WO1997046807A1

WO1997046807A1 - Force machine

Info

Publication number: WO1997046807A1
Application number: PCT/SE1997/000955
Authority: WO
Inventors: Tore Fors
Original assignee: Tore Fors
Priority date: 1996-06-05
Filing date: 1997-06-02
Publication date: 1997-12-11
Also published as: SE9602232L; AU3113197A; SE9602232D0

Abstract

The present invention is for a force machine intended to obtain a to and fro motion, the machine being especially useful for pumping of gases and liquids in various applications. The object of the invention is to obtain a device of the above-mentioned kind which with high efficiency converts the supplied energy into the decided movements. The force machine shown in the figure has two membranes (19, 20) to each of which there is a corresponding stator (2, 9) shaped as a grid, a thin plate or the like made from electrically conductive material. The two membranes (19, 20) are parallel to each other and connected by a firm, hard or stiff mounting material (6) which has a very low weight per volume.

Description

Force machine

The present invention is for a force machine or electric motor of the kind described below The force machine is primarily intended to generate a to and fro movement and it is especially useful for the pumping of gases and liquids in various applications

It is known in the art to obtain a to and fro motion by conversion of a rotating movement or by direct use of electromagnetic changes in designs using core and coil By these methods the efficiency is often low and the heat developed in electrical coils is often considerable Moreover the mechanical designs for conversion of rotating movement can be relatively complicated and require various support¬ ing systems for lubrication and other purposes

The object of the invention is a device of the above mentioned kind which at a high efficiency converts supplied energy into desired movement

The invention will below be described more in detail with re-ference to the examples of embodiments which are shown in the enclosed figures

Figure 1 is a cross-section of a preferred embodiment or force machine according to the invention and some basic elements of the electrical equipment which belongs thereto

Figure 2 shows a force machine according to the invention used as a membrane pump

The force machine shown in cross-section in figure 1 has two membranes 19, 20, and to each of them a corresponding stator 2, 9 shaped as a grid, a thin plate or the like, made from electrically conductive material The two membranes are parallel to each other and joined by an electrically insulating hard or stiff supporting material 6 In order to obtain low energy losses and thus a high efficiency the mateπai ought to have a low weight per volume This mateπai has essentially the same cross-section as the membranes, and these are mounted to other side of the material Preferably the membranes are joined to the material all over the surface thereof which is turned towards the membrane, or at points which are evenly distributed over the surface Suitable carrying material can be polyurethane foam or other polymer material, having 80-99% air content, and a weight per volume of about 20-200 kg/m³ The membranes and stators are mounted in a frame 3 by fastening screws 4, 5, so that stator and mem¬ brane in a pair are in electrically conductive contact with each other, while the pairs of membranes and stators are electrically insulated from each other in the carrying and mounting construction The volume between a membrane and a stator can be closed and for example used as a pumping chamber in the embodiment of the invention which is described below In this case there is a distance 25 between the material 6 which unites the membrane and the stator

Pairs of membranes 19, 20 and stators 2, 9 always have the same electrical potential and repel each other with a variable force when the potential varies Preferably all changes of voltages to the right and the left side are equal but have opposite directions, i e when the voltage increases on the left side, it decreases on the right side and the membranes are displaced to the right

As adjacent membrane and stator have the same potential and the membranes with different potentials are at a constant relatively large distance from each other, high potentials up to more than 100 kV may be used in a pair of membrane and stator The incoming voltage is supplied by a conductor 16 and ground 10 to a transformer, on the secondary side of which there is a middle connection for a prevolt- age of constant potential, a so called bias, 17 The voltage of the outlets of the transformer is con¬ nected to the pairs of stators and membranes by connections 11, 12

In a preferred embodiment of the invention there is a secondary membrane between a membrane and its stator The secondary membrane being an intermediate layer formed by thin lightweight nets or the like 7, 8 Which preferably are made from textile material which is electrically conductive or has been treated to be conductive In the figure there is only shown two such nets on the left side of the device These are in electrically conductive contact with one another and with the stator 2, and also through the conductor 1 , with the membrane 20 However the two sides ought to be of the same design, and the number of nets can be varied due to the actual application If for example four nets are positioned on either side, the space between membrane and stator is separated into five equal parts The dis¬ tance between equal charges is reduced to 1/5 and the force between membrane and stator thereby increases 25-fold In this way relatively large movements having an amplitude up to 50 mm or more can be obtained

When the device is used for pumping of gas or liquid which is not electrically conductive, the space between membrane and stator can be used as a pumping chamber Connecting tubes and valves as required may be of conventional kinds This embodiment offers a simple and cost efficient advanta¬ geous solution

Designs of this kind can be especially useful for pumping of air and other gases whereby an important advantage is that the device of the invention in itself is not sensitive to contaminations, condensates and the like The device can therefore be used for example with heat exchangers for air and gases Figure 2 shows mainly in cross-section a membrane pump having a force machine according to the invention Two thin plates, 2, 9 which serve as stators have a number of perforations 39-40 In connec¬ tion to the perforations there are membranes 31 , 32, 33, 34 preferably made from rubber or other suit¬ able flexible material In the embodiment shown in the figure the stators 2, 9, comprise circular discs and the perforations 39, 40 and the membranes 31 , 32, 33, 34 are ring-shaped In order to make the function of the membranes possible, the nets between membrane and stator, which in figure 1 are shown as two connected nets 7, 8, in this embodiment shown in figure 2, split up in two parts both an outer ring 37 and a middle part 38 between which there is a space in which the valve membranes can move

Figure 2 shows the device in a working situation where the middle part 6 is moving to the right in the figure in the direction which has been marked by an arrow The gas which is present in the space be¬ tween the movable body 6 and its membrane and the stator 9 is then compressed The flexible mem¬ brane 31 is forced towards the stator 9 and the openings to the inflow channel 35 are closed by the membrane 31 Due to the overpressure in the pumping chamber the membrane 33 of the outflow channel 36 opens, and the gas flows out from the pumping chamber through the openings 40 On the opposite side of the movable body 6 the space in the pumping chamber expands, and gas is suctioned in through the openings 39

The movement which is generated by the device can also be transferred to one or more rods or the like members which are mounted on to the membranes, and by this in known ways be connected to outer devices whereby for example a pumping chamber can be arranged electrically insulated from the driv¬ ing motor and be used for pumping of electrically conductive liquids In various embodiments the de¬ vice can be used for many different purposes where it can substitute for electrical motors or coils with movable cores, and also be used as a vibrator

Claims

1. Force machine for obtaining a to and fro motion characterised therein that it comprises a frame (3), wherein there are two with each other parallel stators (29) and between the stators one to each stator corresponding and with it parallel arranged and with respective stator electrically connected membrane (19, 20), a device (6) which firmly connects the membranes (19, 20) mechanically with each other, so that the membranes are at a constant distance from each other, and devices to vary the electrical po¬ tential of the respective pair of stator and membrane.

2. Device according to claim 1 , characterised therein that the membranes (19, 20) are connected to each other by means of an intermediate body (6) having essentially the same cross-section as the membranes in their extension in the plane.

3. Device according to claim 2, characterised therein that the intermediate body (6) has a low weight per volume, preferably less than 40 kg/m³.

4. Device according to any of the preceeding claims characterised therein that between the mem¬ branes (19, 20) and stators (2, 9) of a pair there is arranged one or more electrically conductive nets (7, 8) or the like by which the space between the membrane and stator is divided into several essen¬ tially equal parts.

AMENDED CLAIMS

[received by the International Bureau on 21 October 1997 (21.10.97); original claim 1 amended; remaining claims unchanged (1 page)]

1 Force machine for obtaining a to and fro motion characterised therein that it comprises a frame (3), wherein there are two with each other parallel stators (29) and between the stators one to each stator corresponding and with it parallel arranged and with respective stator electrically connected membrane (19, 20), a device (6) which firmly connects the membranes (19, 20) mechanically with each other, so that the membranes are at a constant distance from each other, and devices to vary the electrical potential of the respective pair of stator and membrane, so that to and fro motion is obtained by repelling forces between equal electrical charges

2 Device according to claim 1 , characterised therein that the membranes (19, 20) are connected to each other by means of an intermediate body (6) having essentially the same cross-section as the membranes in their extension in the plane

3 Device according to claim 2, characteπsed therein that the intermediate body (6) has a low weight per volume, preferably less than 40 kg/m³

4 Device according to any of the preceeding claims characterised therein that between the membranes (19, 20) and stators (2, 9) of a pair there is arranged one or more electrically conductive nets (7, 8) or the like by which the space between the membrane and stator is divided into several essentially equal parts