HK1112368A - Orbiting valve for a reciprocating pump - Google Patents

Description

Orbiting valve for reciprocating pump

This application claims priority to U.S. provisional application 60/610013 filed on 9, 15, 2004.

Technical Field

The present invention relates to valves for use in inlet and outlet port arrangements (porting of intake and exhaust) in reciprocating pumps, including vacuum pumps and compressors, and more particularly in multi-cylinder pumps such as swash plate or nutating or rocking piston pumps or pumps having axial pistons arranged about a central axis.

Background

Passive valves such as flapper, poppet or umbrella valves are used in the inlet and outlet arrangements of reciprocating piston pumps. Flapper valves are typically made of thin, flat materials. Stainless steel has been used for high pressure flapper valve applications, while elastomers have been used for small, low pressure flapper valve applications. Poppet valves are typically made of a relatively hard material that is biased against a valve plate using a spring. Umbrella valves are typically made of an elastomeric material and include built-in attachment methods for holding themselves against the valve plate while covering some of the small holes. Each of these passive valve systems is actuated by fluid pressure acting on the valve so that fluid can only pass in one direction.

Passive valve systems are limited by the speed at which they can respond, and are more restrictive and less efficient at higher speeds.

Direct acting valve systems are known. Cardiollo, US 5058485 discloses a linear orbiting ring valve for a hydraulic swash plate pump. White, US 4877383 discloses a direct acting valve such as an orbiting valve for a gerotor device. Us patent 6224349 discloses a direct acting orbit valve for a swash plate pump.

Disclosure of Invention

The present invention provides a direct acting, orbiting valve system for a reciprocating piston pump, including a compressor or vacuum pump, which provides greater pumping efficiency over a higher speed range than is currently suitable for passive valve systems.

The present invention provides intake and exhaust valve functions using a single orbiting valve member to alternately route cylinder ports with separate intake and exhaust ports. In addition, a single orbiting valve member can have port routing for separate pressure and vacuum cylinders connected to the same valve plate of a multi-cylinder machine.

The present invention reduces the ultimate torque required and the frictional losses associated with the orbiting valve member by allowing the orbiting valve member to rotate slightly under static friction conditions that produce a twisting motion that results in a mechanical advantage that more easily separates the static friction attachment surfaces of the orbiting and valve plates than a rotary valve.

In one embodiment of the invention, routing of intake and exhaust is accomplished by interconnecting cylinder ports in the valve plate with intake and exhaust ports in the valve plate using concentric grooves in the orbiting valve. In an alternative embodiment, the present invention provides for the routing of intake and exhaust through discrete, non-concentric groove segments in the orbiting valve member. In this case, the orbit valve is restricted from rotating by the compliant member.

The foregoing and other aspects, such as inventive features, objects, and advantages, of the present invention will become apparent in the following brief description of the drawings, detailed description, and claims.

Drawings

FIG. 1 is a perspective view of a reciprocating pump incorporating features of an embodiment of the present invention;

FIG. 2 is a side view of the pump shown in FIG. 1;

FIG. 3 is a top plan view of the reciprocating pump shown in FIG. 1;

FIG. 4 is a bottom view of the reciprocating pump shown in FIG. 1;

FIG. 5a is a cross-sectional view taken along line 5-5 of FIG. 2;

FIG. 5b is a perspective view of the cross-section shown in FIG. 5 a;

FIG. 6a is a perspective view of the orbiting valve of the pump of FIG. 1 looking into the surface of the valve having two concentric grooves;

FIG. 6b is a plan view of the grooved surface of the orbit valve shown in FIG. 6 a;

FIG. 7 is a perspective view of the valve plate of the pump of FIG. 1 looking into the surface of the valve plate having three cylinders extending therefrom; for ease of illustration, the plate is shown having an approximately square shape, as opposed to its actual circular shape shown in fig. 5a, 5 b;

FIG. 8 is a perspective view of the valve plate shown in FIG. 7 looking into a surface opposite the surface shown in FIG. 7;

FIG. 9 is a plan view of an assembly of components from the pump of FIG. 1, wherein the assembly has a valve plate containing three cylinders, an orbiting valve, and an eccentric interfacing the valve plate with the orbiting valve; for convenience, the orbit valve circumferential projection seen in FIG. 5a is not shown; also for ease of illustration, the valve plate is shown having an approximately square shape, as opposed to its actual circular shape shown in fig. 5a, 5 b; wherein the view is looking toward the motor end of the pump, away from the pump end opposite the motor, and into the surface of the valve plate having three cylinders extending therefrom;

10a-10e are generally the same plan views as shown in FIG. 9, but for added convenience only one cylinder and its associated cylinder port are shown; the figure shows the sequence of the prescribed positions of the rail valve relative to the piston;

FIG. 11 is a partial cross-sectional view along the longitudinal axis of a pump having an alternative embodiment of the present invention with the orbiting valve eccentric of the pump on the opposite side of the valve plate as compared to the placement of the orbiting valve in FIG. 5 a;

FIG. 12a is a plan view of an assembly of components from a pump of the type shown in FIG. 1; this figure shows an alternative embodiment of the invention in which the assembly has a multi-cylinder valve plate, only one cylinder being shown for convenience; a rail valve having a plurality of segmented inlet through ports and a plurality of segmented discharge slots, again only one discharge section being shown for convenience; and an eccentric interfacing the valve plate with the orbiting valve, wherein the view is looking toward the motor end of the pump, away from the pump end opposite the motor, and into the surface of the valve plate having the cylinder extending therefrom;

FIG. 12b is a perspective view of the assembly shown in FIG. 12 a; for convenience, the arm shown in this perspective view as extending from the orbit valve is omitted from the plan view shown in FIG. 12 a;

FIG. 13 is a top perspective view of an orbit valve eccentric of the pump of FIG. 1;

FIG. 14 is an end perspective view of the shaft, orbit valve eccentric, and orbit valve of FIG. 1 assembled together.

Detailed Description

Referring now to fig. 1-5b, a orbiting or oscillating piston compressor or pump 100 has a housing 102. The housing 102 encloses a crankcase volume 104. The pump has some main drive components within the housing. The main drive components within the housing include the shaft 18, eccentric 64, eccentric bearing 62, wobble member 60, and cross-shaped universal joint 56. Two opposing arms of the universal joint 56 are coupled to a connector 59 and the other two opposing arms are connected to a swinging or yoke member 60.

The oscillating member 60 has three arms 74, which are identical to each other. Only one arm 74 is shown. Each arm has a bulbous head 76 at its end.

The pump 100 has three pistons that are identical to each other. Only one piston 14a, 14b is fully shown. Each piston has a piston head 14b and a piston rod 14 a. Each piston rod 14a is hollow and houses a socket half 78. The spherical head 76 of each wobble member is coupled to the piston rod 14a via the socket half 78.

As can be seen in fig. 7 and 9, each piston is associated with a corresponding cylinder 20a, 20b and 20 c. Each cylinder is associated with a cylinder port 28a, 28b, and 28 c. See fig. 7, 8 and 9. The cylinder ports 28a, 28b and 28c each include an elongated cylinder groove port portion 28a ", 28 b", 28c "and a small, central, oval-shaped cylinder through port portion 28a ', 28b ', 28c '. The small oval portion is the only portion of the cylinder port that actually penetrates the valve plate. The center of the UV joint 56 is aligned with the shaft axis 18 a.

During operation of the pump 100, the drive shaft 18 is rotated by the motor 58, the stator of which is secured to the end cap 52, which is secured to the housing 102 via the wall 103 to enclose the orbit valve 16, the orbit valve eccentric 30, the orbit valve eccentric bearing 32, and the counter moment block (counter moment) 54.

When motor shaft 18 rotates, eccentric 64 oscillates oscillating member 60 via bearing 62 and thereby imparts a primarily reciprocating motion to drive rod 14 a. Orbiting valve eccentric 30, acting through orbiting valve eccentric bearing 32, orbits orbiting valve 16 about shaft centerline 18 as it slides relative to valve plate 25. Two concentric grooves 22 and 24 in the orbit valve 16 alternately slide over the cylinder ports 28a, 28b and 28c to provide sequential fluid communication with the inlet port 27 and the outlet port 26. See fig. 9, 10a-10 e. Groove 22 may be referred to as a pressure or exhaust groove, while groove 24 may be referred to as an inlet groove. The dashed lines in fig. 5a, 5b indicate the fluid communication between the drain 26 shown in fig. 9 and the connecting tube 46 shown in fig. 5 a. The incoming fluid passes through port 44 of the damping chamber 48, through port 42 into the crankcase chamber 104, and then through the valve inlet port 27. The arrows in fig. 5a, 5b show the fluid flow direction.

Fig. 5a and 5b show the piston rod 14a in a top dead center position such that the cylinder through port 28a is no longer connected to either the exhaust groove 22 or the intake groove 24.

Referring now more particularly to fig. 10a-10e, the sequence of the orbit valves can be further seen. In these figures, only one cylinder 20a and its associated cylinder port 28a are shown for ease of reference. Also for ease of reference, the projection 16c is not shown. Each of the other cylinders 20b, 20c is subjected to exactly the same sequence, except that the cylinders are 120 ° out of phase with each other. The direction of the orbit valve 16 is indicated by arrow 70 and is counterclockwise, looking at the valve plate 16 from the cylinder side. During this sequence, the angular orientation of the shaft 18 relative to the orbit valve 16 is marked with a darkened area 30 a. Thus, the rotation angle and the position of the piston can be correlated with each other.

In understanding how fig. 10a-10e illustrate the sequencing of the orbit valves, it is important to note that the phase of the orbit valves sequenced by the eccentric 30 relative to the piston is adjusted to be 90 out of phase with the piston motion. At the beginning of the sequence, fig. 10a, the piston is at the Top Dead Center (TDC) position, see fig. 5a and 5 b. The cylinder port 28a does not communicate with the discharge or pressure groove 22 or the intake groove 24. The inlet groove 24 is ready to communicate with the cylinder port 28 a. The center 16a of the orbit valve 16 is shown to move to the left in fig. 10 a. If an "x, y" chart 17 oriented about the centerline of the shaft 18 were superimposed on FIG. 10a, the direction of displacement would be "-x". The amount of displacement is determined by the amount 30b (fig. 13) by which the orbit valve eccentric 30 is offset from the axis center line 18 a. When piston rod 14a is at the top dead center position, center 16a of orbit valve 16 is not moving along the y-axis. The orbit valve center 16a is thus centered vertically with respect to the shaft 18. In the top dead center position, the orbit valve center 16a is located more or less 90 degrees counterclockwise from the top cylinder 20a as shown in FIG. 10 a.

Continuing forward in this sequence, fig. 10b, the piston has traveled half way down cylinder 20a (away from valve plate 25). The cylinder through slot 28 "communicates with the inlet slot 24. Next, fig. 10C, the piston has traveled to the Bottom Dead Center (BDC), the maximum distance from the valve plate 25. The cylinder port 28a does not communicate with the inlet groove 24 or the pressure groove 22. When the piston moves from the BDC position to a position approximately at the center of the upward stroke, the cylinder through port 228' is not in communication with the inlet or exhaust groove. This makes it possible to build up a pressure in the cylinder that is almost equal to the pressure in the discharge channel. Next, fig. 10d, the piston has traveled half way up the cylinder, i.e. in the middle of the lifting stroke and in the maximum compression position. Finally, in fig. 10e, the piston is at 45 ° before TDC. The cylinder port 28a opens to the discharge or pressure groove 22 via a cylinder groove portion 28a ". The relative positions of the other ports 28b, 28c when the piston is 45 deg. before TDC can be seen in fig. 9.

In the above sequence, the orbit valve 16 is not restricted from rotating about its own axis, but because the grooves 22 and 24 are circular, the orbit valve can rotate and orbit, but rotation about its own axis does not affect its operation. Additionally, the combination of the bearing 32 and the friction of the orbiting valve 16 against the valve plate 25 will cause this motion to be predominantly orbital, with only a small, if any, rotation. In addition, the grooves 22 and 24 do not penetrate the orbit valve to form a through space.

The use of a cylinder port having a slotted portion 28a "and a through portion 28 a' is believed to be advantageous over the use of a simple through port. In addition, the use of the inner grooves 22 as the discharge grooves 22 is considered to be advantageous compared to (using) the outer grooves because the surface area forming the inner grooves is smaller than the outer grooves. The smaller area reduces the force on the orbit valve 16 caused by the fluid pressure. However, orbit valve 16 may be configured to use an external groove as a drain.

Another feature that may be included in a pump incorporating the present invention is an axial spring 86 that may provide a biasing force between the orbiting valve 16 and a fixed structure attached to the housing, such as the end cap 52. The spring is used to overcome the net separating force caused by the difference between (1) the fluid pressure acting on the surface area of the orbit valve 16 contacting the valve plate 25 and (2) the fluid pressure acting on the surface of the orbit valve opposite the orbit valve sealing surface. The spring ensures a seal between the land area surrounding the grooves 22, 24 and the valve plate 25 of the housing 102. Alternatively, one or more axially extending springs may provide a biasing force between orbit valve 16 and eccentric 30. To improve the biasing of the orbit valve, a circumferential projection 16c is provided on the end wall surface of the valve opposite the valve surface having the concentric grooves. The circumferential projection defines a space that receives the end coil of the spring 86. The projection does not of course have to be continuous. Instead of a protrusion, a groove may be provided to receive the end coil of the spring. For convenience, the spring 86 is not shown in its actual relatively coiled and bent state.

Referring to fig. 12a and 12b, an alternative embodiment of an orbit valve having a segment with a grooved section and a straight through section is shown. The associated valve plate 225 has three cylinders, only one cylinder 220a being shown for convenience. The valve plate has three cylinder ports, again for convenience only port 228a is shown containing recessed portion 228a "and through portion 228 a'. The valve plate also has three discharge ports, only one of which 226a is shown for convenience.

The orbit valve 216 shown in fig. 12a and 12b has three intake sections 224a, 224b, 224 c; each section is uniquely associated with one of the three cylinders. In the illustrated embodiment, the entry section 224a is associated with the cylinder 220 a. The intake section penetrates the orbit valve completely. Having the intake section as a through-hole allows direct access to the associated cylinder port, thereby eliminating the need to provide any intake ports in the valve plate.

The orbit valve of fig. 12a and 12b also has three slotted segmented discharge ports; only the discharge port 222a is shown for convenience. Each discharge port segment is uniquely associated with a cylinder and a cylinder port. In the illustrated embodiment, slotted drain section 226a is associated with cylinder port 228a and cylinder 220 a. The discharge section does not penetrate the orbit valve. The orbit valve has a projection similar to the projection 16c shown in figures 5a, 5 b. For convenience, the projection is not shown in fig. 12a, 12 b.

Although the embodiments in fig. 12a and 12b show their entry sections penetrating the orbit valve, they do not have to penetrate the orbit valve. In this case, a suitable inlet port through the valve plate must be provided. Further, in this case, the discharge section may be made as a through hole, so that it is not necessary to have a discharge port in the valve plate. In this case, the cavity in which the orbit valve is enclosed must be pressure sealed. The pressure allowed to build within the cavity is sufficient to overcome the net separation force between the valve plate and the orbit valve, thereby eliminating the need for an external biasing force member such as spring 86. The amount of pressure that can be used as the biasing force should not be so great as to create undue frictional forces between the orbit valve and the valve plate. The pressure may be regulated by a pressure regulation port in the cavity or some other pressure regulator.

The orbit valve 216 must be prevented from rotating relative to the housing by using some possible method, including but not limited to an oldham coupling, one or more idler crank mechanisms, one or more torsion springs, one or more leaf springs, or other compliant mechanisms connected separately between the disk and the stationary housing or formed integrally as a unitary component with the disk itself. For convenience, only four integral flexible compliant arms 216d are shown in perspective view in fig. 12 b.

Springs and protrusions similar to spring 86 and protrusion 16c may also be used to form the resilient compliant member. In this case, the projection for receiving the end coil of the spring may be dimensioned such that the circumferential projection forms a cavity that allows the end coil to be snap-fitted within the cavity. The snap fit serves to couple the spring to the orbit valve with a sufficient friction fit to resist the torsional force exerted by the eccentric on the orbit valve. If a groove is used to receive the spring, a cavity is provided in the groove to receive the spring to limit the orbit valve rotation.

Referring to fig. 12a, 12b, orbit valve 216 may be used with a pump having compression and vacuum cylinders. The cylinder may be a combination of compression and vacuum cylinders. Each cylinder may be associated with a rail valve inlet/outlet pocket, which may be a combination of grooves or through ports. The valve plate and the orbit valve may be configured to interconnect pressure and vacuum cylinders provided within the same pump with appropriate inlet or outlet ports within the valve plate to sequence and provide vacuum and pressure pumping capabilities through separate fluid circuits; or a combination of pumping and motor drive using a pressure or vacuum fluid source and/or a motor in any combination.

Referring to fig. 13, eccentric 30 may include a portion (not shown) that serves as a counterweight to dynamically balance the primary radial power generated by the orbital motion of orbital valve 16. In this case, the balancing moment mass 54 comprises a balancing moment mass to dynamically balance the main drive imbalance moment of the pump or motor and the imbalance moments generated by the orbit valve and its eccentric weights located in two different axial planes.

In another aspect of the invention, orbit valve eccentric 330 can be located on the same side of valve plate 325 as eccentric 64. See fig. 11. In this case, the eccentric 330 is directly coupled to the eccentric 64. The eccentric 64 imparts orbital motion to the eccentric 330 via the eccentric bearing 332. The eccentric 330 transmits orbital motion to the orbit valve 316 through the coupling 300.

While the orbit valve cavities 22, 24 have been described as grooves 22, 24, they may also be channels, passages or conduits. Additionally, although the cavities 22 and 24 are each described as a groove, they may include a combination of grooves and through holes. In this case the port arrangement of the valve plate follows the principles described with reference to fig. 12a, 12 b. The orbit valve can have a variety of shapes other than those shown or described. The valve plate and housing can also have a variety of shapes other than the disclosed shapes.

It should be noted that the term "coupled" is used inclusively herein to include both direct and indirect coupling. For example, the shaft 18 is coupled with the oscillating member 60 through an indirect coupling. The shaft is also coupled to the pistons 14a, 14b by an indirect coupling.

Various embodiments of the present invention have been described in considerable detail. Various modifications and variations to the described embodiments will be apparent to those skilled in the art. Therefore, the present invention is not limited to the embodiments.

The claims (modification according to treaty clause 19)

Translation of a revision statement made in accordance with article 19 of the patent Cooperation treaty

The comparison document Stoyke discloses an orbit valve 18 in a valve chamber 23. On one side of the orbit valve 18 there is an inlet 19 and an outlet 21. On the opposite side of the valve 18 there is a cylinder port. The cylinder port and the discharge or inlet port of claim 1 as amended herein are located on the same side of the orbit valve. Only one side of the orbit valve of the present application rests against a surface having a port therein.

1. A reciprocating pump, compressor, air motor or hydraulic motor having a plurality of cylinders, a plurality of cylinder ports, a plurality of pistons, a rotatable shaft, a housing having at least one outlet and inlet port, a partition having at least one outlet or inlet port and at least one said cylinder port, an eccentric and an orbit valve, wherein said shaft is coupled to said eccentric and said eccentric is coupled to said orbit valve, said orbit valve comprising:

a plurality of cavities;

a first fluid port arrangement location wherein a first pocket of the plurality of pockets is in fluid communication with a first cylinder port of the plurality of cylinder ports, the first pocket also being in fluid communication with the at least one inlet or outlet port within the partition, a second pocket of the plurality of pockets being blocked from fluid communication with the first cylinder port and being blocked from fluid communication with the at least one inlet or outlet port within the partition;

a second fluid port placement location wherein a second pocket of the plurality of pockets is in fluid communication with the first cylinder port, the first pocket being blocked from fluid communication with the first cylinder port, the second pocket being in fluid communication with the exhaust or intake port within the housing; the second cavity being blocked from fluid communication with the at least one outlet or inlet port in the partition; and

wherein during rotation of the shaft, the orbiting valve moves along an orbital path from the first fluid port arrangement position to the second fluid port arrangement position, and the at least one exhaust or intake port is on the same side of the orbiting valve as the at least one cylinder port.

2. The pump, compressor, air motor, or hydraulic motor of claim 1, wherein the orbit valve further comprises a first surface and a second surface oriented opposite the first surface; and

the second cavity extends into the first surface without passing through the second surface.

3. The pump, compressor, air motor or hydraulic motor of claim 1, wherein the orbit valve further comprises:

a first surface and an oppositely oriented second surface; and

the second cavity extends into the first surface and through the second surface to provide a through-hole through the orbit valve.

4. In a reciprocating pump, compressor, air motor or hydraulic motor having a plurality of pistons reciprocating within cylinders disposed about a central axis and a wall having at least one port for each cylinder in communication with a cylinder volume varied by reciprocation of the pistons within the cylinders, the improvement comprising:

an orbiting valve rotatably connected to an eccentric on a central drive shaft so as to orbit substantially about the central axis, the orbiting valve having a cavity on the side of the valve facing the wall, the wall having at least one inlet port between the two cylinders communicating with the cylinder ports through the at least one cavity in the valve, and the wall having at least one outlet port between the two cylinders to provide for the sequential ingress and egress of fluid as the piston travels in time as the orbiting valve orbits against the wall, the cavity passes over the appropriate cylinder port and either the inlet port or the outlet port.

5. The improvement of claim 4, wherein the cavities are annular grooves concentrically disposed with one another and centered about a central axis of the valve, the valve being free to rotate without its angular orientation affecting the interconnection between the cylinder ports and the appropriate inlet and outlet ports.

6. The improvement of claim 4, wherein the cavity is a segment of an arc and has discrete lengths for interconnection between a particular cylinder port and a particular inlet and outlet port, and the disk is prevented from rotating relative to the pump or motor housing by use of a resilient member.

7. The improvement of claim 1, wherein an axial spring biasing force is provided between the orbit valve and the housing.

8. The improvement of claim 4, wherein a sufficient number of cavities and ports are provided to interconnect combinations of pressure and vacuum cylinders provided within the same pump or motor.

9. A reciprocating pump, compressor, air motor or hydraulic motor having a plurality of cylinders, a plurality of cylinder ports, a plurality of pistons, a rotatable shaft, a housing having at least one outlet and inlet port, a partition having at least one outlet or inlet port and at least one said cylinder port, an eccentric and an orbit valve, wherein said shaft is coupled to said eccentric and said eccentric is coupled to said orbit valve, said orbit valve comprising:

a plurality of cavities;

a first fluid port arrangement location wherein a first pocket of the plurality of pockets is in fluid communication with a first cylinder port of the plurality of cylinder ports, the first pocket also being in fluid communication with the at least one inlet or outlet port within the partition, a second pocket of the plurality of pockets being blocked from fluid communication with the first cylinder port and being blocked from fluid communication with the at least one inlet or outlet port within the partition;

a second fluid port placement location wherein a second pocket of the plurality of pockets is in fluid communication with the first cylinder port, the first pocket being blocked from fluid communication with the first cylinder port, the second pocket being in fluid communication with the exhaust or intake port within the housing; the second cavity being blocked from fluid communication with the at least one outlet or inlet port in the partition; and

wherein during rotation of the shaft, the orbit valve moves along an orbital path from the first fluid port arrangement position to the second fluid port arrangement position, the orbit valve having a first surface and an oppositely oriented second surface, and only one of the surfaces bearing against the surface having the port therein.

Claims (8)

1. A reciprocating pump, compressor, air motor, or hydraulic motor having a plurality of cylinders, a plurality of cylinder ports, a plurality of pistons, a rotatable shaft, a housing having at least one outlet port and an inlet port, a partition having at least one outlet port or inlet port, an eccentric, and an orbit valve, wherein the shaft is coupled to the eccentric and the eccentric is coupled to the orbit valve, the orbit valve comprising:

a plurality of cavities;

a first fluid port arrangement location wherein a first pocket of the plurality of pockets is in fluid communication with a first cylinder port of the plurality of cylinder ports, the first pocket also being in fluid communication with the at least one inlet or outlet port within the partition, a second pocket of the plurality of pockets being blocked from fluid communication with the first cylinder port and being blocked from fluid communication with the at least one inlet or outlet port within the partition;

a second fluid port placement location wherein a second pocket of the plurality of pockets is in fluid communication with the first cylinder port, the first pocket being blocked from fluid communication with the first cylinder port, the second pocket being in fluid communication with the exhaust or intake port within the housing; the second cavity being blocked from fluid communication with the at least one outlet or inlet port in the partition; and

wherein during rotation of the shaft, the orbit valve moves along an orbital path from the first fluid port arrangement position to the second fluid port arrangement position.

2. The pump, compressor, air motor, or hydraulic motor of claim 1, wherein the orbit valve further comprises a first surface and a second surface oriented opposite the first surface; and

the second cavity extends into the first surface without passing through the second surface.

3. The pump, compressor, air motor or hydraulic motor of claim 1, wherein the orbit valve further comprises:

a first surface and an oppositely oriented second surface; and

the second cavity extends into the first surface and through the second surface to provide a through-hole through the orbit valve.

4. In a reciprocating pump, compressor, air motor or hydraulic motor having a plurality of pistons reciprocating within cylinders disposed about a central axis and a wall having at least one port communicating with a cylinder volume that is varied by reciprocation of the pistons within the cylinders, the improvement comprising:

an orbiting valve rotatably connected to an eccentric on a central drive shaft so as to orbit substantially about the central axis, the orbiting valve having a cavity on the side of the valve facing the wall, the wall having at least one inlet port between the two cylinders communicating with the cylinder ports through the at least one cavity in the valve, and the wall having at least one outlet port between the two cylinders to provide for the sequential ingress and egress of fluid as the piston travels in time as the orbiting valve orbits against the wall, the cavity passes over the appropriate cylinder port and either the inlet port or the outlet port.

5. The improvement of claim 4, wherein the cavities are annular grooves concentrically disposed with one another and centered about a central axis of the valve, the valve being free to rotate without its angular orientation affecting the interconnection between the cylinder ports and the appropriate inlet and outlet ports.

6. The improvement of claim 4, wherein the cavity is a segment of an arc and has discrete lengths for interconnection between a particular cylinder port and a particular inlet and outlet port, and the disk is prevented from rotating relative to the pump or motor housing by use of a resilient member.

7. The improvement of claim 1, wherein an axial spring biasing force is provided between the orbit valve and the housing.

8. The improvement of claim 4, wherein a sufficient number of cavities and ports are provided to interconnect combinations of pressure and vacuum cylinders provided within the same pump or motor.