US3695789A

US3695789A - Balancing mechanism for fluid translating device

Info

Publication number: US3695789A
Application number: US27733A
Authority: US
Inventors: Birger F Jansson
Original assignee: JI Case Co
Current assignee: Case LLC
Priority date: 1970-04-13
Filing date: 1970-04-13
Publication date: 1972-10-03
Anticipated expiration: 1989-10-03

Abstract

A fluid translating device having a rotor rotatably mounted within a bore in a camblock that is supported within a housing. The rotor is spaced from the bore to define an annular space and has plates extending from opposite ends thereof with the end portions of the side plates being in overlapping spaced relationship with the opposed surfaces of the camblock. The opposed surfaces of the camblock have a plurality of circumferentially spaced recesses formed therein with each of the recesses communicating with the annular space through a slot. Thus, fluid being translated between inlet and outlet ports flows in the spaces between the end portions of the plate and the adjacent surfaces of the camblock and seals the annular space, while some of the pressure fluid is received in the respective recesses to maintain the camblock in a centered position between the respective end portions of the plates. In one embodiment, the recesses are arcuate and located on a common diameter greater than the diameter of the bore. In an alternate embodiment, the recesses are arcuate and one end of each recess is closer to the surface of the bore than the opposite end while the camblock has cutout portions extending from the bore surface and from the outer surface, so that all portions of the plate end portions are exposed to the fluid. In a further embodiment, the recesses are substantially longitudinal and extend chordally of the center of the bore. The camblock also has surfaces adjacent the housing opening which are beveled from a center point to produce substantial line contact between the housing opening and the camblock.

Description

United States Patent J ansson [54] BALANCING MECHANISM FOR FLUID TRANSLATING DEVICE [72] Inventor: Birger F. Jansson, Racine, Wis. [73] Assignee: J. I. Case Company [22] Filed: April 13, 1970 [21] Appl. No.: 27,733

[52] US. Cl. ..418/75, 418/107, 418/133, 277/96 [51] Int. Cl ..F0lc 21/00, F03c 3/00, F04c 27/00 [58] Field of Search ..418/75, 76, 77, 78, 79, 80, 418/81, 82,133, 31, 107, 108; 277/96;

Primary Examiner-Carlton R. Croyle Assistant Examiner-John J. Vrablik Attorney-Dressler, Goldsmith, Clement & Gordon [57] ABSTRACT A fluid translating device having a rotor rotatably [4 1 Oct. 3, 1972 mounted within a bore in a carnblock that is supported within a housing. The rotor is spaced from the bore to define an annular space and has plates extending from opposite ends thereof with the end portions of the side plates being in overlapping spaced relationship with the opposed surfaces of the carnblock. The opposed surfaces of the carnblock have a plurality of circumferentially spaced recesses formed therein with each of the recesses communicating with the annular space through a slot. Thus, fluid being translated between inlet and outlet ports flows in the spaces between the end portions of the plate and the adjacent surfaces of the carnblock and seals the annular space, while some of the pressure fluid is received in the respective recesses to maintain the carnblock in a centered position between the respective endportions of the plates.

In one embodiment, the recesses are arcuate and located on a common diameter greater than the diameter of the bore. In an alternate embodiment, the recesses are arcuate and one end of each recess is closer to the surface of the bore than the opposite end while the carnblock has cutout portions extending from the bore surface and from the outer surface, so that all portions of the plate end portions are exposed to the fluid. In a further embodiment, the recesses are substantially longitudinal and extend chordally of the center of the bore.

The carnblock also has surfaces ad acent the housing opening which are beveled from a center point to produce substantial line contact between the housing opening and the carnblock.

14 Claims, 13 Drawing Figures PATENTEDUBT 3 m2 59g )Bzrger f l/fr SHEET 1 OF 2 1155022 GHQ 5 BALANCING MECHANISM FOR FLUID TRANSLATING DEVICE BACKGROUND OF THE INVENTION The present invention relates generally to fluid devices and, more particularly, to a balancing mechanism for relatively movable parts of the fluid device.

Fluid translating devices of the type commonly referred to as vane-type pumps are well known in the art, as exemplified by [1.8. Pat. No. 3,187,676. Generally these fluid translating devices include a housing having an opening therein which slidably receives and supports a camblock. The camblock is generally supported for vertical movement within the housing to vary the output, as well as the direction of flow of fluid through the pump.

The camblock has an internal bore with a rotor rotatable about a fixed axis in the bore. The rotor has a plurality of radially extending slots, each of which slidably supports a vane having a free end held in engagement with the internal surface of the camblock bore by suitable biasing means. The camblock and rotor cooperate to define an annular space which is in communication onopposite sides thereof with inlet and outlet ports formed in the housing.

In order to enclose the opposite ends of the annular space between the camblock and the rotor, the rotor normally has a pair of circular plates secured to opposite ends thereof with the end portions of the plates being in overlapping relationship with an adjacent portion of the camblock.

Thus, rotation of the rotor within the bore or workin g chamber will cause the vanes to translate fluid from the inlet port to the outlet port across the annular space or zone defined between the camblock and the rotor. The particular spacing between the camblock and the rotor and the eccentricity of the bore axis and the rotor axis will cause the pressure of the fluid to be increased as the fluid is translated from the inlet to the outlet port.

In fluid pumps of this type, difficulties have been encountered in maintaining an effective fluid seal between the plates rotating on opposite sides of the fixed camblock while still eliminating metal-to-metal contact between the adjacent surfaces of thecamblock and the side plates. Heretofore, it was considered necessary to machine the adjacent surfaces of the camblock and the side plates, as well as the opposite ends of the rotor, to very close tolerances in order to prevent metal-to-metal contact between the adjacent surfaces. While the machining to very close tolerances may be accomplished at considerable expense, there is still another difficulty in that the spacing between the two surfaces must be sufficient to allow free rotation of the rotor and plates. Furthermore, in a reversible pump,

the camblock must be readily movable in the housing.

Thus, it has been found that if the spacing is too small, it may result in metal-to-metal contact between the adjacent surfaces and will also prevent adjustment of the camblock, within the pump housing. If the spacing between the "surfaces is too great, excessive leakage from the annular space will be encountered and there is a tendency for the camblock to tilt relative to the side plates and result in a jamming of the camblock within the housing opening to prevent movement of the camblock to accommodate any misalignment between the rotor and bore axis. This again may result in metalto-metal contact.

In view of these difliculties, there still remains a need for a simple and efiicient manner of sealing the ad jacent surfaces of the camblock and the plates and yet allowing sufficient clearance between the two surfaces to accommodate misalignment of the parts during operation and adjustment of the camblock.

SUMMARY OF THE INVENTION The present invention contemplates a variable volume fluid translating device which has one of the relatively movable elements floatingly supported with respect to the other of the relatively movable elements. The floating support for the one element relative to the other element is accomplished by forming recesses on the fixed element which are in communication through slots with the fluid translated through the device to maintain a predetermined spacing between adjacent surfaces of the respective elements.

Stated another way, the present invention contemplates a fluid translating device of the type having a housing supporting a camblock within an opening and having a rotor supported for rotation about a fixed axis within a working chamber defined in the camblock. The annular zone between the. camblock and the rotor is sealed by a pair of plates forming part of the rotor and extending adjacent opposite surfaces of the camblock with the spacing between the plates being greater than the axial length of the camblock, so as to produce small spaces or gaps between the adjacent surfaces of the camblock and the plates. The camblock surfaces have circumferentially spaced recesses formed therein which are in communication with the annular zone or space through slots defined in the camblock surfaces.

With the above arrangement, pressured fluid within the annular zone is received into the recesses on opposite ends of the camblock and tends to maintain the camblock in a centered position relative to the spaced plates. Furthermore, by utilizing the recesses and the substantially unrestricted flow into the recesses from the annular space, as the spacing between the adjacent surfaces of the camblock and the plate on one side is decreased and the opposite side is increased, the pressured fluid received into the recesses, which is or has a pressure substantially equal to that of the pressured fluid within the annular zone, will at all times tend to maintain a true centered position of the camblock relative to the spaced plates and prevent metal-to-metal contact between the adjacent surfaces of the rotor assembly and the camblock assembly.

In one embodiment of the present invention, the opposed surfaces of the camblock have circumferentially spaced arcuate recesses which are located on a common diameter concentric with the center of the camblock bore. In an alternative embodiment, the camblockhas a ring portion adjacent the bore which has arcuate recesses with opposite ends of each of the recesses being located on spaced diameters concentric with the bore. In this embodiment, the ring portion has circumferentially spaced cutouts or notches extending from the outer end inner perimeter of the ring portion and located between each of the adjacent ends of the respective recesses, so that each radial portion of the adjacent rotating plate will be lubricated several times during each cycle of revolution. In a still further embodiment, the recesses extend chordally of the bore and are defined in raised portions of the surface, so that again the entire adjacent rotating surfaces will be lubricated several times during each cycle of revolutron.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF DRAWINGS FIG. 1 of the drawings discloses a horizontal sectional view of a fluid translating device having the present invention incorporated therein;

FIG. 2 is an end view of the camblock assembly forming part of the fluid translating device of FIG. 1;

FIG. 3 is an enlarged fragmentary view of the camblock and rotor assembly shown in FIG. 1;

FIG. 3a (appears with FIG. 4a) is a pressure-area diagram for the flow of fluid through the gap shown in FIG. 3;

FIG. 4 is a view similar to FIG. 3;

FIG. 4a is a pressure-area diagram for the flow of fluid through the gap shown in FIG. 4;

FIG. 5 is an end view of the cam ring portion of the camblock showing a modified form of the invention;

FIG. 5a is a sectional view taken generally along line Sa-Sa of FIG. 5;

FIG. 5b is a sectional view taken generally along line Sb-Sb of FIG. 5;

FIG. 50 is a sectional view taken generally along line 5c-5c of FIG. 5;

FIG. 6 is a view similar to FIG. 5 showing a further modified form of the camblock;

FIG. 6a is a sectional view taken along line 6a-6a of FIG. 6; and

FIG. 6b is a sectional view taken along line 6b-6b of FIG. 6.

DETAILED DESCRIPTION While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail several specific embodiments, with the understanding that the present disclosure is to be considered an exemplification of the principles of the invention and is not intended to limit the invention to the embodiments illustrated.

FIG. 1 of the drawings discloses a fluid translating device 10 of the type generally referred to as a reversible flow, vane-type, variable volume pump. The fluid translating device or pump 10 includes a housing assembly 12, a camblock assembly 14 and a rotor assembly 16. The housing assembly 12 takes the form of a pair of

pieces

18 and 20 extending from opposite ends of a centerpiece 22 and are interconnected by a plurality of bolts 23. The

pieces

18 and 20 cooperate with the centerpiece 22 to define an opening or cavity 24 having a pair of

ports

26 and 28 located on opposite sides thereof.

The opening 24 of the housing 12 receives and slidably supports the camblock assembly 14 which includes a camblock 30 and a cam ring 32. The cam ring 32 has a central bore 34 which is in communication at opposite sides of the respective ports 26 through

passageways

36 and 38, respectively, extending through the camblock and the cam ring. While the camblock assembly is shown as being formed of two pieces, it may readily be formed in a single piece and will hereinafter be referred to as the camblock with the ring being referred to as a ring portion.

The rotor assembly cooperates with the bore or working chamber 34 defined in the camblock 14 to produce an annular space or zone 40 which defines a lap space for fluid from one of the ports, 26, 28, to the other of the ports, 26, 28. For this purpose, the rotor assembly 16 includes a rotor 42 splined at 44 to a shaft 46, which is rotated about the fixed axis within the housing on

bearings

48 and 50 received in bores in the

end pieces

18 and 20. The rotor 42 has a plurality of circumferentially radially extending slots 52, each of which receives and slidably supports a vane 54, the outer end of which is in contacting engagement with the surface defined by the bore 34 by suitable biasing means not shown).

The rotor assembly 16 further includes a pair of

plates

56 and 58, commonly referred to as side plates, that are supported for rotation with the rotor 42 adjacent the opposite ends thereof by being splined to the shaft 46. Each of the

circular plates

56 and 58 has an end portion which is in overlapping juxtaposed relation to the adjacent surfaces of the cam ring 32. Thus, the

adjacent surfaces

60 and 64 of the

respective side plates

56 and 58, respectively, cooperate with the opposed surfaces 62 and 66 of the ring portion 32 to substantially enclose the opposite ends of the annular space 40.

As was indicated above, the fluid translating device 10 is of the reversible and variable volume type, which is accomplished by having the camblock assembly 14 vertically shiftable within the opening 24 to rearrange the eccentric relationship between the axis of the bore 34 and the axis of the shaft 46 to thereby reverse the direction of flow of the pump. Assuming that the axis of the bore 34 is below the axis of the shaft 46 and the shaft is rotated in a counterclockwise direction, fluid will be translated from the port 28 to the port 26 and the pressure of the fluid will be increased as it is translated through the lap space defined by the annular space or zone 40 between the ports.

As was indicated above, in order to translate fluid between the

ports

26 and 28, it is necessary to produce relative rotation between the adjacent surfaces 60 through 66. To accommodate such relative rotation of the adjacent surfaces, it would be desirable to produce as much spacing between the surfaces as possible to thus eliminate any metal-to-metal contact to prevent wear on the adjacent surfaces. On the other hand, in order to maintain the efficiency of the pump at its highest level, it is necessary that the spacing between the adjacent surfaces of the plate and the ring portion be at a minimum to insure that the fluid is all translated between the ports.

The problem becomes even more acute when the rotor assembly 16 is rotated very rapidly and the pressure of the fluid is increased substantially between the inlet and the outlet ports. For example, when the fluid is received into the inlet port at an elevated pressure and the pressure thereof is increased to approximately 2,000 psi, the optimum spacing between the movable member and the fixed member becomes extremely critical. In such instances, it is necessary to insure that there is a spacing between the adjacent surfaces at all times and yet the spacing should not be so great as to allow a large quantity of fluid to escape from the annular space.

According to the present invention, the optimum condition is achieved by having the axial length of the ring portion 32 of the camblock slightly less than the axial spacing between the

adjacent surfaces

60 and 64 of the

plates

56 and 58 to allow a minimum amount of pressured fluid flow from the annular space or zone 40 into each of the gaps and maintain the gaps substantially equal. This will maintain the camblock centered between the

respective surfaces

60 and 64 and the spacing between the adjacent surfaces is at all times sufficient to prevent the shearing of the oil film between the respective surfaces, thereby avoiding any substantial temperature increases of the fluid or the metal.

The above is accomplished by forming a plurality of recesses at spaced locations on one of the adjacent surfaces of the ring portion or the plates and placing each of these recesses in communication with the annular space 40 through slots defined in the associated surface.

Referring particularly to FIGS. 1 through 4, the first or outer member defined by the camblock is floatingly supported adjacent the rotor assembly 16 and the gap between the adjacent surfaces, for example, surfaces 64 and 66, remains substantially constant by forming a plurality of circumferentially spaced recesses 70 in the surface 66 with each of the recesses being in individual communication with the annular space or zone 40 through a slot 72. In the embodiment illustrated, in FIGS. 2, 3, and 4, the surface 66 has six such recesses or pockets 70 which are equally spaced circum ferentially of the ring 32, with each of the recesses being arcuate. The arcuate recesses are formed on a common diameter which is greater than the diameter of the bore 34.

The opposite surface 62 (not shown) of the ring portion 32 of the camblock will also have recesses and slots of identical configuration and location, shown in FIG. 2. The recesses or pockets 70 are arranged so that three of the pockets in each of the surfaces are adjacent each of the two

ports

36 and 38. With this arrangement, when fluid is being translated between the two ports, the fluid in the low-pressure port will be received in six pockets located on opposite ends of one-half of the ring portion of the camblock, while the high-pressure port will be in communication with the remaining six pockets on the other half of the ring portion.

As was indicated above, in the'optimum condition, the gaps or flow paths, generally designated by the reference numeral 74, in FIGS. 3 and 4, are equal in volume so that opposite ends of the cam ring portion 32 of the camblock are equally spaced from the respective

adjacent surfaces

60 and 64 of the

side plates

56 and 58. In this condition, the limited amount of flow will not only maintainthe camblock centered, but will also produce a fluid seal for the annular zone or lap space 40. If, for some reason, or other, this optimum or equlibrium, centered condition of the camblock is disturbed, the spacing between one end surface of the camblock and the adjacent surface of the plate will become greater while the spacing between the rotor assembly and the opposite end of the camblock will become smaller. If the spacing between the adjacent surfaces is decreases sufficiently, the oil film or flow of fluid through the gap 74 will be interrupted because of the shearing forces encountered by the film of fluid.

However, the above condition of interruption of fluid flow is eliminated by producing the recesses in one of the adjacent surfaces and placing the recesses in communication with the fluid being translated. With this arrangement, the resistance to movement of the adjacent surfaces towards each other is increased nonlinearly as the spacing is decreased. Furthermore, considering the opposite end of the camblock, as the spacing between the adjacent surfaces is increased, the force on the camblock from the flow of fluid will be substantially decreased. This phenomenon will be more readily understood by considering FIGS. 3a and 4a, which, respectively, show the pressure-area diagram across the gaps 74 for the two conditions illustrated in FIGS. 3 and 4. FIG. 3a shows that the initial pressure drop across the radial area A, between the inner surface of the bore 34 and the inner edge of the recess is approximately one-half of the pressure in the annular space or working chamber 40. However, the pressure drop across the radial area A defined between opposite edges of the recesses or pockets 70 will be very minimum because pressured fluid is constantly being supplied through the slots 72. The remainder of the pressure drop will occur along the area A which is between the outer edge of the ring portion 32 and the outer edge of the recess 70.

Considering now FIG. 4a, which shows the pressure area diagram across the reduced gap 74 of FIG. 4, it will be appreciated that the amount of flow through the gap 74 will be considerably less than through the gap shown in FIG. 3, while the amount of fluid received into the recesses 70 will substantially be the same for both conditions. Stated another way, the ratio of fluid flow through the gap versus the flow of fluid into the recesses decreases as the size of the gap decreases. Thus, the pressure drop across the area A will be small and the pressure drop across the area A will also be very minimal resulting in a major portion of the pressure drop occuring in the area A From a comparison of FIGS. 3a and 4a, it will be appreciated that the total forces produced on one surface FIG. 4 condition) will be substantially greater than the total force produced on the second surface (FIG. 3 condition). The total resultant force tending to center the camblock will, therefore, increase non-linearly or at a greater than the decrease in the size of the gap or space. Stated another way, when the clearance or gap 74' is large, as shown in FIG. 3a, the pressure drop across the areas A, and A will be substantially equal with substantially no pressure drop occurring in the area A When the clearance or gap 74 is very small, the flow resistance from the recesses or pockets 70 will be substantially increased and, combined with the significant fluid flow through the slots 72 into the pockets 70, will maintain the pressure of the fluid within the pocket 70 at a level considerably more than one-half the pressure of the fluid within the annular space or zone 40. Thus, the pressure drop along the area A;, is considerably greater than the pressure drop along the area A,. With such an arrangement, it is virtually impossible to decrease the spacing or clearance between the adjacent surfaces of the rotor assembly and the camblock assembly to a point where the fluid film will be sheared and cause an overheating of the adjacent surfaces of metal. Furthermore, the operation of the fluid seal and self-centering device of this type will not be dependent upon having a substantial pressure drop from the annular space 40 to the outer edge of the camblock 14, because the relative pressure increase on one side of the rotor at a rate greater than the decrease of pressure at the opposite side. This will be true, regardless of the level of pressure of the fluid in the annular space. This arrangement is of considerable importance in preventing metal-tometal contact when the pump is in a neutral condition and the pressure of the fluid in not increased as it is passing between the respective ports.

By eliminating the metal-to-metal contact, or even having the spacing between the adjacent surfaces of the rotor assembly and the camblock assembly maintained above a predetermined minimum, the friction losses in this area of the pump are substantially eliminated and the various parts need not have the extremely close tolerances heretofore considered necessary.

As wasindicated above, the camblock is generally capable of being shifted vertically relative to the axis of the rotor assembly 16, so as to vary the output, as well as the direction of flow of fluid through the pump. Generally, this is accomplished by forming the opening 24 of a rectangular configuration and having the opposed vertical outer walls or surfaces of the camblock assembly 14 (the surfaces which extend perpendicular to the axis of the ports 26 and 28) in contacting engagement with the adjacent surfaces of the opening thereby eliminating any possibility of movement of the camblock assembly 14 axially between the inlet and outlet ports.

However, such an arrangement creates a problem in that any tendency for the rotor to become misaligned relative to the axis of the bore 34 will have a tendency for the camblock to likewise become misaligned by this amount. Such a condition could readily cause the camblock to become jammed within the opening 24 to thereby prevent the free movement of the camblock between the side plates and also prevent vertical shifting of the camblock to adjust the flow through the pump. Such a condition could again cause metal-tometal contact between the adjacent surfaces of the camblock assembly 14 and the rotor assembly 16 resulting in ultimate failure of the pump.

However, according to another aspect of the present invention, this problem is eliminated by producing vertical line contact between the adjacent walls or surfaces of the camblock and the opening 24. This is accomplished by producing a high point 100 on each of the surfaces 102 of the camblock 14, which are located adjacent the

respective ports

26 and 28. The point contact 100 is obtained by producing a taper or bevel in opposite directions from the center of the camblock. Thus, by tapering or beveling the respective surfaces, a comparatively small surface or substantial line contact will be produced between the surfaces 102 and the adjacent surfaces of the opening, which will be along the lines 100. It will be appreciated that the beveling or tapering of the respective surfaces 102 is greatly exaggerated in FIG. 1 and in actual practice the taper will be relatively small, for example, on the order of 0.015 inch per inch.

In order to prevent fluid from leaking through the small space produced between the adjacent walls of the opening in the housing and the camblock assembly, the camblock assembly preferably has a groove formed therein with an O-ring 112, or other suitable sealing means received in the groove. It will be appreciated that the line contact between the housing assembly 12 and the camblock 14 will eliminate the possibility of having the camblock become jammed in the housing opening.

A slightly modified embodiment of the present invention is disclosed in FIG. 5. Since the only difference between the embodiment shown in FIG. 2 and that shown in FIG. 5 is the arrangement of the recesses, like reference numerals have been applied and the suffix a has been added. In the embodiment illustrated in FIG. 5, the recesses 700 are again arcuate in configuration and each recess is formed to the same radius. However, in this embodiment, the recesses are tilted relative to the center of the bore 340 so as to laterally offset the centers of the respective equal radii from the center of the bore 34a. Such an arrangement will result in having one edge of the recess 70a spaced a greater distance from the center of the bore 340 than the opposite end of each of the recesses. Also, in the embodiment illustrated in FIG. 5, the ring has a plurality of opposed cutouts or notches and 122, respectively, extending from the outer edge and the inner edge of the surfaces 66a and 62a (not shown). The inner edges or bases of the outer cutouts or notches 120 are located on a common diameter with all of the outer edges of the recesses or pockets 70a, while the outer edges or bases of the inner cutouts or notches 122 are located on a common diameter with the inner edges of the opposite end of the respective recesses or pockets 700. With such an arrangement, the entire radial or overlapping area of the

end plates

56 and 58, which is in juxtaposed relation to the surface 66a and the opposite surface 62a (not shown) of the ring portion of the camblock will be exposed to fluid several times during each cycle of rotation of the plates relative to the cam ring. This will insure a proper lubrication of the side plates and will prevent any possibility of thermal expansion due to lack of lubrication of the rotating surface.

A further modified embodiment of the invention is shown in FIG. 6 in which the surface 66b (as well as the opposite surface of the cam ring portion, not shown) has a polygonal or hexagonal raised portion with each of the sides of the polygon having a linear recess 70b and each of the recesses or pockets 70b communicating through slots 7212 with the annular area or zone defined between the camblock and the rotor assembly. It will be appreciated that, in the alternative embodiment shown in FIG. 6, each area of the adjacent rotating side plate will be exposed to fluid for purposes of lubrication several times during each cycle of rotation. This will necessarily result, because the chordal arrangement of the recesses or pockets 70b will have corresponding segments of each of the pockets located at a different diameter than an adjacent segment. Furthermore, the substantially planar sides of the polygonal raised portion 130 will produce inner and outer cutout portions at circumferentially spaced locations on op- 9 posite sides of the raised portion 130. Of course, the upper surface of the raised portion .130 will be the surface which is in juxtaposed relationship to the adjacent surfaces of the

plates

56 and 58.

The major advantage of sealing the areas between the rotor assembly and thecamblock assembly in the manner described above is that the hydrostatic effect of the seal will not be affected by changes in speed of rotation of the rotor assembly relative to the camblock assembly. Furthermore, the present invention allows for the manufacture of pumps at a reduced cost, because the tolerances of the various parts can be increased considerably.

While the fluid seal arrangement of the present invention has been described in connection with a fluid translating device or pump, it is readily apparent that the principle of the present invention could be incorporated to other fluid devices. For example, the selfcentering and sealing feature has particular utility in other hydraulic components, such as hydraulic cylinders, axially sliding valve spools, rotating valve spools, and components where a combined rotating and sliding movement is required. For example, a valve spool could readily be self-centered and sealed within a valve bore by placing circumferentially spaced recesses in either the valve spool or the bore and placing these recesses in communication with high-pressure fluid supplied to the valve.

What is claimed is:

1. A fluid translating device comprising a housing having a rectangular opening therein; an inner member and an outer member cooperating to produce an annular space with said members being relatively rotatable, said outer member having a rectangular peripheral surface cooperating with said opening, one of said members including portions having surfaces in overlapping spaced relation to adjacent surfaces of the other of said members to substantially enclose said annular space; means defining circumferentially spaced recesses in the surfaces of one of said members, said recesses being in individual communication with saidannular space, at spaced locations so that pressured fluid in said annular space will be received in said recesses to maintain said other member centered between said portions and flow of fluid between said surfaces will produce a fluidseal for said annular space; and means defining line contact along opposed portions of said peripheral surface and said opening, said line contact being centrally spaced and parallel to said surfaces of said outer member.

2. A fluid translating device as defined in claim 1, in which said recesses are arcuate and equally spaced about said annular space.

3. A fluid translating device as defined in claim 1, in which said recesses are chordally arranged and equally spaced about said annular space.

4. A fluid translating device comprising a housing having an opening therein and opposed inlet and outlet ports communicating with said opening, a camblock supported for movement in said opening and having a bore; a rotor rotatable about a fixed axis in said bore and cooperating with said bore to define an annular space; a pair of plates rotatable with said rotor, said plates having end portions in overlapping relation with respective opposed surfaces of said camblock with said camblock having an axial length between said surfaces which is less than the spacing between said plates to produce limited flow paths from said annular space betweenisaid end portions and the adjacent surfaces of said camblock; and means for producing circumferentially spaced elongated recesses and slots in said camblock surfaces, said recesses being spaced from said bore and said slots placing each of saidrecesses in communication with said annular space, whereby fluid translated between said ports will be received in said recesses and maintain said surfaces spaced from said end portions and the fluid in said flow paths will seal the annular space from the opening in the housing.

5. A fluid translating device as defined in claim 4, in which said recesses are arcuate and are located on a common diameter greater than the diameter of said bore.

6. A fluid translating device as defined in claim 4, in which said surfaces each have a polygonal raised portion with a recess defined in each leg of said polygonal raised portion.

7. A fluid translating deviceas defined in claim 4, in which said recesses extend chordally of the center of said bore.

8. A fluid translating device as definedin claim 4, including the further improvement of means for producing line contact between at least a portion of adjacent surfaces of said opening and said camblock to accommodate relative movement of said surfaces.

9. A fluid translating device as defined in claim 4, in which said recesses are arcuate and have opposite ends located on different diameters.

10. A fluid translating device as defined in claim 9, in which said camblock has a ring portion defining said opposed surfaces, said ring having inner and outer ends, the further improvement of means defining inner and outer notches in said surfaces, respectively, extending from said ends and terminating between adjacent ends of each pair of recesses, the inner notches having bases located on a common diameter with inner edges of one end of each of said recesses and the outer notches having bases located on a common diameter with outer edges of the opposite ends of said recesses, whereby the overlapping portions of said plates are exposed to fluid for lubrication during rotation.

11. A fluid translating device comprising a housing having an opening therein with inlet and outlet ports on opposite sides of said opening; a camblock supported in said opening and having a bore defining a working chamber; said working chamber communicating with inlet and outlet ports in said housing; a rotor rotatably supported within said working chamber and cooperating with said camblock to define an annular zone, said rotor having end plates rotatable therewith and extending in juxtaposed overlapping relation to opposite ends of said camblock, said camblock having a length between said surfaces which is less than the spacing between adjacent surfaces of said plate; and means defining line contact between the surface of said opening and said camblock, whereby to accommodate relative movement of said camblock in said opening.

12. A fluid translating device as defined in claim 11, the further improvement of means producing a plurality of spaced recesses in said end surfaces of said camblock, said recesses being spaced from and communicating with said annular zone, whereby fluid in said annular zone will flow into said recesses and maintain said camblock centered between said plates.

13. A fluid translating device as defined in claim 11, in which said opening and said camblock are rectangul2 14. A fluid translating device as defined in claim 13, in which the opposed sides of said camblock are beveled from the center toward opposite ends to lar and said line contact is defined between the side of 5 produce Said lme Contact said opening having said ports therein.

Claims

1. A fluid translating device comprising a housing having a rectangular opening therein; an inner member and an outer member cooperating to produce an annular space with said members being relatively rotatable, said outer member having a rectangular peripheral surface cooperating with said opening, one of said members including portions having surfaces in overlapping spaced relation to adjacent surfaces of the other of said members to substantially enclose said annular space; means defining circumferentially spaced recesses in the surfaces of one of said members, said recesses being in individual communication with said annular space, at spaced locations so that pressured fluid in said annular space will be received in said recesses to maintain said other member centered between said portions and flow of fluid between said surfaces will produce a fluid seal for said annular space; and means defining line contact along opposed portions of said peripheral surface and said opening, said line contact being centrally spaced and parallel to said surfaces of said outer member.

4. A fluid translating deviCe comprising a housing having an opening therein and opposed inlet and outlet ports communicating with said opening, a camblock supported for movement in said opening and having a bore; a rotor rotatable about a fixed axis in said bore and cooperating with said bore to define an annular space; a pair of plates rotatable with said rotor, said plates having end portions in overlapping relation with respective opposed surfaces of said camblock with said camblock having an axial length between said surfaces which is less than the spacing between said plates to produce limited flow paths from said annular space between said end portions and the adjacent surfaces of said camblock; and means for producing circumferentially spaced elongated recesses and slots in said camblock surfaces, said recesses being spaced from said bore and said slots placing each of said recesses in communication with said annular space, whereby fluid translated between said ports will be received in said recesses and maintain said surfaces spaced from said end portions and the fluid in said flow paths will seal the annular space from the opening in the housing.

7. A fluid translating device as defined in claim 4, in which said recesses extend chordally of the center of said bore.

8. A fluid translating device as defined in claim 4, including the further improvement of means for producing line contact between at least a portion of adjacent surfaces of said opening and said camblock to accommodate relative movement of said surfaces.

13. A fluid translating device as defined in claim 11, in which said opening and said camblock are rectangular and Said line contact is defined between the side of said opening having said ports therein.

14. A fluid translating device as defined in claim 13, in which the opposed sides of said camblock are beveled from the center toward opposite ends to produce said line contact.