Abstract: A rotary positive displacement pump employs the higher pressure available at a region he rotor chamber after the outlet port to augment the force of a biasing spring in a control A biasing spring with a lower spring force can thus be employed in the control system, g in a pump pressure output characteristic which can more closely match the operating varying working fluid requirements for devices supplied by the pump.

Abstract: In a variable displacement pump, a first groove always connected to a second hydraulic chamber is provided in a slide surface of a cam ring facing to an end surface of a side plate, and a second a groove always connected to a suction port is provided in the end surface of the side plate, whereby when the cam ring is moved to a moving end side in which a volumetric capacity of a pump chamber is reduced, the first groove and the second groove are connected, and the second hydraulic chamber can be connected to the suction port by the grooves.

Abstract: Within a cam ring (8), a rotor having a plurality of vanes (27) is eccentrically disposed. A metering orifice (136) is provided halfway on a discharge passage (135) of pressure fluid discharged from the pump, and a control valve is activated due to a pressure difference between the upstream and downstream sides of the metering orifice (136). A fluid pressure of the first fluid pressure chamber (21) is controlled by activation of the control valve (123). The second fluid pressure chamber (22) is shut off from the control valve (123) to introduce a pressure on the suction side at any time. To return the cam ring (8) in a direction of expanding a pump chamber (11), an internal pressure of the cam ring (8) is applied in the return direction.

Abstract: In a hydraulic pump, a cam ring is provided in a cylindrical adaptor for movement in a radial direction, and a differential pressure control valve is provided to control internal pressure and load pressure at the front and back sides of a variable orifice to be introduced into action chambers and formed at the opposite sides of the cam ring for controlling a discharge amount of the pump in accordance with the rotation speed of the pump. The differential pressure control valve is operated under the internal pressure and load pressure respectively introduced into action chambers and the load of a thrust spring biasing the differential pressure control valve toward the internal pressure chamber. The load of the thrust spring is increased or decreased in accordance with an increase or a decrease of the load pressure.

Abstract: In a gear pump with variable throughput volume, with two meshed gears with external toothing which are rotatably held in the working chamber of a pump housing, at least one of the two gears is driven from a drive shaft and one of the gears, preferably the driven gear, is shiftable in the direction of its axis. In order to realize a control mechanism in a simple manner a gap width defined as the distance measured in axial direction between an essentially plane first interior side wall of the working chamber of the pump housing and a first font face of the shiftable gear, is designed to be variable.

Abstract: A lubrication system for an internal combustion engine includes a variable displacement oil pump supported on the engine block and connected to draw oil from the oil pan and to supply pressurized oil to various engine components. The pump defines variable displacement pumping chambers for carrying oil from an inlet to a pressurized outlet. An exemplary embodiment includes a vane pump with a feedback displacement control using pressure from the lubrication system to actuate a slide ring in the pump to control the pump output. Numerous features of the pump are disclosed.

Abstract: A lubrication system for an internal combustion engine includes a variable displacement oil pump supported on the engine block and connected to draw oil from the oil pan and to supply pressurized oil to various engine components. The pump defines variable displacement pumping chambers for carrying oil from an inlet to a pressurized outlet. An exemplary embodiment includes a vane pump with a feedback displacement control using pressure from the lubrication system to actuate a slide ring in the pump to control the pump output. Numerous features of the pump are disclosed.

Abstract: A variable capacity rotary compressor includes a housing defining a cylindrical compression chamber therein and having an inlet port and an outlet port communicating with the compression chamber. A rotating shaft is provided with an eccentric part to rotate in the compression chamber. A ring piston is rotatably fitted over the eccentric part such that an outer surface of the ring piston is in contact with an inner surface of the compression chamber. A vane is installed in the housing so as to be in contact with the outer surface of the ring piston and radially reciprocates, and partitions the compression chamber into an intake part and a discharging part. A re-expansion space communicates with the compression chamber, and receives refrigerant therein. A control unit opens or closes an inlet of the re-expansion space to vary a capacity of the rotary compressor.

Abstract: A variable capacity rotary compressor includes a housing having a cylindrical compressing chamber defined therein, a rotating shaft having an eccentric body part which rotates in the compressing chamber, a ring piston fitted over the eccentric body part of the rotating shaft so as to have the ring piston rotate while being in contact with an inner surface of the compressing chamber, a vane mounted in the housing so as to have the vane advance or retract in a radial direction of the compressing chamber in accordance with a rotation of the ring piston, and a control unit which is connected to the vane and moves in opposite directions in response to pressures of a refrigerant inlet and a refrigerant outlet of the compressor, so as to control a moving range of the vane. Accordingly, a simpler construction of the compressor is achieved and a refrigerant compressing capacity is easily controlled.

Abstract: A variable capacity pump includes a housing and a rotatable rotor within the housing. The rotor includes radial slots to accommodate slidable vanes or rotor blades, wherein the vanes are urged outwards by centrifugal force into contact with the inner surface of a surrounding cam ring. The cam ring is surrounded on one end by a pressure chamber including a piston under hydraulic pressure, and on the other end by a seated spring. By controlling the pressure distributed to the pressure chamber, the position of the cam ring with respect to the rotor may be changed to automatically vary the displacement of the pump in response to a pressure differential across a restriction orifice, thereby regulating the output flow to be constant over a defined speed range.

Abstract: In a variable displacement pump, a pressurizing cylinder is provided in an opposite side of the first fluid pressure chamber, holding the cam ring there between, and a piston inserted to the pressurizing cylinder collides with the cam ring. A pressure in an upstream side of both throttle passages comprising the variable throttle passage and the fixed throttle passage provided in the pump discharge side passage is introduced to the first fluid pressure chamber and the oil chamber of the pressurizing cylinder, and a pressure in a downstream side of the both throttle passages is introduced to the second fluid pressure chamber.

Abstract: A variable capacity pump includes a housing and a rotatable rotor within the housing. The rotor includes radial slots to accommodate slidable vanes or rotor blades, wherein the vanes are urged outwards by centrifugal force into contact with the inner surface of a surrounding cam ring. The cam ring is surrounded on one end by a pressure chamber including a piston under hydraulic pressure, and on the other end by a seated spring. By controlling the pressure distributed to the pressure chamber, the position of the cam ring with respect to the rotor may be changed to automatically vary the displacement of the pump in response to a pressure differential across a restriction orifice, thereby regulating the output flow to be constant over a defined speed range.

Abstract: A regulatable pump, in particular a vane pump, is provided with a rotor, with a rotor body and with at least one guide ring and with a cam ring. The eccentricity of the cam ring can be adjusted by means of a regulating piston, a journal of the cam ring lying between a spring-pretensioning means and the regulating piston. At maximum eccentricity, the cam ring bears on the outside by means of a bearing part of its circumferential wall against a bearing surface on the inside of the housing.

Abstract: The present invention relates to a system that provides independently operated or controlled circuits in a single device. An exemplary application adapts a variable displacement roller pump into an engine geometry control system that uses one circuit of the pump during start-up and then removes the circuit from the system and satisfies other pumping needs with the other circuit of the pump.

Abstract: A regulatable pump, in particular a vane pump, is provided with a rotor, with a rotor body and with at least one guide ring and with a cam ring. The eccentricity of the cam ring can be adjusted by means of a regulating piston, a journal of the cam ring lying between a spring-pretensioning means and the regulating piston. At maximum eccentricity, the cam ring bears on the outside by means of a bearing part of its circumferential wall against a bearing surface on the inside of the housing.

Abstract: A variable pump or motor is providing including a housing with inlet and outlet ports and a vaned rotor. Spool ends are provided at either end of the rotor thereby enhancing the effective sealing of the pump and its overall efficiency. Piston actuators are also described. A sealing means is provided in conjunction with the use of a flexible belt wherein volumetric efficiency is substantially improved.

Abstract: A variable displacement pump includes pump bodies, a cam ring, first and second fluid pressure chambers, a rotor, a driving shaft, a pump chamber, a compression coil spring, a metering restrictor portion, and a control valve. A plunger damper is formed to incorporate the compression coil spring such that a distal end of the plunger damper abuts against a side portion of the cam ring in the second fluid pressure chamber. A small hole constituting the metering restrictor portion is formed at such a position that it is opened/closed by a slidable motion of the plunger damper during a swing motion of the cam ring, and such that it is partitioned from the second fluid pressure chamber, so that an opening area of the small hole changes in an interlocking manner to the swing motion of the cam ring.

Abstract: A variable capacity pump includes a rotor, a plurality of vanes, a cam ring, a spring, a variable orifice, first and second fluid pressure chambers, and first and second openings. The spring biases the cam ring to a position where a volume of the pump chamber of a portion ranging from a pump suction region to a pump discharge region becomes maximum. The variable metering orifice is formed midway along a discharge passage of a pressure fluid discharged from the pump chamber. The first and second fluid pressure chambers are formed between the outer circumferential portion of the cam ring and the inner circumferential surface of the pump body to be divided in a biasing direction of the cam ring, and swing the cam ring upon introduction of input and output fluid pressures of the metering orifice thereto. The first and second openings respectively open to the pump suction region and the pump discharge region of the pump chamber to have opening areas that are changed by a swing of the cam ring.

Abstract: In a controllable vane pump for pumping lubricant through a lubricant circulating system of an internal combustion engine wherein a pivotally supported control ring surrounds the vanes which rotate with the pump rotor and engage the inner walls of the control ring to form therewith pump spaces for pumping an amount of fluid which depends on the pivot position of the control ring and means are provided for biasing the control ring with a certain force toward a pivot position for greatest pump volume, the control ring defines with the housing an inlet pressure chamber which is maintained at the pressure of the lubricant at the pump inlet and a discharge pressure chamber which is maintained at the pump discharge pressure whereby the differential force generated by the pressures in said inlet and discharge pressure chambers is balanced by the force applied to the control ring by the control ring biasing means.

Abstract: Multi-stage regulator for lubricant pumps with continuously adjustable displaced volumes in particular for lubricant pumps, with a regulating piston to which pressure can be applied from pressure derived from the output side of the pump, and with increasing pressure can be displaced counter to the force of a flexible restoring element.

Abstract: An first rotor and an second rotor rotate about a longitudinal axis in a housing. The second rotor moves longitudinally relative to the first rotor. Rotor vanes extend outward from the rotors and are longitudinally split into longitudinally extending second vanes and longitudinally extending first vanes that slide longitudinally relative to one another. The second vanes travel longitudinally with the second rotor relative to the first rotor, and the second vanes slide relative to the first vanes that remain with the first rotor. The second rotor and the second vanes move longitudinally toward and away from a recess defined by the first rotor such that the active surface area of the rotor vanes is varied. When the second vanes slide away from the first vanes, surfaces of the first vanes are exposed that reciprocate into and out of specially defined chambers in a pump-like fashion. A movable element is connected to and extends from the second rotor.

Abstract: To restrain the swinging of a movable displaceable cam ring and a spool of a control valve and to suppress pulsation on the discharge side of a variable displacement pump. In the variable displacement pump, a variable metering orifice (40) is provided midway in discharge-side passages (24, 29, 43, 44, 45) extending from a pump chamber. A spool-type control valve (30) is operated with the fluid pressure on the upstream and downstream sides of the orifice to control the fluid pressure supplied to fluid-pressure chambers around the cam ring in accordance with the flow rate of the fluid discharged from the pump chamber. A single or multistage throttle portion including throttles (50, 51, 52) is provided in at least one of fluid passages (46, 47) for communicating the upstream side of the orifice to one chamber of the valve, and fluid passages (35, 19b) for communicating the one chamber to the first fluid-pressure chamber as the valve operates.

Abstract: A durable, single action, variable displacement vane pump capable of undervane pumping, components thereof, and pressure balancing method. The pump comprises a cylindrical barstock rotor member having large diameter journal ends and central vane slots uniformly spaced therearound. The vane slots are elongate and have a central vane-supporting portion of maximum depth surrounded at each end by extension portions having depths which decrease axially to the surface of rotor member. The vaned rotor is rotatably supported within a unitary cam member having opposed faces and a circular bore therethrough forming a cam chamber having a continuous interior circular cam surface. The vane slot extensions in the rotor project outwardly beyond the cam chamber.

Abstract: A variable capacity or displacement type pump by which a pump discharge quantity is variably controlled in accordance with the revolution number, which has simple construction to contributes easier machining and assembling, and is reliable in operation. A cam ring is movably arranged to define a pump chamber around a rotatable rotor within a pump body and is biased so that the volume of the pump chamber is made maximum. Sealing members are provided in an annular space between the cam ring and the pump body so as to define first and second hydraulic pressure chambers through which the cam ring is driven to move. A switch valve is provided to control the hydraulic pressure transmitted to the first and second chambers in accordance with the quantity of the flow discharged from the pump chamber.

Abstract: A cam ring for forming a pump chamber on the outer periphery of a rotor which is rotatable in a body is arranged movably, and is urged in a direction in which the volume of the pump chamber is made maximum. Sealing means are interposed in an annular gap space on the outer periphery of the cam ring between the cam ring and the body, thereby forming first and second fluid-pressure chambers for allowing the cam ring to undergo displacement by moving. A spool-type changeover valve is provided which is operated in accordance with the discharge flow rate of the pressure fluid from the pump chamber to control the fluid pressure supplied to the first and second fluid-pressure chambers. The fluid pressure on the downstream side of a metering orifice 29 provided in a pump discharge-side passage 28 is introduced into the second fluid-pressure chamber for imparting moving displacement in the direction in which the volume of the pump chamber is made maximum, through a passage 37 via a second valve chamber 32b.

Abstract: A vane pump has a casing, a controlling collar guided leaktightly in the casing and movable relative to a rotor mounted in the casing and surrounded by the controlling collar. The movement of the collar is transverse to the axial direction of the rotor. A suction region of the pump is defined by a volume increasing in the direction of rotation of the rotor, of a vane cell formed between two adjacent vanes and decreasing to the pressure region. At least one adjustment member is provided to adjust the position of the controlling collar in dependence on the prevailing pumping parameters. In order to provide a vane pump of space-saving and/or simple and cost-saving design, at least one recess is open towards the outside of the controlling collar and is provided on the controlling collar close to the pressure region to accommodate and adjustment member.

Abstract: Methods and devices for enhancing bootstrap hydraulic systems for use in vehicular power steering systems are disclosed. Improved pressure dividing networks are provided for enabling balanced operation of supply pressure control function when valve input shaft and sleeve are in relative centered positions or for enabling a first method of providing speed sensitive control of steering assist. Control valves utilizing a combination of open-center and closed-center flow control orifices are provided for reducing parasitic pressure losses. An improved variable displacement pump is provided for enabling volumetric flow rate efficient operation of bootstrap systems. A vehicular speed dependent command signal for a servo motor powered bootstrap hydraulic system is utilized in another method of providing speed sensitive control of steering assist.

Abstract: A noise and cavitation suppressing variable fluid volume vane type rotary pump has fluid inlet and outlet ports in communication with the interior portion of a pump housing. A cam ring is arranged in an inner chamber of the pump housing, for enabling adjustment of fluid flow volume in the pump, and the cam ring is pivotable for allowing eccentric displacement thereof. A rotor having a plurality of vanes arranged in the radial direction thereof so as to make touching contact with an inner circumferential surface of the cam ring is rotatably arranged in the space defined within the inner circumference of the cam ring. First and second containments are defined at uppermost and lowermost points between the cam ring and the rotor. The cross sectional areas of the containments vary according to eccentric displacement of the cam ring.

Abstract: A lubricating groove not communicating with other oil passages and extending in the circumferential direction is provided on the side surface of a cam ring. The central portion in the circumferential direction of the lubricating groove is located at the center of the suction side, and both ends of the lubricating groove reach the positions beyond a straight line joinning the upper and lower dead points. As a result, the side surface of the cam ring of the variable-displacement vane pump is prevented from seizing.

Abstract: A vane pump or a vane motor is here specified, having a variable displacement volume. The vane pump has a vane rotor and an annular stator that surrounds the rotor eccentrically and that is stabilized by means of a piston arrangement for adjusting the eccentricity that determines the displacement volume. The piston arrangement includes at least one pendulum piston that is acted upon by a pressure medium, the pendulum piston being guided in a sealed manner in a housing bore by a piston head that delimits a control space. To simplify the assembly and to decrease manufacturing costs while simultaneously improving the sealing action and increasing the peripheral life of the guide surfaces, plastic rings, which are composed of wear resistant, sliding material, or are prestressed radially, to guide the piston in the piston bore and to seal the control space are embedded, inserted or emplaced in the piston head.

Abstract: A variable volume type vane pump comprises a housing, a rotor having a plurality of vanes, a cam ring disposed to be adjacent to said rotor, and a cover. A control piston is arranged for slidably displacing the cam ring relative to the housing and the cover. The housing, the cam ring, the control piston, and the cover cooperating to define an oil reservoir. A pressure within the oil reservoir is adjusted by a check valve.

Abstract: A variable capacity type vane pump comprising a cam ring, a rotor placed for rotation within the cam ring. The rotor has a number of radial slots, and vances placed for radial inward and outward movement in the receptive slots each having a bottom. A pump chamber is defined between the cam ring and the rotor and it has an inlet and outlet port. The outlet port is connected through a conduit to the bottom of at least one of the slots having vanes moving inwardly in the respective slots. A restriction orifice is placed in the conduit. The cam ring is moved with respect to the rotor to vary the capacity of the vane pump in response to a pressure differential across the restriction orifice.

Abstract: A variable-displacement vane-pump has a rotor which is rotatably supported by a pump housing in coaxial relationship therewith, and a cam ring interposed between the rotor and the pump housing in eccentric relationship with the pump housing. The rotor has radially outwardly slidable vanes on its outer peripheral surface in contact with an inner surface of the cam ring. Two side plates are disposed on both sides of the vanes, thereby defining pump chambers between every adjacent vanes. An arc-shaped intake port and an arc-shaped exhaust port are formed in one of two side plates, and respectively open into the pump chambers along one side face of the cam ring. In the other side face of the cam ring, a groove is formed except for the region corresponding to the exhaust port, and a partially cut off annular friction ring is disposed within the groove while urged by a seal ring into close contact with the other side plate.

Abstract: A hydraulic circuit comprising a control pump having first and second adjustment means for changing the output volume of fluid pump, and a regulating valve adapted to suppy user means with a pressurized liquid.

Abstract: The invention relates to a radial piston machine comprising height adjustment means, control means and adjustment means all having abutment means designed such that the cam ring of the machine will carry out during its adjustment a substantially rolling movement.

Abstract: In general terms the invention provides for a direct actuated pressure regulated vane-type pump having a adjustment piston which is under the influence of the pump pressure. The adjustment piston is coupled to said cam ring by means of a flexible or articulate connection means, or else the adjustment piston itself is of a flexible or articulate design.

Abstract: A variable vane-type pump in which a cam ring with variable eccentricity encompasses a rotary piston comprising vanes guided in radial slots. At least one lateral surface of the rotary piston abuts on the contact surface of a control disc with pressure pocket and suction pocket. A channel is provided in the control disc whose intake opening is disposed in the direction of rotation of the pump between pressure pocket and suction pocket and in direct vicinity of the end of the pressure pocket. The channel terminates in a housing chamber, the waste oil chamber, the lubricating channels and/or into the under-vane chambers. After displacement of the cam ring, a connection can be established between the channel and the pressure pocket so that the pressure fluid still delivered can discharge via the channel to safeguard lubrication of the pump.

Abstract: A vane type variable displacement motor comprising a body having an elliptical first bore, end caps with axial bores, an axial drive shaft journaled therethrough and a rotor on the shaft. A plurality of radial vanes are movably mounted upon and around the rotor and are biased toward the first bore and react to pressurized liquid delivered through intake and exhaust passages in the body. Rotative pistons upon the shaft within the end cap bores have a series of radial slots to receive the vanes whereby the pistons are adapted for axial movement relative to the vanes into the first bore for modifying the effective internal volume of the first bore and speed of shaft rotation. Pilot ports in the end caps are connected to a variable pressure source for biasing the pistons variably into the first bore.

Abstract: A gear pump in which one rotating, toothed pump gear is supported axially displaceable in the pump casing and engaging an axially displaceable sliding part at least on the one face wall of the pump gear. The sliding part is adapted to overlap the operating space or zone of engagement of the displaceable pump gear against the other, axially stationary pump gear, with hydraulic relief provided by the pump casing and/or the sliding part by pocket-like recesses on the side diametrically opposing the pressure side of the pump across the displaceable pump gear, the recesses hydraulically communicating with the pressure side of the pump.

Abstract: A control valve for a variable displacement pump is improved so that the levelling of the pressure fluctuations of the pump is better and quicker. For this purpose an additional control piston portion on the control piston of the control valve is used. Corresponding to the deflection of the control piston the constriction cross-section set by the control piston portion between the supply connected to the pump pressure line and a passage leading to the control space of the variable pump is varied so that the pressure rise in the control space of the pump and also the pressure drop is accelerated.

Abstract: A hydraulically driven bicycle frame with two axle members coupled to the bicycle frame and front and rear wheels mounted on such axles for rotation about the axis of the respective axle and a pair of pedals mounted on a pedal drive shaft coupled to the bicycle frame for rotation for applying manual power for operating the hydraulic system of the bicycle. The hydraulically driven bicycle has a hydraulic pump mechanism and a hydraulic drive mechanism. The hydraulic pump mechanism is operated by rotational movement of the pedal drive shaft. The hydraulic pump mechanism includes a pump housing having two sectional pump housing members that form a pump chamber between them. The two sectional pump housing members are capable of relative movement with respect to each other so that the pump chamber is capable of being varied in size for varying the flow of fluid through the pump mechanism.

Abstract: A variable-capacity roller- or vane-type pump has a cam ring which is movable to vary the delivery of the pump and means is provided for applying to the movement of the cam ring a damping force which varies in dependence upon the instantaneous position of the cam ring.

Abstract: An adjusting arrangement for a vane or radial piston pump in which the forces applied outwardly to the cam ring are compensated by the application of hydraulic pressure to each of a plurality of sections about the ring. System pressure is applied to one section and a regulating pressure to another. A spring or hydraulic arrangement absorb any force differential.

Abstract: A control valve for a variable displacement pump is improved so that the levelling of the pressure fluctuations of the pump is better and quicker. For this purpose an additional control piston portion on the control piston of the control valve is used. Corresponding to the deflection of the control piston the constriction cross-section set by the control piston portion between the supply connected to the pump pressure line and a passage leading to the control space of the variable pump is varied so that the pressure rise in the control space of the pump and also the pressure drop is accelerated.

Abstract: A roller or vane type pump is described of the kind in which the cam ring is pivotally mounted within an external casing to vary the throw of the cam ring and hence the pump delivery means is provided whereby a constant flow is obtained regardless of the pump speed. The cam surface of the cam ring is not wholly circular. The two portions of the cam surface extending between the inlet and outlet ports of the pump at opposite sides respectively of the pump axis have curvatures such that the instantaneous distance R.sub.2 of the point of contact of one of the sealing rollers or vanes with the cam surface from the axis of rotation of the rotor is given by R.sub.2 =.sqroot.R.sub.1.sup.2 +k where k is a constant and R.sub.1 is a corresponding instantaneous distance of the point of contact of the other sealing roller or vane with the cam surface from said axis.

Abstract: In a vane pump having a casing, an annular rotor rotatably disposed in the casing, a plurality of vanes longitudinally movably carried by the rotor, and a cam ring eccentrically disposed about the rotor with its cylindrical inner surface slidably contacting with the leading ends of the vanes, the cam ring having at the diametrically opposed portions thereof inlet and outlet ports which face in the same direction, there is proposed a measure in which a groove is formed in the cam ring near the inlet port and faces in the same direction as the inlet and outlet ports, and in which the groove is connected to the outlet port for balancing the cam ring.

Abstract: A sliding vane type rotary pump having two sets of radially slidable vanes and two rotors, each vane set cooperating with a rotor to form a separate pump section with plural chambers. Each pump section is longitudinally spaced one from the other on a pump shaft's axis interiorly of a common housing. A common pump outlet and a common pump inlet are positioned between the two pump sections to provide fluid inflow and fluid outflow. The inflow to and outflow from each pump section's vane/rotor defined chambers is generally parallel to the pump shaft's longitudinal axis, and is through the side face of the pump section defined by each set of chambers.

Abstract: A pump has a stator formed with intake and output ports connected to the lubricating system of an internal-combustion engine of an automotive vehicle for flow therethrough, a rotor in the stator positively driven by the engine output, an adjustment element operatively connected to the stator and rotor and displaceable between one end position corresponding to relatively great flow through the pump when the rotor is rotated by the output and an opposite end position corresponding to substantially no flow through the pump when the rotor is rotated by the engine output, and a biasing unit for urging the adjustment element toward the one end position with a fixed force. An abutment unit is connected to the adjustment element of the pump for limiting displacement of same from an intermediate position between its end positions into the opposite end position corresponding to no flow through the pump.

Abstract: A variable output vane pump for use with an automotive automatic transmission. At least one pressure chamber is formed between the circular bore of a housing and the outer circumference of a ring by means of at least one seal pin which is fitted in the axial groove formed in the ring circumference and which is opened in the housing bore. The ring is urged by the action of a spring, which is fitted in the housing, in a direction opposite to the pressure to be built up by the pressure chamber. An elastic member is fitted in the bottom of the axial groove to urge the seal pin both toward the housing bore and at the same time toward one of the side walls of the axial groove. The urging direction of the elastic member and a tangential line, on which the seal pin is tangential to the housing bore, are angularly positioned at an acute angle with respect to each other.

Abstract: There is provided a control device for a vane type variable displacement pump. The control device eliminates the need of a hydraulic cylinder to control the eccentricity of a cam ring of the vane pump. A pressure difference between a second chamber and a high pressure side of the pump first chamber on a low-pressure side of the vane pump is utilized to determine the eccentricity of the cam ring. A regulator valve is connected to the first chamber and with the second chamber in order to allow or prevent communication between the two chambers. A spring is also provided to always force the cam ring in a direction so as to make the eccentricity of the cam ring larger.