US3512905A

US3512905A - Rotary device

Info

Publication number: US3512905A
Application number: US532355A
Authority: US
Inventors: Jorgen Frederik Waldorff
Original assignee: Danfoss AS
Current assignee: Danfoss AS
Priority date: 1965-03-05
Filing date: 1966-03-07
Publication date: 1970-05-19
Anticipated expiration: 1987-05-19
Also published as: DK117880B; GB1102997A; CH448751A; NL6602656A; SE311286B; DE1528998A1

Description

May 19, 1970 I J. F. WALDORFF ROTARY DEVICE 2 Sheets-Sheet l Filed March 7, 1966 May 19, 1970 J. F. WALDORFF 3,512,905

ROTARY DEVICE Filed March 7, 1966 2 Sheets-Sheet 2 United States Patent ()flice Int. (:1. Ftl4c 1/06 US. Cl. 418-61 11 Claims ABSTRACT OF THE DISCLOSURE A rotary device for interacting with a fluid having a casing enclosing an annular element. An inner element is disposed internally and eccentrically of the annular element. The annular element has an inner surface having alternating convexities and concavities and the inner element has an outer surface having alternating convexities and concavities. The number of convexities on the annular element excedes the number of convexities of the inner element. A shaft, rotatably mounted in the casing, mounts one of said elements. Guide means permit the center of the outer of the elements to define a revolution of a circular path about the axis of the shaft for each fraction of a revolution of said shaft. The concavities and convexities, respectively, of said inner element are engageable with the convexities and concavities, respectively, of the annular element and the distance between a substantially opposed concavity and convexity of the annular element is at least equal to the distance between substantially opposed concavities of the inner element. Thus upon rotation of the shaft, at any given moment, only some of the concavities and convexities, respectively, of the inner element are in engagement with only some of the convexities and concavities, respectively, of the annular element. This enagement motivates one of the two elements in the circular path of the center thereof. An inlet conduit and an outlet conduit are defined through the casing..A first plate is mounted for rotation of its center about the axis of the shaft and has a face constituting a common wall of chambers defined by spaces between the concavities and the oonvexities of the elements.A conduit is defined through the first plate and communicating with one of the chambers and including an opening on the other face of said first plate. A second plate is mounted in the casing and having a face contacting the other face of the first plate. A conduit is defined through this second plate and communicates with one of the conduits defined through the casing and has an opening on the face of the second plate. The opening on the first plate and the opening on the second plate are disposed so that upon rotation of the shaft they periodically come into and out of at least partial registry and thereby communication between the aforementioned one of the chambers and the prior mentioned one of the conduits defined through the casing is established when said openings are in at least partial registry and terminated when the openings are out of at least partial registry.

This invention relates to a rotary device for interacting with a fluid. More specifically, this invention relates to such a rotary device including means for communicating between chambers in the device and an inlet or an outlet of the device.

The rotary device of the invention includes a casing enclosing an annular element, and an inner element disposed internally and eccentrically of the annular element. The annular element has an inner surface having alternating oonvexities and concavities. Similarly, the inner element has an outer surface having alternating convexities and Patented ,May 19, 1970 concavities. For each of the elements, since the concavities and convexities alternate, the number of concavities is equal to the number of convexities. However, for the sake of convenience and simplicity of expression hereinafter in the specification and in the claims, sometimes only the concavities or only the convexities will be referred to. The number of the convexities of the annular element exceeds, by at least one, the number of the convexities of the inner element. Specific embodiments of the rotary device of the invention include gear pumps and gear motors Using gear terminology, one skilled in the art may refer to; the annular element as a spur internal gear, in view of the internally disposed alternating concavities and convexities, and to the inner element as a spur external gear', or toothed star member in view of the externally disposed alternating concavities and'convexities.

The rotary device of the invention further includes a shaft rotatably mounted in the casing. The shaft mounts either the annular element or the inner element for rotation with the shaft. Guide means are provided which permit the center of the element which is not mounted on the shaft to define a revolution of a circular path about the axis of the shaft for each fraction of a revolution of the shaft.

The concavities and convexities, respectively, of the inner element ,are engageable with the convexities and concavities, respectively, of the annular element. The distance between a substantially opposed concavity and convexity of the annular element is at least equal to the distance between substantially opposed concavities of the inner element. Accordingly, upon rotation of the shaft, at any given moment only some of the concavities and convexities, respectively, of the inner element are in engagement with only some of the convexities and concavities, respectively, of the annular elementQThe expression substantially opposed refers to the closest approximation to perfect opposition. Thus, the expression a substantially opposed concavity and convexity of the annular element refers to any concavity and convexity of the annular element which come at least as close to perfect opposition as any other concavity and convexity of the annular element. The expression substantially opposed concavities of the inner element is defined in like manner. The engagement of the inner element with the annular element motivates the element which is not mounted on the shaft in the circular path in which it is guided by the above referred to guide means.

An inlet conduit and an outlet conduit, for fluid, defined through the casing are provided. Because of the above described configurations of the annular and inner elements, spaces exist between the conavities and convertities thereof. These spaces serve as fluid chambers. A first plate is mounted for rotation of its center about the axis of the shaft. This plate is disposed in such a manner that a face thereof constitutes a common wall of the chambers. A conduit or passage is provided through the plate to communicate with one of the chambers. A second plate is fixedly mounted in the casing and disposed so that a face thereof contacts the face of the first plate which is opposed to the face serving as a common wall of the chambers. A conduit or passage is provided through the second plate, which conduit or passage communicates with either the inlet conduit or the outlet conduit.

The respective-conduits of the first and second plates each have an opening at their respective contacting faces. Since the center of the first plate follows a circular path about the axis of the shaft, the opening on its face also follows a circular path. The opening on the face of the second plate is so disposed that this circular path intersects it. During the intersecting of the two openings they are in at least partial registry and, thereby, communicaoais establ shed. bet eeath c ambe an t fi t-9 external power source such as an electric. motor, the

device isaforrn of gear pump... ,Generally, a conduit.system as .hereinabove described is ,provide d for each .of the chambers- Furthermore, generally, ,each of thefihambers i ,provided with two conduit systems as hereinabove described one of the'conduit systems communicating with the inlet conduit and the pther with the outletconduit. Furthermore, two commonconduits or-headers are provided. One of these com- .rnon conduits serves as a common link betweeneach of the'conduits of the second plate intended ultimately to communicate with the. inlet conduit and the outlet conduit, and the other common conduit serves similarly with respect to the conduits of the second plate intendedultimately to communicate wvith the outlet conduit.

When the second plate is provided with a second conduit in order that means for communicating with-both the inlet and the outlet conduit exist, the opening of the second conduit on the face of the second plate contacting a face of the first plate is disposed in the circular path followed by the opening of the first plate. However, the two openings on the second plate are sufiiciently spaced apart so that only one at a time is in at least partial registry with the opening on the. first plate. Therefore, alternatingly, communication is established. between the chamber and the inlet conduit or the outlet conduit and, accordingly, fluid is permitted into the chamber and then is permitted to leave the chamber. Thus, the arrangement described serves as distribution valve means.

Since a fluid is communicating with the chambers at only one side of'the'elements in the'arrangement above described, that side being namely the side at which't'he plates are disposed, an unbalanced pressure is exerted on theelements.'Acc0rdingly, for smooth, eflicient operation, the need sometimes arises to counteract or balance this unbalanced pressure. Accordingly, there is provided a conduit'communicating between one of the common conduits and pressure exerting means displaceably mounted in a wall of the casing opposite the face of the second plate having the opening or (Ypenings and at a sideof the elements opposite the'side' thereof at which the plates are disposed. The pressure exerting mean is displaceable toward the elements under the influence of fluid pressure transmitted through the conduit communicating between the common conduit and the pressure exerting means. Thereby, a fluid pressure is exerted against the elements a direction to counteract tthe fluid pressure on the elements at theoppo site ide thereof. Generally, one of these arrangements is provided with respect to each of the Q I m du Ina preferred arrangement, a third plate is provided. This platefis mounted at the side of the elements opposite the side thereof atwhich the firstand second plates are disposed, whereby the. third plate constitute a sec- 0nd common rwallof the -chambers.

It is preferred that the above referredto openingson the disc's each'belinythe form of a radial'gr oove. When the second disc is provided with a pair of conduits for a chamber, "generally the two radial grooves on the second disc will be separated'by a circumferential distance at t means there were used, two concentricallyarranged rptational slide valve elements, of which one was fixed to the inner element of the gearpump and the other to the annular element of the gear pump. The number of control openings in one slide valve element corresponded to the number of teeth of theinner element and the number, of 'controL-openings' in the other slide valve element corresponded to thenumber of teeth of, the annular element. Consequently, in operation, a commutator effect was" attained. The-arrangement of the present -invention provides distributorvalve means which is simpler in construction than the distributor valve means of the prior art and which also requires shorter conduits and can more easily be fabricated.

A specific embodiment of the invention will now be described by reference to the drawings, in which:

FIG; 1 is a longitudinal section of a-ge'ar pump'according to the invention; e

FIG; 2 is a cross section'- along the line -A-A' in FIG. "3 is across section along the" line B-B in FIG. Ifin which, however, the parts of FIG. 4 have been omittedf 1 I FIG. 4 is a plan view of the two major elements of the gear pump with a shaft and rivets shown in section;

' The casing of the gear'pump consists of a front wall member 1, a cylindrical side wall member 2*and a back wall merhb'erd, which are interconnected by means of screws 5 and sealed by meansof sealing rings (not shown A' main shaft 6 is 'rotatably mounted ir'r-the casing by means of a bearing 7 in' the front wall member 1 and a bearing 8 in a plate 3.' The periphery of the plate'3 is inserted between the cylindrical side wall member 2 and the back wall member 4 and, thereby, the plate 3 is fixedly mounted in the casingI The shaftf6 is provided with a slotted portion of conventional'con struction on which is mounted" for rotation with the shaft an inner element 10 having alternating concavities and convexities or" teeth on its outer peripheral surface. The teeth of the inner element 10 are' in engaging relationship with the alternating co'ncavities' and convexities or teeth on the inner peripheral surface of an annular element 11. Two plates 13 and 14 are fixedly mounted on the opposed faces of the outer element 11 by means of rivets 12. Spaces or chambers 19 exist between the concavities and convexit ies or teeth of the elements 10 andll. ,j

The plates 13 and 14 at'their peripheries are provided with recesses 15 each in the form of a sector of a circle.

The recesses 15 correspond in number to the number of the screws 5. On .the screws .5 are rotatably mounted cylinders or rollers 16 which intermesh with the recesses 15. The diameter of each of the cylinders 16 is smaller than thediameter of each of the recesses 15,-whereby the cylinders 16 in followingan arcuate path along the walls of the recesses 15 cause the center M of the, annular element 11 to follow a circular path E about the center M of the shaft 6 (FIG.. 3). The centerM of the shaft 6 is also the centersof the inner element 10. The-centers of .the two plates 13 and 14 follow a like path as they are mounted fixedly on the annular element 11. The recesses 15 in combination with the rollers 16 constitute guide means, and this guide means is further described in my application entitled Guide Means filed on the same date as this application, reference to which is hereby made. I The plates lfl and 3 act together'as distributor valve means by virtue of conduits or passages provided through them and by virtue of the motion of the platei1'4, which motion, as noted above,"is exactly like that or the annular element 11. Specifically, plate 14 is' provided with conduits or passages therethrough each constituting a bore 18 communicating with a radial groove 17 which radial groove constitutes the opening of a conduit at a face of the plate 14, and plate 3 is provided with two sets of conduits therethrough, one set consisting of radial grooves 20 communicating with an annular common conduit or groove 23 and radial grooves 21 communicating with an annular common conduit or groove 26. An inlet conduit 24 provided through the back wall member 4 of the casing communicates with common conduit 23, and an outlet conduit 27 through the back wall member 4 of the casing communicates with common conduit 26. Communication between radial grooves 20 and common conduit 23 is through bores 22 and communication between radial slots 21 and common conduit 26 is through bores 25.

The spaces between the concavities and convexities of the inner and annular elements constitute chambers 19. Each of the radial grooves 17 follows a circular path. Each of the sets of

radial grooves

20 and 21 is in the circular path of a corresponding one of the radial grooves 17. Accordingly, the radial groove 17 periodically comes into at least partial registry with one of the

radial grooves

20 and 21. Only one of the

radial grooves

20 and 21 at a time is in at least partial registry with the radial groove 17 because the radial grooves 20-and 21 are circum-.

ferentially spaced apart from one another by a distance at least equal to the width of the radial groove 17. Communication is therefore alternatingly established between the chambers 19 and the inlet and

outlet conduits

24 and 27.

Counteracting means are provided to counteract or balance the pressure exerted by the fiuid at the side of the elements and 11 at which the

plates

14 and 3 are disposed. The counteracting means includes

conduits

28 and 30 communicating respectively between radial slots and annular groove 29 and between radial slots 21 and annular groove 31. Pressure exerting means are provided consisting of annular members 'or rings 32 and 33 slid ably mounted in

annular grooves

28 and 29 and plate 34. Annular members 32 and 33 are slidable in the

annular grooves

28 and 29 in the direction of the axis of the shaft 6. Similarly, plate 34 is slidably mounted in a recess in the front wall member 1 of the casing whereby it is slidable in the direction of the axis of the shaft 6. The conduits 28 and are in ultimate communication with the

common conduits

23 and 26, respectively, since the

radial grooves

20 and 21 are in communication with the

common conduits

23 and 26, respectively. Fluid pressure transmitted through the

conduits

28 and 30 displaces the annular members 32 and 33, respectively, toward and into a bearing relation against the plate 34. The plate 34 is in turn urged against the plate 13 and thereby the fluid pressure on the other side of the

elements

10 and 11 is counteracted.

Viewing the device from the end at which the shaft 6 protrudes, when the shaft 6 is rotated counterclockwise, the device operates as a pump, sucking large quantities of a liquid through the inlet conduit 24 and discharging the liquid through the outlet conduit 27. On the other hand, when it is desired to usethe device as a gear motor, the shaft 6 is not connected to a driving means, a fluid under pressure is supplied to the inlet conduit 24 and the fluid imparts a relatively large moment of rotation to the shaft 6 and the shaft 6 rotates in the aforementioned direction; the fluid discharges through the outlet conduit 27. By reversing the direction of flow through the device by making the outlet conduit the inlet conduit and vice versa, the direction of rotation of the shaft is reversed.

The invention is not to be construed as limited to the particular forms disclosed herein, since these are to be regarded as illustrative rather than restrictive. Thus, for example, distributor valve means as described. herein can be placed on either side of the chambers 19, of which one distributor valve means is arranged to cooperate with the inlet conduit and the other distributor valve means is arranged to cooperate with the outlet conduit. Furthermore, the annular element rather than the inner element may be mounted on the shaft, in which arrangement the inner element would be guided so that its center would describe a circular path about the center of the shaft. Also, either the inner element or annular element may be so arranged as both to rotate with the shaft and also to have its center guided in a circular path about the center of the shaft.

What I claim and desire to secure by Letters Patent is:

1. A rotary device for interacting with a fluid comprising a casing enclosing an annular element, an inner element disposed internally and eccentrically of said annular element, said annular element having an inner surface having alternating convexities and concavities and said inner element having an outer surface having alternating convexities and concavities, the number of said convexities of said annular element exceeding the number of said convexities of said inner element, a shaft rotatably mounted in said casing and mounting one of said elements, guide means permitting the center of the other of said elements to define a revolution of a circular path about the axis of said shaft for each fraction of a revolution of said shaft, the concavities and convexities, respectively, of said inner element being engageable with the convexities and concavities, respectively, of said annular element and the distance between a substantially opposed concavity and convexity of said annular element being at least equal to the distance between substantially opposed concavities of said inner element, whereby, upon rotation of said shaft, at any given moment only some of the concavities and convexities, respectively, of said inner element are in engagement with only some of the convexities and concavities, respectively, of said annular element and said engagement motivates the aforementioned one of said elements in said circular path of said center thereof, an inlet conduit'and an outletconduit defined through said casing, a first plate mounted for rotation of its center about the axis of said shaft and having a face constituting a common wall of chambers defined by spaces between said concavities and said convexities of said elements, a conduit defined through said first plate and communicating with one of said chambers and including an opening on the other face of said first plate, a second plate fixedly mounted in said casing and having a face contacting said other face of said first plate, a conduit defined through said second plate and communicating with one of said conduits defined through said casing and including an opening on said face of said second plate, the opening on the first plate and the opening on the second plate being so disposed that upon rotation of said shaft they periodically come into and out of at least partial registry and thereby communication between said one of said chambers and said one of said conduits defined through said casing is established when said openings are in said at least partial registry and terminated when said openings are out of said at least partial registry.

2. A rotary device according to claim 1, in which each of said openings is a radial groove.

3. A rotary device according to claim 2, further comprising a second conduit defined through said second plate and communicating with the other of said conduits defined through said casing and including a second radial groove on said face of said second plate, said second radial groove being circumferentially spaced from the first mentioned radial groove on said face of said second plate so that upon rotation of said shaft said groove on said first plate periodically and alternatingly comes into at least partial registry with one of said first and second grooves whereby said inlet and outlet conduits alternatingly communicate with said one of said chambers.

4. A rotary device according to claim 3, in which said spacing of said grooves of said second plate is at least equal to the width of said groove of said first plate.

5. A rotary device according to claim 4, in which said 7 element which is mounted on said shaft is said inner element.

6. A rotary device according to claim 5, in which said chambers equal in number the number of said convexities of said annular element and a set of said conduits having grooves as openings is provided for each of said chambers, and there is provided a first common conduit communicating with all of the conduits which communicate with the inlet conduit and a second common conduit communicating with all of the conduits which communicate with the outlet conduit.

7. A rotary device according to claim 6, further comprising counteracting means, said counteracting means including a conduit communicating between one of said common conduits and pressure exerting means displaceably mounted in a Wall of said casing opposite said face of said second plate and at a side of said elements opposite the side thereof at which said plates are disposed, said pressure exerting means being displaceable toward said elements under the influence of fluid pressure transmitted through said conduit communicating between said one of said common conduits and said pressure exerting means to exert said fluid pressure against said elements to counteract the fluid pressure on said elements at said side of said elements at which said plates are disposed.

8. A rotary device according to claim 7 in which there is provided two of said counteracting means, one of said counteracting means including a conduit communicating with said first common conduit and the other of said counteracting means including a conduit communicating with said second common conduit.

9. A rotary device according to claim 8, further comprising a third plate, said third plate being mounted at the side of said elements opposite the side thereof at which said first and second plates are disposed and constituting a second common wall of said chambers.

10. A rotary device according to claim 9, in which each of said pressure exerting means includes an annular member, said annular member being axially displaceably mounted in an annular groove in said wall of said casing and a pressure plate interposed between said Wall of said casing and said third plate, and each of said conduits of said counteracting means communicates with a respective one of said annular grooves, whereby fluid pressure transmitted through said conduits of said counteracting means urges said annular members against said pressure plate, said pressure plate thereby being urged against said third plate.

11. A rotary deivce according to claim 1, in which said first plate is fixed to said other of said elements, whereby said first plate defines the same path as said other of said elements and, accordingly, the opening on said first plate defines a revolution of a circular path for each fraction of a revolution of said shaft, and the opening on said second plate is disposed in said circular path of the opening of said first plate.

References Cited UNITED STATES PATENTS 2,823,616 2/1958 Toyoda.

2,998,783 9/1961 Lee.

3,026,809 3/1962 Anderson et al.

3,136,261 6/ 1964 Eckerle et a1.

3,270,683 9/1966 McDerrnOtt.

3,272,142 9/1966 Easton 103130 3,309,999 3/1967 Patterson 103-130 ROBERT M. WALKER, Primary Examiner