transducer with only a single, piezoelectric, layer-shaped element. In the case of these variants, in which the or each piezoelectric transducer has two piezoelectric elements which are connected in the region of the entire conveying passage and whose dimensions, measured along the conveying surface, change in the opposite direction during deformation, or only a single piezoelectric element, the diameter of the transducer sections or in more general terms, the distance from transducer section edge points located on opposite sides of the transducer section axis is not kept constant when the transducer sections are deformed. So that the changes in the distance between the edge of the transducer section nevertheless do not generate excessive mechanical stresses, the or each piezoelectric element in these variants can be formed, for example, from the "composite" material already described, which is softer than a material consisting exclusively of ceramic.

The piezoelectric transducer 5205 shown in FIGS. 64, 65 and 66 has only a single piezoelectric, layer-shaped element 5207. The drawn section of the element 5207 is on its upper side in FIG. 64 with a first, second and third excitation electrode 5211 or 5213, wherein the entire transducer 5205 can, for example, also have a fourth exciter electrode which is no longer visible. On the side of the piezoelectric element 5207 which is at the bottom in FIG. 64, there is a coherent area of all excitation electrodes extending counter electrode 5231 present. The excitation electrodes define a first, second and third transducer section 5241 and 5243 and 5245, respectively. In FIGS. 64 and 66, the axes of the transducer sections running through the centers of the enveloping circles of the exciter electrodes are also drawn, of which that of the first transducer section with 5261 is designated. The piezoelectric element 5207 is pre-polarized in its manufacture in such a way that in the region of each transducer section 5241, 5243, 5245 it has a pre-polarization or, in short, polarization P which is at least generally radially directed to its axis. The statement "in general" takes into account the fact that the piezoelectric domains that can be aligned during polarization have finite dimensions, ie are not infinitely small, and therefore are not exactly radially directed in every point, and that, moreover, at the joints of adjacent transducer sections imperfectly polarized areas may be present. For example, the polarization vectors can be directed outward from the transducer section axes. The z axis or third axis of the domains of the piezoelectric lead zirconate titanate belonging to the hexagonal crystal system is then parallel to the polarization vectors.

If, for example, an electrical voltage which is positive with respect to the counter electrode 5231 is applied to the excitation electrode 5211 of the first converter section 5241, the section of the element 5207 belonging to this converter section, which is shown in FIG. 66, acts from the excitation electrode to the counter -Electrode and thus generally downward electric field E. This causes in the sector-shaped converter section parts that are opposite each other with respect to the axis 5261 of the first converter section 5241 sensible shears. These bulge the first transducer section 5241 away from the plane spanned by the counter-electrode 5231 in the idle state against the restoring forces generated by the elasticity of the piezoelectric element. The magnitude of the shear is proportional to the two for the lead zirconate titanate belonging to the hexagonal crystal system equally large piezoelectric coefficients d _{1 5} and d _{2 4} .

You can connect the piezoelectric transducer 5205 either analogously to the piezoelectric transducer 5005 to a dimensionally stable contact element or analogously to the piezoelectric transducer 5105 to another piezoelectric transducer, which can then also be deformed by shear. With a pump body formed in one of these ways, a fluid can be pumped peristaltically in the same way as with the pump bodies 5001, 5101.

FIG. 67 shows a one-piece, strip-shaped, piezoelectric element 5307 with four excitation electrodes 5311, 5313, 5315, 5317. The latter, like the excitation electrodes 5011, 5013, 5015, 5017, generally have a circular outline and at least one circular arc-shaped edge section. However, the electrodes 5311, 5313, 5315, 5317 have, at their circumferential locations where they are adjacent to one another along the conveying passage to be formed, concavely curved edge sections instead of edge sections consisting of circular eyes. Each of the four excitation electrodes is connected to a connecting conductor track section that runs to one longitudinal edge of element 5307. The first and fourth excitation electrodes also have a circular opening or recess in which detector electrodes 5321 and 5327 are arranged. The piezoelectric element 5307 can, for example, be analog with the electrodes arranged thereon such as element 5007, elements 5107 or element 5207 polarized and assembled with other components to form a pump body.

In the case of transducers whose exciter electrodes are the same as those of the transducers 5005, 5205 according to FIGS. 51 and 65, in the case of their circumferential parts which are adjacent to one another in pairs by edge sections formed by straight lines which are parallel to one another and parallel to the longitudinal direction of the conveying passage, it may depend on The other design of the transducers means that when a transducer section bulges, the adjacent transducer section is also partially lifted off the opposing contact or conveying surface without supplying excitation voltage. The concavely curved edge sections of the excitation electrodes 5311, 5313, 5315, 5317 can, on the one hand, reduce undesirable co-deformations of a converter section immediately adjacent to an arched converter section and, on the other hand, achieve a good connection of the assigned pumping spaces while simultaneously intentionally bulging two adjacent converter sections.

The pump shown in FIG. 68 has a pump body 5401 with a dimensionally stable, one-piece, plate-shaped contact element 5403 forming a flat contact surface 5435a and a delivery element 5404 which is at least essentially formed by a converter 5405. This has four individually dome-shaped curvature transducer sections 5441, 5443, 5445, 5447 and a flexible, piezoelectric film 5406 which extends cohesively over the entire conveyor passage to be formed. The transducer 5405 is further provided with a separate bimorph transducer device for each of the four transducer sections, two of which are each one Disc-shaped, piezoelectric elements 5407 and 5409 has. An excitation electrode 5411 is arranged between each of the two piezoelectric elements belonging to the same bimorph transducer device. On the side of the piezoelectric film 5406 facing the contact element, there is a counter-electrode 5431 which extends cohesively over the entire conveying passage to be formed, the side of which facing the contact element forms the conveying surface 5437. On the side of the piezoelectric film 5406 facing away from the contact element 5403, there are particularly clearly visible electrodes in FIG. 69, for which a counter-electrode 5451 for the first and fourth transducer sections 5441 and 5447 and one for the second and third transducer sections 5443, 5445 Include counter electrode 5453. The counter electrodes 5451 have similar shapes to the excitation electrodes 5311, 5317 and the counter electrodes 5453 have similar shapes to the excitation electrodes 5313, 5315. The first and fourth transducer sections 5441 and 5447 each have an arcuate auxiliary electrode 5455 is present, which runs along the convex, circular-arc-shaped edge section of the counter-electrode 5451 present in the relevant converter section. The second and third transducer sections 5443 and 5445 each have two arc-shaped auxiliary electrodes 5457 which run along the two convex, circular-arc-shaped edge sections of the counter-electrodes 5453. Auxiliary electrodes 5459 are arranged in the recesses formed by the concave, arcuate edge sections of the counter electrodes 5451, 5453. A counter electrode 5433 is arranged on the side of each piezoelectric element 5409 facing away from the contact element 5403.

The surfaces of the various components of the converter 5405 which are in contact with one another are firmly and electrically connected to one another. The between the piezoelek tric film 5406 and the piezoelectric elements 5407 and the electrodes present between a pair of piezoelectric elements 5407 and 5409 can each consist of a single metal foil or two metal layers each, which face the mutually facing surfaces of the piezoelectric film 5406 and elements 5407 and the mutually facing surfaces of the piezoelectric elements 5407 and 5409 are applied, for example vapor-deposited and connected to one another. Furthermore, the transducer is firmly connected to the contact element 5403 along its edges surrounding the conveying passage during operation. The contact element 5403 is provided with two fluid connections 5471, 5473, which open into the contact surface 5435 at the ends of the conveying passage formed during operation that face away from one another. Furthermore, there is a rubber-elastic pressing body 5475, which is firmly connected to the contact element 5403, does not enclose the boundaries of the transducer 5405 and resiliently presses the transducer against the contact surface 5435. It should also be pointed out that, like many of the previous figures, FIG. 68 is not to scale and that in particular the electrodes are drawn with greatly exaggerated thicknesses.

The flexible piezoelectric film 5406 consists of polyvinylidene difluoride (PVDF) and was made piezoelectric and polarized during production by stretching under the simultaneous action of an electric field. The film 5406 can then be stretched at least in a direction parallel to the contact surface, for example transversely to the longitudinal and conveying direction of the conveying member, by an electric field acting on it during operation of the pump. However, the film can also be stretched and polarized during its manufacture in such a way that it operates both transversely and parallel to the conveying direction when the pump is operated under the action of an electric field and is therefore stretchable radially to the center of the respective transducer section. The piezoelectric elements 5407, 5409 formed from disks, like the piezoelectric elements 5007 and 5009 described above, consist of a piezoelectric ceramic material.

The counter electrodes 5431, 5433, 5451, 5453 are connected to the ground connection of an electronic device, not shown, which is designed, for example, to supply excitation voltages positive to ground against the excitation electrodes. The polarizations of the piezoelectric elements 5407 and 5409 and the polarity of the excitation voltages are matched to one another in such a way that the excitation voltage supplied to an excitation electrode causes a contraction of the element 5407 and an expansion of the element 5409 and thus a dome-shaped bulge of the relevant transducer section. When a transducer section is arched, the auxiliary electrodes 5455 and 5459 or 5457 and 5459 belonging to it are simultaneously supplied with an auxiliary voltage, which has the effect that the more or less annular region of the piezoelectric foil 5406 covered by the auxiliary electrodes is covered in at least one extends in the direction parallel to the conveying surface 5437 and, for example, radially to the center of the converter section in question. Through this

Elongation can be at least partially compensated for when the transducer section bulges in a projection onto the flat contact surface 5435, the reduction in the envelope diameter of the transducer section in question. The sections of the flexible film 5406 that are located at the boundaries between adjacent transducer sections also form, to a certain extent, joints. These joints, together with the pressing body 5475 which resiliently presses the transducer against the contact element, ensure that when at least one transducer section bulges, the or each of the adjacent, non-bulging transducer sections at least largely maintains its resting shape and is actually not bulging, but lies as completely as possible against the contact surface.

The pump shown in simplified form in FIG. 70 has a pump body 5501 with a contact element 5503 consisting of a dimensionally stable, elongated plate and a conveying element 5504. This has a transducer 5505 with a flexible and elastically stretchable film 5506, which is made of polypropylene, and four on this attached, each defining a transducer section, piezoelectric bimorph transducer device 5511, each of which has two piezoelectric elements and electrodes. The mutually facing surfaces of the contact element 5503 and the film 5506 form the flat contact surface 5535 and the conveying surface 5537, which can be domed out in the form of a dome in each transducer section. Two fluid connections 5571 and 5573 open into the contact surface at the ends of the conveying passage which arise during operation. The film 5506 is tightly and firmly connected to the contact element 5503 along its edges surrounding the conveying passage. Pressure means have a hood 5575 fastened to the contact element 5503 and a bellows 5579. The cavity present between the converter 5505 and the inner surface of the hood 5577 contains a hydraulic fluid which is made of silicone oil and which is pressurized by the bellows 5579 and resiliently presses the converter against the contact element.

In operation, the 5511 bimorph transducer devices can be individually domed. The stretchable and flexible film 5506 can reduce the enveloping diameter of the bulging Compensate converter sections by stretching them in certain areas. The sections of the flexible, elastically stretchable film 5506 which are located in the boundary regions at and between the mutually adjacent bimorph transducer devices form, to a certain extent, elastic joints in a manner analogous to the corresponding sections of the piezoelectric film 5406. The pressing means formed by the hood 5577, the bellows 5579 and the hydraulic fluid ensure that the conveying surface sections belonging to non-bulging transducer sections rest on the contact surface.

The pump shown in part in FIGS. 71 and 72 has a pump body 5601 with a dimensionally stable contact element 5603 and a delivery element 5604. This in turn consists at least essentially of a transducer 5605 with two layer-shaped, piezoelectric elements 5607 and 5-609. Between these two elements there is a central excitation electrode 5611 for each transducer section and an external excitation electrode 5613 surrounding it in a ring. On the sides of the two elements 5607 and 5609 facing away from each other there are contiguous counter-electrodes 5631, 5633. An electronic device, not shown, has excitation connections connected to the excitation electrodes and a ground connection connected to the counter electrodes. For domed arching of a transducer section, the electronic device feeds excitation voltage signals to the relevant excitation electrodes. These are matched to the polarizations of the piezoelectric elements 5607, 5609 in such a way that the element 5607 contracts in its central area covered by the excitation electrode 5611 and in its peripheral area covered by the outer excitation electrode 5613 and that it expands the element 5609 in the central The area stretches and contracts in the peripheral area. By appropriately determining the polarizations of the piezoelectric elements and the maximum values of the excitation voltages, it can be achieved that the enveloping circle diameter of a transducer section when bulging in a

Projection onto the flat contact surface remains at least reasonably constant.

FIG. 73 shows a highly schematic representation of a reusable pump which has a pump body 6801 with an invisible, plate-shaped, one-piece contact element and a delivery element arranged thereon. This consists at least essentially of a likewise plate-shaped transducer 6805 with a number of transducer sections 6841 that can be arched up in the manner of a dome

Contact member and the conveying member form a contact surface or conveying surface on their mutually facing sides. The converter 6805 can, for example, have a similar layer structure to the converter 5005 and is firmly and tightly connected to the contact element along its edges surrounding all bulging converter sections, for example welded and / or glued. Each transducer section, together with the section of the contact element which it covers, delimits a pump chamber. The transducer sections located in the drawn projection onto the plane spanned by the pump body in the idle state in the inner region of the pump body are each surrounded by three other transducer sections adjoining them, evenly distributed around their center. The pumping spaces adjacent to one another together form a reusable conveying passage or conveying passages. Each section of a conveying passage extending over three or more adjacent pump spaces forms at least one angle. At least part of the pumping spaces located at the edge of the pump body is connected to fluid connections, one example being a fluid connection 6871 for the edge section located on the left and right in FIG. 73 and four fluid connections 6873 each for the upper and lower edge section.

In the idle state, the conveying surface is the same as the contact surface and lies against it. During the operation of the pump according to FIG. 73, fluid can be pumped by arching and flattening the transducer sections along different conveying passage sections or conveying passages. The pumping spaces, each surrounded by three other pumping spaces, serve as branching points and thus, together with the pumping spaces and pump sections adjacent to them, form, as it were, reusable valves or flow switches. The desired delivery paths and directions can be determined during operation of the pump by selecting the converter section deformed over time for a pumping process. The two fluid connections 6871 can serve, for example, as inlets and the fluid connections 6873 as outlets. The pump can be used, for example, for a blood test in which blood is drawn from a patient at certain time intervals in order to examine the change over time of a substance present in the blood, such as a previously supplied medication. For this purpose, the fluid connection 6871 located on the left side of FIG. 73 is connected to a hollow needle that is inserted into a vein of the patient and is used for taking blood. The other fluid port 6871, which serves as an inlet, is connected to a reservoir which contains a blood-preventing or at least inhibiting liquid, such as heparin. Sample containers serving to receive blood samples are connected to the fluid connections 6873 when performing a Before each blood sample is taken, a certain amount of heparin is pumped into the cavity of the needle. When a blood sample is taken, the blood drawn together with the heparin contained in the needle is pumped into one of the sample containers, and each time a blood sample is taken into a different sample container. If necessary, a certain amount of heparin can be pumped into the sample container at the end of a blood sample. The course of the various pumping processes can be controlled, for example, by process computers. Otherwise, the

The number of the fluid connections 6873 serving as outlets can be set larger or smaller than the number shown in FIG. 73 in accordance with the number of samples provided for an analysis.

The reusable pump can also be modified in such a way that the centers of the converter sections and the associated pumping spaces lie in a projection onto the flat contact surface on the intersection points of two groups of straight lines crossing at right angles and thus together form a rectangular or square matrix. The transducer sections and pump spaces located in the above-mentioned projection in the inner region of the pump body are then each surrounded by four transducer sections and pump spaces directly adjacent to them and distributed around them.

Instead of the blood test described, a reusable pump can also be used for a large number of other purposes, in which liquids supplied through different inlets are to be pumped to the same outlet, or a liquid coming from an inlet is to be pumped to different outlets. Furthermore, such a reusable pump enables several liquids to be separated from each other pump or mix, possibly react chemically with each other when mixing and break it down again into partial flows. In addition, the pumping rooms could be equipped with sensors of any kind.

The pumps can be modified in other ways. In particular, many features of the various exemplary embodiments described can be combined with one another in manifold ways. For example, all pumps having individually bendable converter sections described with reference to FIGS. 24 to 73 can operate with excitation voltages, which form sequences of excitation signals, which either consist of angular pulses or have a continuously changing course everywhere. The excitation voltages can, for example, also form triangular or trapezoidal pulses or signals which are generally triangular or trapezoidal, but which instead of corners have continuous, rounded transitions. Furthermore, all of the pumps described with reference to FIGS. 24 to 73 can be operated with excitation voltages that have a sinusoidal course over time. The excitation voltages are - depending on the type of pump and its converter means - to be formed by AC voltages or by DC voltages that change over time. In the exemplary embodiments in which the polarization directions of the sections of the piezoelectric elements and / or the polarities of the excitation voltages are specified, the polarization directions of the piezoelectric elements or the polarities of the voltages can of course be reversed.

Claims

1.Pump with two connections (17, 19, 2017, 2019, 5071, 5073), a passage (77, 2077, 5049) connecting them during operation and converter means (43, 2043, 5005), the passage (77 , 2077, 5049) in cross section on one side by a conveyor surface (45a, 2045a, 5037) which is bendable at least in places by the transducer means (43, 2043, 5005) such that a fluid is bent by bending the conveyor surface (45a, 2045a , 5037) can be conveyed through the passage (77, 2077, 5049), characterized in that the passage (77, 2077, 5049) on its side opposite the conveying surface (45a, 2045a, 5037) in cross section through an at least between the mouths of the two connections (17, 19, 2017, 2019, 5071, 5073) in the passage (77, 2077, 5049) in the idle state everywhere the area parallel to the conveying surface (45a, 2045a, 5037) (15a, 2015a, 5035) is limited.

2. Pump according to claim 1, characterized in that the two mentioned surfaces (15a, 45a, 2015a, 2045a, 5035, 5037) serving to limit the passage (77, 2077, 5049) each form a continuous control surface in the idle state.

3. Pump according to claim 1 or 2, characterized in that the two named surfaces (15a, 45a, 2015a, 2045a, 5035, 5037) serving to limit the passage (77, 2077, 5049) are flat in the idle state.

4. Pump according to one of claims 1 to 3, wherein the transducer means (43, 2043, 2143, 5005) at least one transducer (43, 2043, 2143, 5005) with two to the delivery surface (45a, 2045a, 2145, 5037) has parallel surfaces and are designed to bend the conveying surface (45a, 2045a, 2145a, 5037) against each other, characterized in that the transducer means (43, 2043, 2143, 5005) are designed to cover the conveying surface (45a, 2045a, 2145a, 5037) when pumping all between the mouths of the fluid connections (17, 19, 2017, 2019, 5071, 5073) in the passage (77, 2077, 5049), sections of the passage (77a, 2077, 5049) at least at times from those opposite the conveying surface (45a, 2045a, 2145a, 5037) Separate surface (15a, 2015a, 5035) by a free space and promote the fluid peristaltically through the passage (77, 2077, 5049).

5. Pump according to one of claims 1 to 4, characterized in that the two surfaces (15a, 45a, 2015a, 2045a, 5035, 5037) serving to limit the passage (77, 2077, 5049) serve to rest against one another in the idle state .

6. Pump according to one of claims 1 to 5, characterized by means (13, 55, 2013, 5007, 5009, 5475,

5575, 5579) around the conveying surface (45a, 2045a, 5037, 5437, 5537) and the surface (15a, 2015a, 5035, 5435, 5535) delimiting the passage (77, 2077, 5049) on the opposite side to push each other.

7. Pump according to one of claims 1 to 6, characterized in that the transducer means (43, 2043) are designed to pump the conveying surface (45a, 2045a) starting from a flat or cylindrical or conical resting shape taken in the idle state to be deformed in a wave-like manner in a section running along the conveying direction in such a way that the resulting wave crests (75, 2075) extend transversely to the conveying direction over the entire extent of the passage (77, 2077, 3177) extend and move in the conveying direction, and that the passage (77, 2077) is closed at both ends by means of deformation movements of the conveyor surface sections provided there, closing means (13d, 13e, 2013d, 2013e, 3135) against the environment.

8. Pump according to claim 7, characterized in that the passage (77, 2077, 3177) along the conveying direction at two edges facing away from one another by means of deformation movements of the conveying surface sections present there enables closing means (13b, 13c, 2013b, 2013c, 3135) against the environment is completed.

9. Pump according to claim 7 or 8, characterized in that the closing means (13b, 13c, 13d, 13e, 2013b, 2013c, 2013d, 2013e, 3135) are at least partially elastically deformable.

10. Pump according to one of claims 7 to 9, characterized in that all said closing means (13b,

13c, 13d, 13e, 2013b, 2013c, 2013d, 3135) are formed by sections of a one-piece body (13, 2013, 3135).

11. Pump according to one of claims 7 to 10, characterized in that the transducer means (43, 2043) are designed to deform the conveying surface (45a, 2045a) in such a way that in each possible state during pumping at least one the wave crest (75, 2075) protruding towards the passage (77, 2077) on the surface (15a, 2015a) delimiting it, which forms between the junctions of the connections (17, 19, 2017, 2019) in the passage ( 77, 2077).

12. Pump according to one of claims 7 to 11, characterized in that the passage (77) runs along an arc and that the transducer means (43) are designed to move the wave crests formed by the conveying surface (45a) along an arc .

13. Pump according to claim 12, characterized in that a body (45) forming the delivery surface (45a) is at least substantially rotationally symmetrical to an axis (5) extending through the center of the circular arc and that the converter means (43) is at least one Comprising a piezoelectric element and being designed to generate at least one elastic wave which extends in the interior of the body (45) forming the conveying surface (45a) around the axis (5).

14. The pump as claimed in claim 13, characterized in that the transducer means (43) and an electronic device (61), which is electrically connected to the latter and is used to supply electrical voltages to them, are formed around the body (45a) forming the conveying surface (45a). 45) to vibrate with a resonance frequency in the ultrasonic range.

15. Pump according to one of claims 12 to 14, characterized in that the surface (15a) opposite the delivery surface (15a) by a stator (2) and the delivery surface (45a) by an axis with respect to the stator (2) ( 5) rotatable rotor (3) is formed and that the transducer means (43) are designed to deform the conveying surface (45a) in such a way that the or each wave crest (75) arising on the conveying surface (45a) is attacked on the Stator (2) generates a force for rotating the rotor (3), the converter means (43) are rotatably connected to the rotor (2) so that they rotate together with the rotor (2) during operation.

16. Pump according to one of claims 7 to 12, characterized in that the transducer means (2043, 2143, 2243, 3143) are designed to individually bend conveying surface sections distributed along the passage (2077, 3177) and thereby generate wave crests ( 2075) step by step along the passage (2077, 3177) and that a conveying element (2041, 2141,) forming the conveying surface (2045a, 2145a, 2245a, 3145a) and having at least one transducer (2043, 2143, 3143) 3141) is connected to the closing means (2013b, 2013c, 2013d, 2013e, 3153) in such a way that it can change its extent measured along the passage (2077, 3177) when the conveying surface (2045a, 2145a, 2245a, 3145a) is deformed in a wave shape.

17. Pump according to claim 16, that the conveying member (2041, 2141, 2241, 3141) bears on its side facing away from the conveying surface (45a, 2045a, 2145a, 3145a) against a body (35, 2035, 3135) which is expandable in the conveying direction.

18. Pump according to claim 17, characterized in that on the conveying member (3141) on the conveying surface

(3145a) on the side facing the body (3135) is rubber-elastic.

19. Pump according to claim 17 or 18, characterized in that the on the delivery member (3141) at the

Body (3135) lying on the opposite side of the conveying surface (3145a), the conveying element (3141) and the organ (3141) forming the surface (3145a) opposite the conveying surface (3145a) in at least one of the two organs (3141) completely and coherently enclosing the cutting plane.

20. Pump according to one of claims 1 to 19, wherein the transducer means (2043, 5205) have at least one piezoelectric element (2044, 5207), characterized in that the piezoelectric element (2044, 5207) is arranged, pre-polarized and is provided with electrodes (2045, 2047, 5211, 5213, 5215, 5231) that by applying an electrical voltage to the electrodes (2045, 2047, 5211, 5213, 5215, 5231) a shearing of the conveying surface (2045a) of sections (2043a) of the piezoelectric element (2044, 5207) can be effected.

21. Pump according to one of claims 1 to 19, wherein the transducer means (2243, 5005) have at least one piezoelectric element (2251, 5007), which is pre-polarized and with electrodes (2247, 2255, 5011, 5013, 5015, 5017 , 5031) is provided such that by applying an electrical voltage to the electrodes (2247, 2257, 5011, 5013, 5015, 5017, 5031) to the conveying surface (2245a, 5037), parallel deformations of the piezoelectric element (2251, 5007) can be generated, characterized in that the piezoelectric element (2251, 5007) is connected to another piezoelectric element (2253, 5009) at a surface parallel to the conveying surface (2245a, 5037), which is also connected to electrodes (2245, 2257, 5011, 5013, 5015 , 5017, 5033) and can be deformed by applying an electrical voltage to them parallel to the conveying surface (2245a, 5037), so that interconnected sections (2251a, 2253a) of the two piezoelectric elements (2251, 2253, 5007, 5009) G are easily deformable at different times.

22. Pump according to claim 21, characterized in that the transducer means (3143) are designed to individually bend conveying surface sections distributed along the passage (3177) and thereby move wave crests step by step along the passage (3177), that the closer to the conveying surface (3145a) and / or forming it, piezoelectric element (3151) on its side facing away from the conveying surface (3145a) with two narrower piezoelectric elements which run alongside the passage (3177) and are separated from one another by a space Elements (3153) and that between the interconnected piezoelectric elements (3151, 3153) along the passage (3177) distributed electrodes (3155, 3157) are present and are connected to electrical connecting lines which are connected by the narrower one between the two Piezoelectric elements (3153) existing space.

23. Pump according to one of claims 1 to 18, characterized in that the transducer means (2343, 2345, 2351) thermoelectric elements (2351) for converting electrical signals into temperature changes and a transducer with two interconnected, layer and / or have strip-shaped elements (2343, 2345) made of different materials having thermal expansion coefficients, for example both materials being metallic or for example at least one of these materials being metallic or ceramic or a glass.

24. Pump according to one of claims 1 to 12, 16 to 23, characterized in that the area delimiting the passage (3077, 3177, 5149) with respect to the delivery surface (3041a, 3145a, 5137) also by means of a transducer means assigned to it (3043, 3143, 5105) bendable conveying surface (3041a, 3145a, 5137) is formed.

25. Pump according to claim 24, characterized in that the transducer means (3043, 3143, 5105) are designed to bend the opposing delivery surfaces (3041a, 3145a, 5137) at least substantially mirror-symmetrically to one another.

26. Pump according to one of claims 1 to 6, 20, 21,

23, 24, 25, the transducer means having at least one transducer (5005) with transducer portions (5041, 5043, 5045, 5047) distributed along the passage (5049) and serving for the domed arching of conveying surface portions, characterized in that the transducer (5005) is formed to form a coherent cavity forming a section of the passage (5049) by means of simultaneous, dome-like transducer sections (5041, 5043, 5045, 5047) which are adjacent to one another in pairs along the passage (5049).

27. Pump according to claim 26, characterized in that a conveying member forming the conveying surface (5037)

(5004) and an organ (50049) delimiting the passage (5049) at least substantially along the entire edges of the conveying surface (5037) - for example apart from any openings which are present there and serve to form connections - tightly and tightly with one another are connected.

28. The pump of claim 26 or 27, wherein the transducer

(5005) has at least one piezoelectric element (5007, 5009, 5307), which extends coherently over the entire passage (5049) and has surfaces parallel to the conveying surface (5037) and at least on one of the two Surfaces of the or each piezoelectric element (5007, 5009, 5307) each have an associated one of the aforementioned transducer sections (5041, 5043, 5045, 5047), which serves to effect a bulge from this electrode (5011, 5013, 5015, 5017, 5311 , 5313, 5315, 5317), characterized in that the edges of the said electrodes (5011, 5013, 5015, 5017, 5311, 5313, 5315, 5317, each associated with an individual transducer section (5041, 5043, 5045, 5047) ) at least one circular arc-shaped edge section and at the peripheral points at which these electrodes (5011, 5013, 5015, 5017, 5311, 5313, 5315, 5317) are adjacent to one another in pairs along the passage (5049) have a straight or concave curved edge section .

29. Pump according to claim 21 and one of claims 26 to 28, characterized in that the two interconnected, layer-shaped, piezoelectric elements (5007, 5009) coherently over the entire passage (5049) that one electrically with the electrodes (5011, 5013, 5015, 5017, 5031, 5033) connected electronic device (5081) is present in order to supply them with an electrical voltage (U ₁ , U ₂ , U ₃ , U ₄ ) and thereby deform the transducer (5005) cause, and that the two piezoelectric elements (5007, 5009) and the electronic device (5081) are designed such that the dimensions of the two elements (5007, 5009) measured along the conveying surface (5037) when a transducer section (5041, 5043, 5045, 5047) are enlarged to different extents so that the distances (d, d ') with respect to the axis (5061) of the relevant transducer section (5041) opposing edge points thereof change less when bulging than if only the said dimensions of a piezoelectric element (5007, 5009) were changed during bulging and / or if the said dimensions of the two piezoelectric elements (7, 9) were changed in opposite directions and remain at least approximately constant during the arching.

30. Pump according to one of claims 26 to 28, characterized in that the transducer (5405) has a flexible, piezoelectric film (5406) which extends coherently over the entire passage, at least on the side facing away from the passage for each individual archable transducer section a separate piezoelectric element (5407, 5409) is fastened, that the piezoelectric elements on the film (5406) in a projection onto the plane spanned by the conveying surface (5437) in the idle state at least partially enclosing auxiliary electrodes (5455, 5457, 5459) are attached so that the film (5406) can be stretched in the region of this when a transducer section bulges by applying an electrical voltage to the or each auxiliary electrode (5455, 5457, 5459) assigned to the transducer section in question.

31. Pump according to one of claims 26 to 28, characterized in that the transducer (5505) has a flexible, elastically stretchable film (5506) which extends coherently over the entire passage, on the side facing away from the passage for each individual archable transducer section at least one separate piezoelectric element is attached.

32. Pump according to one of claims 26 to 31, characterized in that there are at least four transducer sections (5041, 5043, 5045, 5047) distributed along the passage (5049) for doming an associated conveying surface section.

33. Pump according to one of claims 26 to 32, characterized in that at least a third connection (6871, 6873) is present in order to guide a fluid into and / or out of the passage and that the passage has at least one of a converter section (6841) has assigned pump space in order to form a branching of the passage in cooperation with at least three other pumping spaces each assigned to a different converter section (6841) and to enable the diversion and / or branching of a fluid stream and / or the combination of fluid streams.