Abstract: A reversible gerotor pump system is provided. The gerotor pump system includes a cylindrical housing with a 180° slot, an eccentric ring with a locking pin fixed thereto and movably engaged in the slot; an outer rotor and inner rotor with meshed teeth, and shaft for driving inner rotor and system. The eccentric ring has a convex profile on the outer diameter. A positive contact system, which can be a spring-and-plunger system or frictional disc brake system is provided to increase frictional force between the eccentric ring and the outer rotor. The locking pin moves in the slot with clearance at both rotation directions to provide a self-damping effect. The suction port has prolongations at both upstream and the downstream sides to increase filling time such that the pump can have a fill speed of above 5000 rpm, and the volumetric efficiency is at least 90% at 5000 rpm.

Abstract: The disclosure relates to a pump assembly for a vehicle having an internal combustion engine with or without transmission or electric motor with transmission or for an oil supply having a double-pipe pump, wherein the two pipes are separated from each other and a second pipe can be connected to a first pipe, wherein the pump has at least one input drive point for an electric machine and also for a drive motor, including, for example, via a gearbox.

Abstract: An electrohydraulic actuator assembly for use in a brake-by-wire hydraulic brake system. The electrohydraulic actuator assembly includes a pair of electrohydraulic actuator EHA units. One EHA unit provides fluid to front brakes and the other EHA unit provides fluid to rear brakes. Each EHA unit includes an electric motor, a reduction gear unit, a pair of magnetorheological clutches, and a pair of fluid pumps. The system further including an ECU that actuates the electric motor and controls engagement of the clutches to cause the fluid pump to pump brake fluid to at least one of the front and rear brakes. The system further includes a regeneration system for providing supplemental electricity to the electric motors.

Abstract: A lubricating oil supply apparatus may include a rotational portion that rotates together with a rotational shaft and a fixed portion that maintains a fixed location thereof and supplies oil through a space that circles with respect to a rotational center of the rotational portion, thereby supplying oil regardless of a rotational direction of the rotational shaft.

Abstract: A transfer case for a motor vehicle, comprising a housing, an input shaft, a first output shaft, which is arranged substantially coaxially with the input shaft and is operatively drive-connected to the input shaft, a second output shaft, which is arranged offset in relation to the input shaft and which is or can be operatively drive-connected to the input shaft via an offset mechanism, in the form of a flexible traction drive, and via a clutch unit, an actuator unit which serves for actuating the clutch unit, the actuator unit comprising a ramp mechanism having a first ramp disk fixed to the housing and a second, axially displaceable ramp disk, and a carrier shaft which is embodied as a hollow shaft and which at least partially encloses the input shaft, the carrier shaft being rotatably supported on the first ramp disk via a radial bearing.

Abstract: A transfer device of a vehicle is provided, which includes an input shaft for receiving an output torque of a drive source at an axial first side, a main-wheel output part provided on a second side and for outputting the output torque to main drive wheels, an auxiliary-wheel output shaft provided in parallel to the input shaft and for outputting the output torque to auxiliary drive wheels, a coupling provided on the input shaft and for extracting a part of the output torque, a drive member having a hollow section and provided on the input shaft, a driven member provided on the auxiliary-wheel output shaft and meshed with the drive member, a universal joint provided on the auxiliary-wheel output shaft, and a damper device provided on the input shaft or the auxiliary-wheel output shaft and for reducing noise that occurs due to a variation of the output torque.

Abstract: A vehicle transfer case has a first input drive means, a first output drive means and a second output drive means. A first epicyclic gear set is provided in the transfer case. The first epicyclic gear set includes a first sun gear, a plurality of first planetary gears, a first planet carrier and a first ring gear. A first clutch means is configured to control the first epicyclic gear set. The first output drive means is drivingly coupled to the first input drive means; and the first clutch means selectively drivingly couples the second output drive means to the first input drive means.

Abstract: A lubricating device for a gear train (5) including a plurality of gears meshing with each other includes a shroud (7) configured to cover the gear train (5) and a housing (9) configured to cover the shroud (7). The shroud (7) includes: an oil supply nozzle (25) configured to supply oil (OL) to a meshing position (21) of the gear train (5); and oil-drain ports (41) through which the oil (OL) is discharged from the shroud. The housing (9) includes, at its lower part, a draw-out port (43) through which the oil (OL) discharged from the oil-drain ports (41) is drawn to the outside of the housing. Guide members (47) are provided between the shroud (7) and the housing (9). The guide members (47) guide the oil (OL) discharged from the respective oil-drain ports (41) of the shroud (7) such that the oil (OL) flows downward through space (S) between the shroud (7) and the housing (9).

Abstract: A oil pump includes a pump housing in which a first partitioning section is formed between a trailing end section of the intake port and a leading end section of the discharge port, and a second partitioning section is formed between a trailing end section of a discharge port and a leading end section of an intake port. A width dimension of the second partitioning section is the same as or larger than the formation range of a space between teeth which is constituted by an inner rotor and an outer rotor passing the second partitioning section during low-speed rotation. A protruding surface section is formed in the same plane as and continuously with the second partitioning section from the vicinity of an inner diameter side of the trailing end section of the discharge port.

Abstract: A reversible gerotor pump for a machine having a drive shaft is provided, the pump including a housing, an offset ring, and an inner and outer gear. The offset ring is disposed in the housing and includes a tab extending radially from an outer periphery. The outer periphery of the offset ring defines a first axis in common with the axis of a drive shaft. The inner periphery of the offset ring defines a second axis that is slightly offset from the second axis. The axis of the outer gear moves relative to the axis of the inner gear to allow pumping action in both rotational directions using the same suction and line cavities for both directions.

Abstract: A pump having an actuator mounted on a rotatable shaft, and a pump mounted on the shaft, which is selectively engageable with the actuator. When the actuator is actuated, the pump will receive rotational force from the shaft, creating a pumping. action.

Abstract: The fluid system is intended for an oscillating-piston engine (100) which has at least two double-armed oscillating pistons (4) arranged in a spherical housing (19) and revolving together about an axis (23) of revolution arranged in the housing center, wherein the oscillating pistons, when revolving, mutually perform reciprocating oscillating movements about an oscillation axis (24) perpendicular to the axis (23) of revolution, and guide members (5) attached to at least two pistons (4) engage in at least one guide groove (17) formed in the housing (19) and serving to control the oscillating movements. The fluid system (70) comprises at least one central feed opening (1), lying in the vicinity of an end of the axis (23) of revolution, for a fluid, continuous cavities and/or bores (10) in the pistons (4) for the fluid, and a fluid discharge on the outer side (3) of the respective piston.

Abstract: A reversible gerotor pump for a machine having a drive shaft is provided, the pump including a housing, an offset ring, and an inner and outer gear. The offset ring is disposed in the housing and includes a tab extending radially from an outer periphery. The outer periphery of the offset ring defines a first axis in common with the axis of a drive shaft. The inner periphery of the offset ring defines a second axis that is slightly offset from the second axis. The axis of the outer gear moves relative to the axis of the inner gear to allow pumping action in both rotational directions using the same suction and line cavities for both directions.

Abstract: A rotary compressor has two compression capacities according to two different rotational directions of the driving shaft. The rotary compressor includes a driving shaft with an eccentric portion. A roller rotates on the shaft along an inner circumference of the cylinder. A vane installed in the cylinder continuously contacts the roller. An upper and a lower bearing are respectively disposed on the top and bottom of the cylinder. A disc shaped valve rotates between two positions and has at least one suction port for selectively supplying refrigerant inside the compression chamber according to the rotational direction of the driving shaft and at least one discharge port communicates with the compression chamber for discharging the compressed refrigerant. The refrigerant is supplied through a communication hole to a port formed on the outer valve.

Abstract: A single stage root type vacuum pump has a pair of outside air introduction holes formed in the vicinity of a phantom line in an inner wall surface within a range between intersecting points, where the intermediate position that is located between the center of a driving side rotor shaft and the center of a driven side rotor shaft of three-lobe rotors intersects with the intersecting points at which internal circles located on the extended circumferences of the inner wall surface of the casing. The pair of outside air introduction holes formed in symmetrical positions into horizontally long slit shapes parallel to a width direction of the casing. Check valves are fitted to tip end portions of outside air introduction pipes which are respectively connected to outside air communication holes for preventing air from escaping at the time of reverse rotation of the three-lobe rotors.

Abstract: A rotary compressor includes a driving shaft having an eccentric portion, a cylinder, and a roller installed on an outer circumference of the eccentric portion to contact an inner circumference of the cylinder, performing a rolling motion along the inner circumference and forming a fluid chamber to suck and compress fluid along with the inner circumference. A vane is installed elastically in the cylinder to contact the roller continuously. Discharge ports communicate with the fluid chamber. Suction ports communicate with the fluid chamber and are spaced apart from each other by a predetermined angle. A valve assembly selectively opens any one of the suction ports according to a rotation direction of the driving shaft. Compression spaces having different volumes are formed in the fluid chamber according to the rotation direction of the driving shaft such that two different compression capacities are formed.

Abstract: A rotary compressor includes a driving shaft rotatable clockwise and counterclockwise, and an eccentric portion of a predetermined size; a cylinder forming a predetermined inner volume; a roller installed rotatably on an outer circumference of the eccentric portion to contact an inner circumference of the cylinder; a vane installed elastically in the cylinder to contact the roller continuously; a first bearing installed in the cylinder, for supporting the driving shaft rotatably; a second bearing rotatably supporting the driving shaft and preliminarily storing the fluid to be sucked; discharge ports communicating with the fluid chamber; and a valve assembly having openings separated by predetermined angle from each other, wherein compression spaces that have different volumes from each other are formed in the fluid chamber according to the rotation direction of the driving shaft so that two different compression capacities are formed.

Abstract: A rotary compressor for changing a compression capacity of the compressor includes a driving shaft being rotatable clockwise and counterclockwise, and having an eccentric portion of a predetermined size; a cylinder forming a predetermined inner volume; a roller installed rotatably on an outer circumference of the eccentric portion so as to contact an inner circumference of the cylinder; a vane installed elastically in the cylinder to contact the roller continuously; a first bearing installed in the cylinder, for rotatably supporting the driving shaft; a second bearing installed in the cylinder, for rotatably supporting the driving shaft and guiding the fluid into the fluid chamber; discharge ports communicating with the fluid chamber; and a valve assembly having openings separated by a predetermined angle from each other, the valve assembly having a center which is eccentrically installed by a predetermined distance from a center of the cylinder.

Abstract: A rotary compressor having two different compression capacities is provided. The rotary compressor may include a driving shaft that is rotatable in both a clockwise and counterclockwise direction, and having an eccentric portion at an end thereof. The compressor may also include cylinder having a predetermined inner volume, and a roller rotatably installed on an outer circumferential portion of the eccentric portion so as to contact an inner circumference of the cylinder and form a fluid chamber therebetween. A vane is elastically installed in the cylinder and contacts the roller, and upper and lower bearings are respectively installed at upper and lower portions of the cylinder so as to rotatably support the driving shaft and hermetically seal the inner volume of the cylinder. Suction and discharge ports communicate with the fluid chamber based on a rotational direction of the driving shaft so as to provide a different compression capacity depending on the rotational direction of the driving shaft.

Abstract: A rotary compressor that has two compression capacities is provided. The rotary compressor includes a driving shaft having an eccentric portion and being rotatable in both clockwise and counterclockwise directions, a cylinder having a predetermined inner volume, and a roller rotatably installed on an outer circumferential surface of the eccentric portion so as to contact an inner circumferential surface of the cylinder. The roller performs a rolling motion along the inner circumferential surface of the cylinder and forms a fluid chamber therewith. A vane is elastically installed in the cylinder, contacting the roller, and upper and lower bearings are respectively installed at upper and lower portions of the cylinder to rotatably support the driving shaft and hermetically seal the inner volume of the cylinder. A compression mechanism forms different sizes of compressive spaces in the fluid chamber based on a rotational direction of the driving shaft.

Abstract: In an oil pump employing a cam ring, and inner and outer rotors in meshed-engagement, two housings are provided at opposite ends of the cam ring. A plurality of volume chambers are defined between inner and outer teeth of the rotors. Two axial holes are formed in the cam ring. A first one of the axial holes is positioned corresponding to a mesh portion having a minimum volume, whereas the second axial hole is positioned corresponding to a trap portion having a maximum volume. A suction port and a discharge port are formed at least in one of the housings and are open to the volume chambers between the mesh and trap portions. All are positioned at a line symmetry of an axis line between the mesh and trap portions. At least one of the two axial holes is formed as a slot extending along the axis lines.

Abstract: A device for handling and recovering of kinetic energy in a fluid is presented which basically features a bladed impeller (11). The impeller is operated by an electric engine (12) and acts as a centrifugal blower yielding energy to the air when the main engine is in a low boost phase; otherwise in case of excessive boost pressure, the impeller receives the moving fluid which will drive its rotation, reducing pressure and absorbing the energy to operate the electric engine (12) which will act as a reversible electric machine, thus generating electric power.

Abstract: An oil pump is provided which includes a cam ring made of a material having a first line expansion coefficient, a pump element rotatably disposed in the cam ring and smaller in an axial length than the cam ring, a first housing member disposed on one of axially opposite sides of the cam ring and made of a material having a second line expansion coefficient larger than the first line expansion coefficient, and a second housing member disposed on the other of the axially opposite sides of the cam ring and made of a material having a third line expansion coefficient than the first line expansion coefficient.

Abstract: A control system for a variable displacement pump. The control system is operably associated with an engine control unit for passively or actively controlling the output of the pump in response to signals from the engine control unit.

Abstract: An inter-axle differential assembly having a lubrication pump is provided. The pump is disposed between the input and output shafts of the differential within a bore defined by a side gear coupled to or integral with the output shaft. The pump includes a housing that defines first and second ports and includes an arcuate groove in a radially outer surface. A pin extends radially inwardly from the side gear and is received within the groove. The groove and pin cooperate to enable rotation of the entire pump relative to the side gear and to thereby exchange the positions of the two ports. In this manner, the assembly provides a reversible pump that provides lubricant only during relative rotation between the input and output shafts of the differential.

Abstract: A compressor assembly including a compression mechanism, a rotating crankshaft operably coupled to the compression mechanism, the crankshaft provided with a longitudinally-extending oil conveyance passageway, the oil conveyance passageway in fluid communication with relatively moving interfacing bearing surfaces of the compression mechanism, and an oil pump assembly. The oil pump assembly includes an oil pump body having an interior surface and being rotatable relative to the crankshaft, a vane disposed within the pump body and rotating with the crankshaft, the vane having at least one end in sliding engagement with the interior surface of the oil pump body, and a port plate disposed within the pump body and having rotatably opposite first and second positions. The vane is in sliding engagement with an adjacent surface of the port plate, and the port plate is provided with an inlet and an outlet.

Abstract: A reversible gerotor-type pump having an angularly moveable reversing ring rotatably supporting an internally toothed rotor which in turn cooperates with an externally toothed gear received within the rotor and rotatable therewith about an axis parallel to but spaced from the axis of rotation of the rotor, and, magnet means magnetically attracting the rotor towards the reversing ring so as to provide drag between the rotor and the reversing ring at least at the commencement of rotation of the rotor relative to the reversing ring.

Abstract: A bi-directional fluid pump for providing a source of pressurized fluid. The fluid pump includes a gerotor assembly, an inlet valve system, and an outlet valve system which work cooperatively to provide pressurized fluid during two directions of rotation.

Abstract: Hydraulic passages for an oil pump for a speed reducer used in electric vehicle include a first passage for connecting an inlet port of an oil pump to an oil reservoir through a first check valve, a second passage for connecting an outlet port of the oil pump to a discharged-oil demand part through a second check valve, a third passage for connecting the outlet port to the oil reservoir through a third check valve, and a fourth passage for connecting the inlet port to the discharged-oil demand part through a fourth check valve. The check valves are disposed such that, upon normal rotation of the oil pump, the first and second check valves are opened, and upon reverse rotation thereof, the third and fourth check valves are opened.

Abstract: A hydrostatic transmission for a transaxle which contains two flanged mounting surfaces which are used to secure the transmission to the lower housing of the gear axle. A third point is used as a pilot diameter during assembly but is not required to secure the transmission to the gear axle. Such an arrangement provides a compact and efficient hydrostatic transmission for a transaxle which can be readily assembled and also provides extended service life for the internal components of the hydrostatic transmission.

Abstract: A hydromechanical system for limiting differentiation between a first rotating member and a second rotating member in a drivetrain subassembly. The hydromechanical system comprises a clutch assembly for selectively coupling the first rotating member to rotate with the second rotating member and a hydraulically actuated piston assembly for applying force on the clutch assembly to actuate the clutch assembly in response to hydraulic pressure such that the first rotatable member is selectively coupled to rotate with the second rotatable member. A clutch actuating pump, including a reservoir, is provided for supplying hydraulic pressure to the piston assembly to actuate the piston assembly, wherein the clutch actuating pump communicates hydraulic fluid under pressure to the piston assembly in response to differential rotation between the first and second rotating members.

Abstract: The invention provides a hydromechanical system for limiting differential speed between first and second rotating members of a vehicle drivetrain subassembly. The hydromechanical system comprises a casing disposed within a housing of the subassembly which is rotatably coupled to the first rotating member of the drivetrain subassembly. Hydraulic fluid is supplied from a sump within the drivetrain subassembly housing to a reversible hydraulic pump disposed within the casing, wherein the reversible hydraulic pump pumps hydraulic fluid in response to relative rotation between the first and second rotating members. A piston assembly is disposed within the casing which includes a guide member, an actuating member and a chamber disposed therebetween, wherein the chamber receives the pumped hydraulic fluid.

Abstract: An eccentric pump with lock valve and with bidirectional rotational operation, mainly for lubricant circulation of drives comprises a stationary outer casing having two parallel side walls and a cylindrical inner surface between the side walls, and further having inlet and outlet openings being sealingly separated and terminating in the cylindrical inner surface, a middle shaft arranged within the casing concentrically to the cylindrical inner surface and having a cylindrical surface being eccentric to the middle shaft as well as to the cylindrical inner surface of the casing, a circular sealing ring being sealingly displaceable in respect of the eccentric surface of the shaft as well as to inner wall portions of the casing, and further having a radial slot sealingly engaging a stationary pin with its both limiting surfaces.

Abstract: A reliable scroll-type compressor is provided which, even when the compressor is rotated in the reverse direction by the erroneous connection of the power source terminals for example, is prevented from establishing a vacuum state within the compression chamber and no damages occur in the addendum of the stationary scroll and the orbiting scroll. The compressor includes a gear pump which includes a pump case and a pump port. The arrangement of the present invention is such that the pump case alone rotates by 180 degrees upon the reverse rotation of the motor, so that lubricating oil which is at the bottom of a hermetic vessel can be ensured to be supplied by the gear pump to each sliding portion of the compressor.

Abstract: Lubricant is pumped into a lubrication system by an oil pump. Preferably the lubricant is drawn into the pump from an unagitated source. An eccentric pump rotor is received on the crankshaft and has a circumferentially extending recess. A radially extending drive pin is secured in the crankshaft and coacts with the ends of the recess to position the rotor in accordance with the direction of rotation of the shaft.

Abstract: A gear pump including a body, a port plate, a pair of gerotor-type rotors, one rotor being connected to a shaft, and a retaining assembly operative on the port plate to rotatably couple it to the body. The retaining assembly permits adjustment of axially oriented inlet and outlet ports disposed in the port plate to vary fluid flow from the pump. Both manually and automatically adjustable retaining assemblies are disclosed.

Abstract: A rotor rides on the shaft end and is eccentric with respect to the rotational axis of the shaft. The rotor rotates in the bore of a pivot ring and coacts therewith in the nature of a double action pumping such that there are two pumping cycles per revolution of the shaft.

Abstract: A gerotor pump comprises the usual lobed annulus 30 containing the lobed rotor (not shown in FIG. 2) which is journalled on cylindrical boss 36. The boss is free to turn on the eccentric pin 38 between positions controlled by limit pin 42 encountering end abutments. This enables the pump to automatically adjust to the variable direction of drive of the annulus--in this case via coupling 32--so as to be unidirectional in fluid output via flow passages 16 18.

Abstract: A reversible unidirectional flow gerotor pump (FIG. 1) has an externally cylindrical internally lobed rotor (36) internally meshed with an eccentrically located externally lobed male rotor having a smaller number of lobes (40) and the annulus runs in a cylindrical cavity in carrier ring 22 pivoted on pin 20 via slot 24. The carrier ring is located in a cylindrical cavity in the body of the pump and is free to translate along the line 18, with accompanied movement along the line 44, this movement occurring automatically when the direction of rotation of the driven rotor 40 is reversed, and resulting in continued pumping flow in the same direction through the pump.

Abstract: A reversible gear-type pump providing constant fluid delivery direction on alternating drive direction in which an eccentric ring receiving the outer rotor is pivotal through 180.degree. between two end positions by frictional engagement with the outer rotor wherein the eccentric ring is made contractible as a whole to establish the coupling engagement with the outer rotor and expandable to disengage the coupling engagement. The eccentric ring can be made in one piece from resilient material or can be formed from a plurality of arcuate segments which are pressed together by an annular spring engaging around them.

Abstract: A gerotor pump is arranged for unidirectional flow irrespective of direction of rotation of the pump by arranging for displacement of the axis of eccentricity of the annulus and rotor upon drive reversal, the annulus being mounted in a carrier 14, FIG. 1, with freedom for movement in a first direction within the carrier, while the carrier itself is pivoted (24) in an outer housing 15, the carrier being free for movement in a second direction within the housing. The effect of normal drive of the rotor is to hold the parts in the FIG. 1 position while pumping continues, but in the event of drive reversal a pressure fluctuation causes the annulus to be displaced within the carrier and then the carrier to be displaced within the housing so as to bring the parts to substantially the mirror image of the FIG. 1 position allowing continued pumping in the same direction from inlet to outlet under reversed drive.

Abstract: A reversible flow vane pump having a pump case with a pump chamber in which a rotor is mounted. The rotor has outwardly-opening slots which carry vanes which engage a cam ring and with fluid chambers between vanes. The cam ring can be adjusted to positions at either side of a neutral position to provide reversible flow operation between a pair of ports, with variable volume control. The ports are arranged to increase the length of time in which a port communicates with an intervane fluid chamber which is of decreasing volume for increased utilization of fluid being pressurized. A port which functions as an inlet port in a predominant mode of operation of the pump has an extension effective to increase the length of time in which an intervane fluid chamber of increasing volume can be filled with fluid.

Abstract: A gerotor pump of n and n+1 type has the annulus and rotor located in a chamber with one wall provided by a floating coverplate held in place by a spring so that in the event of excess internal pressure the cover can lift to allow cross leakage between the inlet and outlet sides of the pump. FIG. 2 illustrates a typical embodiment.

Abstract: A bi-directional internal/external gear pump with advanced porting includes inlet and outlet ports symmetrical about a line perpendicular to the port centerline. An internal/external gear set is rotatable on parallel axes establishing the hydraulic centerline, which is advanced relative to the port centerline by some predetermined angle. One axis may be revolved about the other to shift the hydraulic centerline by substantially 180.degree. minus twice the angle of advance.

Abstract: The pump drive shaft may rotate in either direction. The pump discharges liquid from the same port, regardless of the direction of rotation. A receiving port on the pump mounting pad is aligned with that discharge port. The pump includes a base plate, a pump plate and a cover plate, aligned with a stack. The pump has a single inlet diametrically opposite the point where the gears mesh. This inlet acts in either direction of rotation so that no valves are needed in the inlet passage. Two outlet ports are located respectively on opposite sides of the mesh point. All fluid passages and a valve means which selects one outlet port or the other, depending on the direction of rotation, are located in the base plate. All valves are simple structures trapped in chambers between the base plate and the pump plate, or between the base plate and the mounting pad. The inlet is made narrower than the teeth on the gears to prevent cavitation.

Abstract: A reversible positive displacement rotary fluid pump comprising a rotor with either dual sliding vanes or a single vane defining pumping cavities of increasing and decreasing volume and having a single non-valved inlet for both directions of rotation, outlet flow being controlled by a valve plate rotatable to one of two positions, as determined by the direction of rotation of the pump.

Abstract: A reversible positive displacement rotary fluid pump comprising a rotor with dual sliding vanes defining pumping cavities of increasing and decreasing volume and having a single non-valved inlet for both directions of rotation, outlet flow being controlled by a valve plate rotatable to one of two positions, as determined by the direction of rotation of the pump, and a stationary porting plate.

Abstract: The pump drive shaft may rotate in either direction. The pump discharges liquid from the same port, regardless of the direction of rotation. A port on the pump mounting pad, which receives the discharge from the pump, may be in any of various locations. The pump has plural discharge ports at different locations on its base plate, one of which is aligned with the receiving port on the mounting pad. Any discharge port not used in any particular embodiment is blocked. The pump includes a base plate, a pump plate and a cover plate, aligned in a stack. In one modification, all fluid passages and a valve means which controls the direction of the flow are located in the base plate. In other modifications, a valve plate is provided, and the valve means is located in the valve plate. The fluid passages may be completely in the valve plate or partly in some of the other plates. All valves are simple structures trapped in chambers between or within the plates.

Abstract: A reversible gerotor pump having unidirectional fluid flow therefrom dictated by a movable eccentric ring member 30 for positioning the rotor 46 of the pump gear-set 44 in either one of two axially eccentric positions depending upon the direction of rotation of the drive shaft 20 to the pump. Movement of the eccentric ring member from one such position to the other position upon a reversal of direction of the drive shaft is caused by check valve means 70 associated with the pump inlet 68 so that, if reverse rotation of the drive shaft momentarily causes reverse flow of the pumped fluid (e.g., causes the fluid to exit through the inlet) the check valve closes and establishes a hydraulic lock between the gear-set and forces the eccentric ring member to move from the one position to the other eccentric position whereupon the fluid is once again caused to be discharged through the normal pump outlet 64 and enter through the inlet.

Abstract: A gear pump for unidirectionally transporting a fluid such as oil has a stationary housing with an inlet port and an outlet port on opposite sides of the axis of a cylindrical chamber in which a ring with an eccentric inner periphery is rotatable through an arc of 180.degree. between two limiting positions. Freely rotatable within the inner ring periphery is an annular outer rotor with internal gear teeth entrainable by a driven inner rotor with external gear teeth, the latter numbering one less than the internal gear teeth of the outer rotor. A face of the ring has one or more shallow depressions open toward the outer rotor, each depression being spanned by a leaf spring which is anchored to the ring and defines with the outer periphery of that rotor a wedge-shaped gap diverging symmetrically toward its ends to form alternate lodgments for a rotary coupling member such as a ball or a roller.