US1568290A - Roller eccentric - Google Patents

Description

v 1,568,290 G. s. MORISON I ROL ERECCENTRIc Jan. 5, 1926.

Fi led Augusi 2, 1923 IIIIIIIIIIIIIIIIIII' the following is Patented Jan. 5 1926.

enonen smrjn MOBISON, or-rrr'rsnnaen, PENNSYLVANIA.

' ROLLER ECCENTRIC.

Application filed August 2, 1923. Serial No. 655,376.

To all whom. it may concern:

Be it known that I, GEORGE SMITH Monr- SON, a subject of the King of Great Britain, and at present a resident of Pittsbur h, in the county of Allegheny and State of Tennsylvania, have invented a new and useful Improvement in Roller Eccentrics, of which a specification.

This invention relates to means for translating a rotary motion of one member into an eccentric motion of another member. More articularly it relates to the translation of motion from a rotar driven shaft to a circular member surroun ing the driven shaft and eccentrically moved thereby in relation thereto.

The objects of the invention comprise the translation of motion from a rotary driving shaft having a normally fixed, axis to an eccentrically movable surrounding member, without toothed gears, without sliding contact surfaces, by means of true circular rollers in contact respectively with the driving shaft and the eccentrically moving driven member, and adapted tobe revolved about t e driven shaft, thus producing a true roller eccentric. At the same time, by means of the resulting eccentric movement of he outer member or ring, or b means of the=revolu-' tion of the rollers a out the shaft, 'a very rapid rotation of the driving shaft may be translated into a comparatively slow reciprocating motion,,or into rotation of another member at a slower spe'ed.- Other objects will be apparent to those familiar with the art from a consideration of the following drawings and specifications.

Referring to the drawings Fig. I shows an elevation and'partial sectlon of one embodiment of my invention, the roller eccentric bein a lied to drivin a vertically reg PE g ciprocating s aft; Fig. 2 is a partial vertical central section on-the line IIII of Fig. 1;

Fig; 3 is a partial vertical section on the line III'III of Fig. 4 of a modified form of the invention, showing the roller eccentric applied as the pinion of an epicyclic gear arrangement, and driving also by way of illustration a laterally extending shaft or arm; Fig. 4 is a partial cross line IV-IV of the device illustrated in Fig. 3, with additional frame members shown; Fig. 5 is a diagrammatic. view of a modified form wherein rollers having two body portions of different diameters are used, this proximately diametricall section on the a view being a section on the line V-V of Fig. 6; and Fig. 6 is an .elevation and partial section on the line VIVI of Fi 5.

Referring to Figs. 1 and 2, a sha 1 is mounted with suitable bearings in a frame 2- upon a base 3. This shaft, which will hereafter be referred to as the driving shaft, is

itself driven by' any suitable form of prime mover, as for example a turbine, electric motor, etc. Between the bearings the shaft carries two collars 4 and 5, and in the space between these collars three cylinders or rollers, 6, 7 and 8, are spaced around the shaft, and bear upon thereto, as illustrated inFig. 1. The rollers 7 and 8 have central pins (or trunnions) 9, which are engaged by connecting links 10 on each side. 1 The pins 9 may be fixed in the rollers, and rotatable in the link, or vice versa, it being necessary for the rollers to be free to rotate on their respective axes with respect to the link, the function of which is simply to maintain them in their relative spaced-apart position with respect to each other. The two rollers 7 and 8 are preferably of'the same size, while the roller 6 is preferably the largest of the three. The arrangement, however, may be reversed, and two large rollers and one small one used.

Surrounding the three rollers 6, 7 and 8,

is a ring member 11, having a' circular it in parallel axial relation rollers-constantly bearing against it at some pgi'nt of their periphery, the three rollers ing positively spaced apart, and an outer ring bearing upon the outer peripheries of the three rollers at points respectively apopposite the points of contact of the rol ers with the drivmg shaft, and one of the rollers being larger than the other two, positively cally with respect to the driving shaft 1.

The eccentric mounting of the ring with respect to the driving shaft producesa space between the face of the groove 12 and the periphery of the driving shaft 1 which space is widest at one point, and decreases in width in opposite circumferential directions or vice "versa, results in positlonmg the ring 11 eccentri i of the shaft, in

from the widest point. For example, referring to Fig. '1, the space between the shaft 1 and the face of groove 12 is widest on the line of centers of the shaft and ring, on the upper side of the driving shaft, on that portion of the line marked X; and narrowest on the lower portion of the line of centers, marked Y, diametrically opposite on the other side of the shaft. The space between the periphery of the shaft and the inner face of the ring gradually symmetrically and uniformly narrows from the widest point X as measured on any exten sion of a radius of shaft 1, as such a radial line is revolved in either direction around the center of the shaft 1 from coincidence with the portion of the line of center marked X to coincidence with the portion thereof marked Y. The larger roller 6 is adapted' to be positioned approximately at the point of greatest width of the space between 1 and 12, as illustrated inFig. 1, and movement of the roller 6 in either direction, in that space, without movement of the ring 11, has a wedge-like effect, and results in a compression of the roller 6 between the driving shaft and outer ring.

Attached to the outer periphery of the ring 11 is a ri 'd arm 13, connected by a pin 14 to a heel crank lever 15, attached by a pin 16 to an extension 17 from the frame. Beyond the pin 14 the lever has a free arm 18, to the end of which by a pin 19 may be attached a vertical shaft or link 20, as illustrated in Fig. 1.

The operation of this embodiment of my invention is as follows: The driving shaft 1 being suitably driven in clockwise direction, referring to Fig. 1, causes the rollers 6, 7 and 8 to rotate in counter-clockwise direction on their own axes, and they being free to move, revolve or roll about the shaft 1 on the track 12, in the direction of rotation the same spaced relation relative to each other, all three revolving about the driving shaft 1 as a center, in clockwise direction.

The outer peripheries of the rollers are in contact with the inner face 12 of the ring 11, but as the ring 11 can not rotate with respect to its center, in consequence of its being held against any such movement by means of the attached arm 13, the result is that the rollers 6, 7, and 8 revolve around the driving shaft 1, simply rolling upon the inner periphery of the ring 11. In elfect they simply roll around the driving shaft in the direction of its rotation fast enough to prevent a slipping contact therewith, and on the ring 11 as a track, all r'olling members rotating on their own axes at exactly the same peripheral speed.

The travel of the rollers of different sizes about shaft 1 imparts to the ring 11 an eccentric movement. The path of travel of the center of the ring 11, or of any point thereon will be a circle with a radius equal to the distance from the axis of the driving shaft 1 to the center of the ring 11, this distance being constant. The center of the ring 11 (i. e. of the path 12 therein) and the axes of rollers 6, 7 and 8.revolve about the axis of shaft 1 in concentric circles.

Obviously. this resultant eccentric movement of the ring 11 may be utilized in various ways for imparting motion, including an epicyclic motion, to various mechanisms. For example in Fig. 1 the arm 13 carried by the ring 11 is applied to the lever 15, fulcrumed at 16, and attached at its free end to a shaft 20, which it is desired to reciprocate. When the shaft 1 is driven clockwise it tends to drive the roller 6 into the narrowing or wedge-like space at the right of the vertical line of center X of the arrangement shown in Fig. 1. There is produced a wedge-like gripping of the large roller 6 between the driving shaft 1 and the inner periphery 12 of the ring 11. The ring being freely suspended with reference to the shaft 1, this gripping pressure is immediately translated in equal degree also to the smaller rollers 7 and 8. The resulting pressure is such that I have found that theshaft does not slip in contact with the rollers, or the rollers in contact with the ring, in spite of the fact that the rollers run in an oil bath, but the shaft imparts a true rolling movement to the rollers which causes them and the ring 11 to revolve about it without lost motion. Even if the rollers are not an absolutely accurate fit, as for example, if they have become slightly worn, the above described result follows, because the larger roller merely moves slightly further into the tapered space provided for it, and then automatically wedges, transferring pressure in equal proportion to the other two rollers, exactly as in the case where the three rollers are. of maximum size to fit within the space in the relation illustrated. In Figs. 3 and 4 I have illustrated a modification in that instead of three rollers I use 4. These are preferably arranged in two pairs of rollers of the same size in each pair, but of different size as compared to the other pair, as for example, two larger rollers 6, and two smaller rollers 7 and 8. The two smaller rollers 7 and 8 are connected by a link 25, and the two larger rollers 6 by a link 26, the roller being free to rotate with respect to the said link, as are the rollers 7 and 8 with respect to the link 10 of Fig. 1. In this modification it will be apparent that the two large rollers (Pare not positioned at the maximum width of the space between the driving shaft 1 and the ring 11, but are at approximately equal distances from the line of maximum width, one on each side of that line, and are positively connected together and spaced apart to maintain their respective ositions.

The wor ing of this arrangement is not different in principle fromthat above described with reference to Fig. 1. When the shaft 1 is driven clockwise the roller 6* at the right is gripped between the shaft and the surrounding ring 11. The resulting pressure is translated in substantially equal degree from the gripped roller 6 to the rollers 7 and 8, and there is in effect a three-point gripping and drive, resulting in the imparting of an eccentric movement to the ring 11 as the rollers run around the rotating shaft 1, as will'be obvious. If the rotary direction of the shaft 1 is reversed the roller 6 at the left will be gripped, the rollers will rotate and travel in the other direction with the shaft and consequently the ring 11 will be moved eceentrically by the gripped roller and the two smaller rollers, exactly as in the other case. One of the large rollers therefore is in position to be gripped (and consequently the other rollers 7 and 8" are equall gripped) upon rotation of the driving s aft in either direction. I

In connection with Figs. 3 and 4 I have illustratedv a different and alternative way of translating the eccentric movement of riphery o resulting gear or pinion with another ring the ring 11 to 'power purposes. This consists in applying teeth 30 to the outer pethe ring 11', and surrounding the 31, having internalteeth 32 of the same pitch, and of atleast two teeth greater in' number. The eccentric movement of the ring 11 will thus drive the outer ring 31, whichis mounted on bearings 33 carried by shaft 1, causing it to rotate on a true geometric axis,--i.- "e. the axis of shaft 1.- Power may be derived from the driven rotating ring 31 by any suitable means, as for example it may be used to drive a belt, or

may ave frictional contact with additional rolls, or teeth may 'be provided on the outer face of the ring 31, to drive other gears meshing therewith. a

In connection" with Fig. 3, I have also illustrated a rigid arm 13' carried by the ring 11 which may be used for driving any desired machinerypas illustrated and described in connection with Fig. 1, above. In that case, however, some other means must be used for preventin free rotation of the eccentrically driven ring 11.. Otherwise it would not necessarily drive a surrounding member, such as ring 31 of Fig. 3, but might itself rotate on its own axis sufiiciently to accommodate the meshing of'teeth resulting from the epicyclic movement of the eccentrically driven ring. I have used the word free in connection with permissive rotation of the eccentrically moving ring fixed axis, be prevented from all rotation.

It is only necessary that the eccentrically moving ring be sufficiently fulcrumed against free rotation to insure a driving ac;- tion on the outer ring of fixed axis by reason of the meshing of the teeth of the two rings. That is to say, referring to Fig. 3, it is necessary to insure-rotation of" ring 31 rather than rotation of ring 11. 'But to .do this there may still be some rotation of ring 11, as will be obvious. In one e1nbodiment of this invention which I have built, the teeth of ring engaging the teeth of a rotatable ring corresponding to 31, also engage corresponding teeth of a third ring positioned besidering 31, but held in fixed ment results in a xed amount of forced rotation of ring 11, as it travels in epicyclic movement about the inner periphery of the fixed outer ring, while at the .same timedriving the rotatable outer ring by the epicyclic movement and meshing of .the teeth of the two movable rings.

It will be understood that the ep'icyclic gear arrangement illustrated in Fig. 3 may be applied to the ring 11 of Figs. 1 and 2, thearm 13 being omitted, if desired.

Referring to Figs. 5 and 6 the modification illustrated comprises .a driving shaft 1", in contact with three rollers 6 7" and 8 each of which has three body portions, two outer portions being of the same and Iposition. Such arrange- 11 in addition tolarger diameter than an intermediate cylindrical' body portion. In effect, there are two rollers u on one axis. The smaller intermediate diameters of these rollers are adapted to bear upon the inner face 12* of the ring 11", and the larger diameters to middle portions of the rollers, and the body portions of larger diameters being arranged ateach end of each roller, so as to form in effect retaining flanges on each side of the ring 11 Power may be derived by attaching a rigid arm 13" to the eccentrically driven ring 11", as will be readily understood, and this moving arm may beused for the driving of any desired mechanism as above described. Y

It will be apparent that in each of the forms illustrated, there may be secured a very substantial speed reduction. For example, referring to Fig. 1, supposing the driving shaft 1 to be ten inches mcircumference in the path of the rollers, and the inner face 12 of the ring 11 upon which the outer portions ofthe rollers bear to be .to drive associated apparatus.

n n l n eighty inches in circumference, there wlll be one complete cycle of eccentric movement of Y the ring 11 for each nine revolutions of the driving shaft. By varying. the comparative dimensions of the driving shaft, rollers and ring, the speedreduction may be varied within a considerable range. By applying the roller eccentric as a pinion to drive an epicyclic gear, as shown in Fig. 3,01 by using the two-diameter rollers as shown in Figs. 5 and 6, a .much greater reduction may be attained. I have constructed successful machines having a reduction of 17000 to 1.

Since as above pointed out, the rollers are caused to revolve about the driving shaft when that member is rotated, a suitable axially aligned associated shaft, or other rotatable element, may be driven in thesame direction but at a lower speed by direct at tachment to the link 10 of Fig. 1, the links 25 and 26 of Fig. 3 or the link 10 of Fig. 5. I have not attempted to illustrate or de scribe in this application all of the many applications and modifications that may be made of this invention. I have illustrated three arrangements for imparting an eccentric motion to a ring, from a rotating driving shaft by means of rolling members of different diameters positioned between the driving and driven member. Incidentally I have illustrated two ways of utilizing resulting eccentric movement of the ring I have also pointed out that the revolutions of the rollers between the driving shaft and eccentrically driven ring may be utilized for direct rotation of associated mechanism, and particularly shafts or other rotary members having a common axis with the driving shaft. I believe I am the first to make such an arrangement of mechanical elements, and therefore am entitled to broad patent protection upon it, regardless of the use that may be made of the movement produced. i a r Although I have illustrated and described truly cylindrical rollers for furnishing the contact between the driving shaft and driven ring, I may, in certain cases, substitute spheres for cylinders. In the case of spheres, instead of linking them together with pins as illustrated in the case of rollers, which however may be done even with spheres or balls, I prefer to use connecting cages, similar to those now known in connection with ball bearings. The linking arrangement illustrated may be varied, as for example in Fi 1 the larger and one of the smaller rollers may be linked together and the other allowed to run free,'

and in Fig. 3 a larger and a smaller roller on each side may be linked,-instead of the two larger and'two smaller.

I prefer to enclose the rollers and driving shaft in a casing so that the rollers may have a constant oil bath. This does not recular rolling members being of different rcspectlve diameters.

2. Mechanism for producing an eccentric motion of a ring member comprising a circular rotatably driving shaft, an internally circular ring surrounding said shaft and held against free rotation, circular rolling members positioned between the shaft and ring and bearing against the shaft and ring,

two of said circular rolling members being respectively of different diameters, and a rigid connection between two of the sald c1rcular rolling members.

3. A roller eccentric comprising a circular rotary driving shaft, an internally circular ring surrounding said shaft and held against free rotation, a series of circular rolling members comprising at least two of different respective diameters arranged in the space between said shaft and ring, each of said circular rolling members being in contact with the shaft and ring and positively spaced apart from every other rolling member.

4. A roller eccentric comprisinga circular rotary driving shaft, an internally circular ring surrounding said shaft, circular rolling members arranged in the space between said shaft and circular ring and in contact with said shaft and ring, two of said rollers being of different respective diameters, links connecting two of said circular rollingmembers and maintaining their spaced relation, and means preventing free rotation of the rin 5. A roller eccentric comprising a circular rotary driving shaft, an internally circular ring surrounding said shaft, circular rolling members arranged in the space between said shaft and circular ring and in contact therewith, two of said rollers being of different respective diameters, means preventing free rotation of the ring, and means to apply the eccentric movement of the ring to drive connected mechanisms.

6. Mechanism for producing an eccentric motion, comprising a rotatably mounted driving shaft having a fixed axis, circular rolling members arranged around and in contact with the driving shaft, one roller being of greater diameter than one of the other rollers, two of the circular rolling members being positively spaced apart by :1. connecting member. a circular ring surrounding the rolling members and driving shaft and having, its inner circular periphery bearing against the outer peripheries offthe' said rollers, the ring being free to move eccentrically but held against free rotation.

7. A power-translating device comprising a circular rotatable driving shaft, a circular ring surrounding said shaft, a series of circular rolling members positioned between the shaft and the ring and bearing against said shaft and ring, the rolling members'being adapted to revolve about the shaft, some of the rolling members being of different-respective diameters.

8. A power-translating mechanism comprising a circular rotatable driving shaft, a circular ri g surrounding the driving shaft, a series of circular rolling members adapted to revolve about the shaft and positioned between and in contact with the driving shaft and interior face of the ring, two of said circular inembers being of different respective diameters, and gear'teeth on the outer face of the ring whereby to engage and drive associated apparatus by epicyclic movement of said ring.

'9. A power-translating mechanism comprising a circular rotatable driving shaft, a circular ring surrounding the driving shaft, circular rolling members adapted to revolve about the shaft and positioned between and in contact with the driving shaft and interior face of the ring, some of said circular members being of different respective diameters, and means to engage and drive associated apparatus by eccentric movement of said ring.

10. A power-translating mechanism comprising a circular rotatable" driving shaft, :1 circular-ring surrounding the driving shaft, circular rolling members adapted to. revolve about the shaft and positioned between and in contact with the driving shaft and interior face of the rin some of said circular members being of iiferent respective di ameters, and means to engage and drive associated apparatus by revolution of said circular rolling members.

11. A power-translating device comprism a circular rotatable driving shaft, a circu ar ring surrounding said shaft, 0. series of circular rolling members positioned between the shaft and the ring and bearing against said shaft and ring, the rolling members being adapted to revolve about the shaft, some of the rolling members being of different respective diameters, and a member connecting two of the circular rolling members.

12. A device for translating power, comprising a circular rotary driving shaft, a circular ring surrounding the shaft, circular roller members positioned between the shaft and inner circular periphery of the ring hearing against said shaft and ring and adapted to revolve about the shaft, some of said roller members being of different respective diameters, means to prevent free rotation of a second ring surrounding the first ring having a fixed axis and having teeth on its inner circular periphery adapted to mesh with and be engaged by the teeth of the inner ring, there being a greater number of teeth on the the ring, teeth on the outer face of the ring,

inner periphery of the outer ring than on i the inner ring, whereby the outer ring may be rotated by eccentric epicyclic movement of the inner ring. i

I "13'. Power-translating mechanism comprising a circular rotary driving shaft of fixed axis, a circularring surrounding the shaft, circular roller members positionedbetween and bearing against the shaft and ring and adapted to revolve about the shaft, some of the rollers being of different respective diameters, means to hold the ring against free rotation, and a member attached to a pair of said rollers and adapted to be driven around the axis of said shaft by'revolution of said rollers.

14. A power translating device comprising an inner circular member, an internallycircular ring member surrounding the inner member and eccentrically positioned with respect thereto, a series of intermediate rolling members positioned between and engaging said inner member and ringand adapted to revolve about the inner member, certain ones of saidroller members being of different respective diameters.

In testimony whereof, I sign my name.

GEORGE SMITH MORISQN.

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