Abstract: A variable hydraulic pump include a rotor mounted on a pump housing of which a housing spring end is formed, a pivot pin, an outer ring rotatably coupled to the pivot pin and of which a ring spring end is formed, a spring mounted between the housing spring end and the ring spring end, a pressure chamber formed in the pump housing to push the outer ring, a plurality of vane provided to form a plurality of pockets, an input port to supply oil to the plurality of pockets and a discharge port to exhaust oil supplied to the plurality of pockets, wherein at the reference position of the outer ring, the angle between a first imaginary line connecting the center of the rotor and the pivot pin and a second imaginary line connecting the ring spring end and the pivot pin is 0 to 10 degrees.

Abstract: In a variable displacement oil pump, a drain chamber 36 partitioned with respect to first and second control oil chambers 31, 32 and which serves to generate a biasing force in a concentric direction based on a pump drain pressure directly introduced from a drain port 22a is interposed between first control oil chamber 31 which serves to generate a biasing force in the concentric direction in which a volume variation quantity of a plurality of pump chambers PR for a cam ring 15 based on a control pressure as a main gallery pressure introduced from an internal combustion engine and second control oil chamber 32 which serves to generate the biasing force in an eccentric direction in which the volume variation quantity of the plurality of pump chambers PR is increased for cam ring 15 based on the control pressure.

Abstract: A variable displacement oil pump is described. The oil pump has a pump body connected to an intake channel and to a delivery channel, a rotor capable of rotating inside the pump body about a rotation axis and provided with a plurality of vanes. The oil pump has an oscillating stator arranged in an eccentric position around the rotor and pivoted inside the pump body at a rotation pin. The oil pump has adjustment means for adjusting the displacement of the oil pump which acts on the oscillating stator to displace it with respect to the rotor and position it in at least one predetermined operative position. The adjustment means has first thrusting means configured to exert a first thrusting action on a first outer surface portion of the oscillating stator arranged on a substantially opposite side with respect to the rotation pin taking as a reference the rotor.

Abstract: HVAC systems and methods for delivering highly efficient heating and cooling using ambient air as the working fluid. A plenum has an upstream inlet and a downstream outlet, each in fluid communication with a target space to be heated or cooled. Ambient air is drawn into the inlet at an incoming pressure and an incoming temperature. The inlet and outlet are gated, respectively, by first and second rotary pumps. A heat exchanger in the plenum transfers heat into or out of the air, provoking a change in air volume within the plenum. Work is harvested in response to change in air volume. The systems and methods can be configured to replace a traditional blower fan used to circulate the interior and exterior air. The systems and methods can be configured to implement a technique referred to as Convergent Refrigeration.

Abstract: It is intended to provide a vacuum pump so that without upsizing the vacuum pump, noise and vibration are reduced, heat dissipation property is secured, and the casing is downsized. Therefore, at least one turning part is provided in an exhausting path formed in a casing body. The casing body is formed of a material whose thermal conductivity is higher than that of a rotor and vanes, and a cylinder part where the vanes slide is press fitted in the casing body.

Abstract: An adjustable rotary vane pump configured to reduce pressure pulsations during hydraulic fluid discharge includes a housing having two side plates positioned in parallel. Each side plate has multiple grooves formed in its surface. A rotor mounted between the side plates has multiple vanes extending radially outward. A lift ring surrounds the rotor, pivotally connected to the housing to swivel between positions eccentric to the housing. During rotation of the rotors, the vanes divide the annular region between the rotor and the lift ring into multiple cells, which alternately position themselves between a suction zone and a pressure zone of the pump. In a transition region between the suction and pressure zone, when the lift ring is between pre-determined angular positions, the grooves within lift ring and the side plate substantially align to create an overflow channel, which transfers the hydraulic fluid from the suction zone to the pressure zone.

Abstract: A variable displacement lubricant pump for providing a pressurized lubricant for an internal combustion engine includes a shiftable control ring. The control ring comprises a plurality of pump chambers and a pressure relief valve. The plurality of pump chambers rotate through a charge zone and a discharge zone. A pump rotor comprises radially slidable vanes. The pump rotor rotates in the control ring. A pretensioning element pushes the control ring to a high pumping volume direction. A first control chamber pushes the control ring to a low pumping volume direction. A second control chamber pushes the control ring to the high pumping volume direction. A pump outlet is connected to the first control chamber. A throttle valve connects the first control chamber with the second control chamber. The pressure relief valve of the control ring connects the discharge zone to the second control chamber.

Abstract: A variable displacement pump includes: a discharge opening formed at a position to confront a discharge region; a back pressure introduction groove formed on the suction region side; and a discharge side thin wall portion which is formed in the second housing, which has a recessed shape opened to the outside, which is disposed on the discharge region side, which is overlapped with the rotor in the radial direction, and which includes a smallest thickness portion having a smallest wall thickness of thicknesses each of which is an axial length between a bottom surface of the recessed shape and an axially inner side surface of the second housing, the smallest wall thickness being a smallest wall thickness of axial thicknesses of the second housing.

Abstract: The invention relates to a vane cell pump, having a rotor mounted in a pump housing and driven by a shaft, multiple vane plates mounted in this rotor in radially displaceable manner, and an outer ring surrounding the rotor and the vane plates, whereby this ring is disposed either directly in the pump housing or in a setting ring that can be moved in the pump housing along predetermined paths.

Abstract: A lubricant pump system may include a lubricant pump controlled by a proportional valve. An actuating unit may be disposed in the lubricant pump and configured to control a delivery output of the lubricant pump. A first pressure chamber and at least one second pressure chamber may be configured to adjust the actuating unit against a spring, wherein the second pressure chamber is smaller than the first pressure chamber. In response to a failure of the proportional valve, the lubricant pump may be exclusively pressurized via the at least one second pressure chamber.

Abstract: An oil pump for a vehicle including a sealing apparatus is provided for preventing leakage of oil from the regulator chamber. The oil pump includes a sealing chamber formed between the outer ring and the housing, a sealing apparatus disposed in the sealing chamber, and an oil passage formed in the outer ring to facilitate a fluid communication of the sealing chamber with the regulator chamber. The sealing apparatus includes a contact portion, first and second sealing members. The first sealing member closely contacts the contact portion if the second sealing member is pushed by the hydraulic pressure of the regulator chamber supplied thereto through the oil passage, and thus prevents leakage of oil from the regulator chamber.

Abstract: Vane pump mechanical losses are reduced by removing vane friction losses and replacing them with lower magnitude journal bearing fluid film viscous drag losses. A freely rotating cam ring is supported by a journal bearing. A relatively low sliding velocity is imposed between the cam ring and the vanes). This permits the use of less expensive and less brittle materials in the pump by allowing the pump to operate at much higher speeds without concern for exceeding vane tip velocity limits.

Abstract: A rotary pump with an improved seal on a control pressure chamber, including: a housing having a delivery chamber; a feed wheel rotatable in the delivery chamber; an actuating member surrounding the feed wheel forming delivery cells and moveable in the housing relative to the feed wheel. The control pressure chamber is delineated by the actuating member together with axially facing axial co-operating surfaces, forming an axial sealing gap and a radial sealing gap. A control fluid can be introduced into the control pressure chamber for applying pressure to the actuating member to exert an actuating force in the actuating direction; a restoring device for generating a restoring force; and a sealing element arranged on the actuating member or the circumferential co-operating surface. To compensate for a change in gap width of one of the axial sealing gaps, a base leakage cross-section is provided on the sealing element.

Abstract: A vane cell pump has a rotor mounted in a pump housing and driven by a shaft, multiple vane plates mounted in the outer circumference of this rotor, and an outer ring that surrounds the rotor and the vane plates, whereby this ring is disposed either directly in the pump housing, or in a setting ring that can be moved in the pump housing, along predetermined paths. The vane cell pump has transverse grooves disposed in the cylinder mantle surface of the rotor, between the bearing grooves of the vane plates, running over the entire rotor width, disposed parallel to the bearing grooves of the vane plates, spaced apart from the bearing grooves by a bearing crosspiece. These transverse grooves have a non-symmetrical cross-section progression, which has a low point in each cell chamber, which point is always disposed behind the cell chamber center axis, seen in the direction of rotation.

Abstract: Vane pump mechanical losses are reduced by removing vane friction losses and replacing them with lower magnitude journal bearing fluid film viscous drag losses. A freely rotating cam ring is supported by a journal bearing. A relatively low sliding velocity is imposed between the cam ring and the vanes. This permits the use of less expensive and less brittle materials in the pump by allowing the pump to operate at much higher speeds without concern for exceeding vane tip velocity limits.

Abstract: An adjustable vane cell pump is provided having a rotor, which includes, but is not limited to bearing slots extending in radial direction, in which cane plates displaceable relative to the bearing slots are arranged. The vane cell pump further includes, but is not limited to an adjustable slide having a substantially cylindrical inner surface. The rotor is configured in order to driveably rotate about a rotary axis within the slide. The vane plates bear against the inner surface of the slide, and the slide further includes, but is not limited to a first and a second areal end face, as well as recesses, which outer-circumferentially extend parallel to the end faces.

Abstract: A variable displacement pump including a control mechanism shiftable between first and second states, when the control mechanism is in the first state, the spool is in an initial position in which fluid communication between an introduction port and the remaining ports is restrained, fluid communication between a first control port and a drain port is allowed, and fluid communication between a second control port and the drain port is restrained, and when the control mechanism is shifted to the second state in accordance with increase in fluid pressure discharged, the spool is in an operating position in which the fluid communication between the introduction port and the first control port is allowed, the fluid communication between the first control port and the drain port is restrained, and the fluid communication between the second control port and the drain port is allowed.

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 vane pump includes a vane cam mounted in a recess of a rotor, and configured to move with eccentricity with respect to an axis of rotation of the rotor. A cam port is formed in a surface of a pump body facing the vane cam, and configured to hydraulically communicate with the recess of the rotor. The vane cam includes an outer peripheral surface configured to contact a proximal end of each of vanes, and configured to cause projection of the vanes along with rotation of the rotor. The vane cam hydraulically separates the proximal end portion of a first slot in a suction region from the proximal end portion of a second slot in a discharge region.

Abstract: An oil pump includes a capacity adjustment mechanism that changes the pump capacity by moving a tubular body in a tube radial direction, with a pump chamber formed between the tubular body and an outer circumference side of a rotor, a first spring biasing the tubular body in a direction in which pump capacity increases, a control valve that converts oil pressure of the oil pump into control pressure and causes the control pressure to act on the capacity adjustment mechanism, and a second spring biasing a valve body in order to set the control pressure in the control valve. The relationship of the biasing forces of the first and second springs is set so that pump capacity is set to maximum when the engine rotational speed is less than a predetermined value, and so that pump capacity is reduced when the engine rotational speed exceeds a predetermined value.

Abstract: A variable displacement vane pump includes: a plate side high pressure introduction groove formed in the pressure plate or in the cam ring, formed so that an entire is positioned within a radial width of the cam ring, and a part is positioned in a circumferential region between the suction port and the discharge port, and arranged to receive a hydraulic pressure larger than a suction pressure; and a housing side high pressure introduction groove formed in the second housing or in the cam ring, formed so that an entire is positioned within the radial width of the cam ring, that a radial center is positioned radially outside the radial center of the plate side high pressure introduction groove, and that a part is overlapped with the plate side high pressure introduction groove in the circumferential direction, and arranged to receive the hydraulic pressure larger than the suction pressure.

Abstract: A variable capacity vane includes a pump control ring which is moveable to alter the capacity of the pump and the pump can be operated at either of at least two selected equilibrium pressures. The pump ring is moved by at least first and second control chambers, the control chambers abutting the control ring such that pressurized fluid supplied to them acts on the pump control ring to move the pump control ring to reduce the volumetric capacity of the pump. When pressurized fluid is supplied to only one control chamber, the pump operates at a first equilibrium pressure and when pressurized fluid is also supplied to the second chamber, the pump operates at a second equilibrium pressure. Pressurized fluid can also be supplied only to the second control chamber to operate the pump at a third equilibrium pressure and/or additional control chambers can be provided if required.

Abstract: An enclosed compressor includes a compression element configured to compress a working fluid, a casing and a fixing member. The casing has a substantially cylindrical shell plate and houses the compression element. The fixing member is welded to the shell plate. The compression element is fixed to the fixing member by at least six fastening bolts.

Abstract: A lubrication system for a power transmission device includes a variable displacement vane pump including a moveable control ring for varying the displacement of the pump. A linear actuator directly acts on the control ring for moving the control ring between maximum and minimum pump displacement positions. The linear actuator includes an electric motor for rotating a drive member. The drive member engages a driven actuator shaft to cause linear translation of the actuator shaft in response to rotation of the drive member. A control system includes a controller for signaling the actuator to extend or retract the actuator shaft to vary the pump displacement.

Abstract: A variable capacity vane pump has a plurality of vanes radially extendably installed in their respective slots that are arranged in a circumferential direction in a rotor, a cam ring rockably provided on a supporting surface in a pump body and forming a plurality of pump chambers at an inner circumference side of the cam ring in cooperation with the rotor and the vanes, and a seal member provided at an outer circumference side of the cam ring and defining a first hydraulic pressure chamber located at a side where a pump discharge amount increases and a second hydraulic pressure chamber located at a side where the pump discharge amount decreases in a space outside the outer circumference of the cam ring. A center of the cam ring is offset to an inlet port side from a center of a driving shaft.

Abstract: In a variable capacity vane pump, a space between adjacent vanes is 1 pitch. A line that connects a half-pitch-advanced position from an end edge of an inlet port or from an end edge of an outlet port and a driving shaft center in a no-load state is termed a port reference line. A line that connects a center of a cam ring inner circumference side and the driving shaft center when an eccentricity amount of a cam ring is a maximum is termed a high pressure cam profile reference line. A line that connects the center of the cam ring inner circumference side and the driving shaft center at a low pressure when the eccentricity amount of the cam ring is a minimum is termed a low pressure cam profile reference line. The three reference lines; the port reference line, the high pressure cam profile reference line and the low pressure cam profile reference line, is set to be substantially parallel to each other.

Abstract: A variable displacement pump including a drive shaft, a cam ring eccentrically moveable with respect to an axis of the drive shaft, and a solenoid drivingly controlled on the basis of variation in electric current amount to be supplied to the solenoid which is controlled in accordance with an operating condition of a vehicle. The solenoid is configured such that a rate of change in the specific discharge amount relative to the electric current amount to be supplied to the solenoid under a condition that the specific discharge amount is smaller is reduced as compared to a rate of change in the specific discharge amount relative to the electric current amount to be supplied to the solenoid under a condition that the specific discharge amount is larger.

Abstract: The invention relates to a vane pump (1), in particular a regulatable oil pump for a lubricating system, with a pump housing (2) with at least one housing tank (6) and with a vane rotor (11) disposed in the housing tank (6) mounted so that it can be rotated by means of a drive shaft (10) in the pump housing (2) constituting an axis of rotation (23) which provides a mount for vanes (15) in approximately radially extending fitting slots (14). An adjusting ring (27) is provided enclosing the vane rotor (11) and circumferentially bounding pump cells (26) which, by means of a cylindrical internal wall surface (31), can be displaced between a concentric position with respect to the vane rotor (11) and an eccentric position relative thereto, to which pressured is applied by positioning torques caused by the medium pressure and a positioning mechanism (47) in order to regulate a pressure level.

Abstract: Variable displacement oil pump includes a: rotor; vanes; cam ring; housing; biasing member biasing the cam ring in a direction enlarging an eccentricity between centers of the rotor and inner circumferential surface of the cam ring; a contact surface to contact with a cam ring outer circumferential surface via a biasing force applied to the cam ring by the biasing member; a control chamber separately formed by the contact surface and a swing fulcrum of the cam ring on a cam ring outer circumference when the contact surface contacts the cam ring outer circumferential surface, and causing the cam ring to swing against the biasing force of the biasing member by a pressure from a discharge portion to the control chamber; and a choking portion formed on the outer circumferential surface of the cam ring to maintain a pressure of the control chamber even when the cam ring swings.

Abstract: The present invention is a variable displacement pump system for delivering precisely controlled oil flow and pressure, including a variable displacement pump having an inlet passage, an outlet passage, a first chamber and a second chamber for controlling the displacement of the variable displacement pump. The present invention also includes a fluid control device for receiving fluid from the outlet passage, and selectively delivering fluid to the second chamber. Fluid is delivered from the inlet passage to the outlet passage from the variable displacement pump, and fluid is also delivered from the outlet passage to the first chamber and the fluid control device. When fluid pressure is greater in the first chamber relative to the second chamber, the displacement of the variable displacement pump will decrease, and when fluid pressure is greater in the second chamber relative to the first chamber, the displacement of the variable displacement pump will increase.

Abstract: An adjustable rotary vane pump configured to reduce pressure pulsations during hydraulic fluid discharge includes a housing having two side plates positioned in parallel. Each side plate has multiple grooves formed in its surface. A rotor mounted between the side plates has multiple vanes extending radially outward. A lift ring surrounds the rotor, pivotally connected to the housing to swivel between positions eccentric to the housing. During rotation of the rotors, the vanes divide the annular region between the rotor and the lift ring into multiple cells, which alternately position themselves between a suction zone and a pressure zone of the pump. In a transition region between the suction and pressure zone, when the lift ring is between pre-determined angular positions, the grooves within lift ring and the side plate substantially align to create an overflow channel, which transfers the hydraulic fluid from the suction zone to the pressure zone.

Abstract: A variable displacement vane pump having various construction arrangements, including a low pressure supply passage constantly connecting an inlet passage and an other of a first fluid pressure chamber and second fluid pressure chamber; a low pressure introduction port formed in the other of the pump body and the rear body, and opened in an other of the first fluid pressure chamber and the second fluid pressure chamber; and a low pressure introduction passage formed in the other of the pump body and the rear body, the low pressure introduction passage connecting the low pressure introduction port and the inlet ports.

Abstract: An impeller for a vane cell pump includes, but is not limited to vane receptacles for receiving an at least radially movable pump vane. A chamber wall is formed between two adjacent vane receptacles to form a conveying chamber. The chamber wall has an axially projecting web for delimiting a movement of a position ring with respect to the radial movement of the pump vane. The chamber wall includes, but is not limited to a first wall region for secure receiving of the respective pump vane in the vane receptacle. The chamber wall further includes, but is not limited to a second wall region for forming a web thickness d of the web for secure abutment of a sintering tool. In addition, the chamber wall has a third wall region for forming an enlarged conveying chamber volume. As a result, the impeller is easily manufactured and has an enlarged pump capacity for the same installation space.

Abstract: A variable displacement vane pump includes a first and a second fluid pressure chamber (31,32) where the cam ring (4) is made eccentric to the rotor (2) by a pressure difference between the first and the second fluid pressure chamber (31,32), a control valve (21) for controlling a pressure of the first and the second fluid pressure chamber (31,32) so that an eccentric amount of the cam ring (4) is reduced to be small with an increase in a rotation speed of the rotor (2), a pressure applying section (36) for applying a pressure to the cam ring (4) in a direction of increasing the eccentric amount all the time, and a cam ring movement restricting portion (12) for defining a minimum eccentric amount of the cam ring (4) by restricting the movement of the cam ring (4) in a direction of decreasing the eccentric amount.

Abstract: A pump including a pressure plate having two inlets and outlets, wherein each inlet has an auxiliary intake port in fluid communication with the inlet, and each outlet has an auxiliary discharge port in fluid communication with the outlet, and a cam/rotor assembly attached to the pressure plate. The cam/rotor assembly includes a rotatable cam having an opening, a rotor within the cam opening, the rotor having multiple radial slots, and multiple vanes that move within the slots, wherein a pumping chamber is defined by a space between rotor and cam. Rotor rotation within the cam causes the vanes to extend and retract within the pumping chamber. The movement of the vanes discharges into the outlets and auxiliary discharge ports a fluid drawn into the pumping chamber via inlets and auxiliary intake ports. The auxiliary inlet and auxiliary discharge ports reduce pressure pulsations in a variable displacement dual-lobe vane pump.

Abstract: A variable capacity vane pump (100) has a pump housing (10) having a high-load bearing part (10a) on which a higher load is exerted than another part when the pump vane pump (100) operates. A control valve (21) for varying a capacity of the vane pump (100) is provided in a valve housing (28) which is formed integrally in the pump housing (10). By arranging the valve housing (28) on the same side of the pump housing (10) as the high-load bearing part (10a) with respect to the rotation axis of the vane pump (100), the high-load bearing part (10a) can be reinforced without increasing the size of the vane pump (100).

Abstract: A variable displacement pump including a rotor, a plurality of vanes, a swingable cam ring, a suction port and a discharge port, wherein a dynamic radius of the vane which extends from a center of the rotor to a leading edge of the vane is gradually decreased in a closed section that is defined between a terminal end of the suction port and an initial end of the discharge port, along with rotation of the rotor, and a port timing defined as a position of the terminal end of the suction port or a position of the initial end of the discharge port with respect to a rotational position of the vane varies along with a swing motion of the cam ring.

Abstract: A vane type vacuum pump 1 is provided in the vicinity of an air intake passage 11 for sucking the air into a pump chamber 2, and communicates a space A on the front side and a space B on the back side of the rotational direction of the vane at the time of the reverse rotation of the vane 6, and includes an escaping groove 21 for allowing a lubricating oil to escape into the space B on the back side from the space A on the front side.

Abstract: A variable displacement pump includes: a pump body; a rotor; a cam ring; inlet and outlet ports; first and second fluid pressure chambers; a metering orifice provided in a discharge passage connected with the outlet port; a pressure regulating section arranged to regulate the pressure introduced into the first or second fluid pressure chamber, and including a high pressure chamber, a middle pressure chamber, and a low pressure chamber; a relief valve; a pilot orifice provided in a passage connecting the metering orifice and the middle pressure chamber, and having a circular section with a diameter of a mm; and a damper orifice provided in a passage connecting the outlet port and the high pressure chamber, and having a circular section with a diameter of b mm. The pilot orifice and the damper orifice satisfy the following relationships: a+2b?2.1?0, ?4a+b?16.3?0, and a?1.8.

Abstract: A variable displacement vane pump includes a rotor, a swingable annular cam ring receiving therein the rotor, a pump body encasing the cam ring and rotor, and a pressure plate which is disposed between an end wall of the pump body and the rotor and which includes a backup surface and a sliding surface formed with an inlet port, an outlet port and a backpressure groove. The vane pump further includes a seal member which is provided between the backup surface of the pressure plate and the end wall of the pump body, and which includes an inlet-side segment extending on the radial inner side of the inlet port and the radial outer side of the backpressure groove, and an outlet-side segment extending on the radial outer side of the outlet port.

Abstract: A pump unit includes a main pump (4) and a charge pump (5), the pump capacity of which is adjustable via an adjusting element. To adjust the pump capacity of the charge pump (5), an adjusting element of the charge pump (5) is acted upon by an adjusting force which is dependent on the inlet pressure of the main pump (4).

Abstract: The disclosure relates to a vane cell pump having an external rotor, an internal rotor and a plurality of vanes which are secured in a pivotable manner on the external rotor and which are displacably mounted in a radial manner in the inner rotor, essentially in radial slots. The external rotor is guided along the inner circumferential surface of a stator. The axis of the stator and the axis of the internal rotor are offset in relation to each other, and the stator can be adjusted in the radial direction in relation to the internal rotor and can be modified by the offset. Said stator is partially enclosed by a clamp which is mounted in a pivotable bearing in the housing of the vane cell pump. The clamp includes clamp arms which protrude on both sides of the pivotable bearing, which partially enclose, respectively, the stator.

Abstract: A pump apparatus includes a drive shaft supported rotatably in a pump body; a power transmission member attached to the drive shaft, and configured to transmit power to the drive shaft; a pump element configured to pressurize and discharge working fluid; a discharge passage formed in the pump body, and configured to introduce the pressurized working fluid-discharged from the pump element to an external of the pump body; a control valve configured to control an amount of working fluid to be discharged through the discharge passage to the external, by controlling a movement of a valving element of the control valve on the basis of the pressurized working fluid; and an electromagnetic valve provided between the power transmission member and the control valve, and configured to control the control valve or a fluid pressure acting on the valving element of the control valve based on the pressurized working fluid.

Abstract: A variable displacement pump includes: a pump section arranged to be driven by an internal combustion engine, and to discharge a lubricant introduced from an induction portion to a plurality of hydraulic chambers, through a discharge portion, by volume variations of the hydraulic chambers; a variable mechanism arranged to move a movable member by using the discharge pressure of the lubricant, and to vary volumes of the hydraulic chambers which are opened to the discharge portion; and an urging section arranged to urge the movable member in a direction to increase quantities of the volume variations of the hydraulic chambers, the urging section having a spring constant which increases as a movement distance of the movable member in a direction to decrease the quantities of the volume variations of the hydraulic chambers increases.

Abstract: A vane pump comprises: a drive shaft that passes through the pump frame; a rotor coupled to the drive shaft that has multiple vanes and rotates within the pump frame in an axial direction about an axis of rotation with an outer rotor surface that has a radius that extends from the axis of rotation; a cam ring within the pump frame that circumscribes the rotor and vanes with a cam ring inner surface; multiple radial tilting pad bearings that support the cam ring; a bearing support ring coupled to the pump frame that generally circumscribes the cam ring and mounts the radial tilting pad bearings; side plates that radially extend from the drive shaft to the pump frame to enclose the rotor and the cam ring with at least one side plate having an inlet port and an outlet port; and means for initiating rotation of the cam ring from rest.

Abstract: A system for controlling fluid flow rates in a transmission includes a pump having variable displacement and providing a pressurized fluid source, a regulating valve communicating with the fluid source and a pressure sensor, the pressure sensor producing a variable control signal whose magnitude represents a degree to which fluid flow requirements of the transmission are being provided by the fluid source, and an actuating valve producing a pressure that changes the pump displacement in response to the magnitude of the control pressure.

Abstract: A variable displacement pump and pump control system therefor to pump a fluid at selected pump output flow rates having a variable displacement pump and a fluid volume displacement selection controller to select a volume of fluid to be forced from the pump inlet to the pump outlet by the rotating member during a rotation thereof. A movable lead screw is coupled to the displacement selection controller so as to be capable of altering the position thereof, and a lead screw positioner is provided for selectively moving, or preventing the moving of, the movable lead screw by extending and retracting the lead screw through a threaded opening.

Abstract: A variable displacement vane pump which includes an enhanced discharge port. The enhanced discharge port reduces areas of high pressure in the discharge port which would otherwise occur as the pressurized working fluid reverses its direction of flow to enter the discharge port. By reducing the areas of high pressure, the back torque on the pump rotor is reduced and the energy efficiency of the pump is enhanced. In one embodiment, the pivot for the pump control ring is located radially outwardly from a conventional location, to allow for a discharge recess to be formed in the control ring, adjacent the discharge port, and extending past the pivot to the pump outlet. In a second embodiment, the discharge recess is formed in the control ring around the pivot and a seal is provided on the control ring to inhibit leakage of pressurized working fluid past the control ring.

Abstract: A variable displacement vane pump provides a substantially constant output pressure in its regulated operation region. A longitudinal axis of the control spring is inclined, with respect to a plane through the rotational axis of a pivot and a contact point between the control ring and the control spring. The inclination reduces the length of the moment arm between the spring and the pivot when the control ring of the pump is moved from the maximum displacement position to the minimum displacement position. The reduced length moment arm offsets the increase in the moment produced by compression of the control spring is offset to achieve a substantially constant output pressure. The control spring is compressed a reduced amount during pump operation to minimize the change in output force exerted by the control spring as the control ring moves between positions.

Abstract: A variable capacity vane pump has a pump control ring which is moveable to alter the volumetric displacement of the pump. The pump ring is moved by at least first and second control chambers, which acts on the pump control ring when pressurized working fluid is supplied to them to move the pump control ring to alter the volumetric capacity of the pump. When pressurized fluid is supplied to only one control chamber, the pump operates at a first equilibrium pressure and when pressurized fluid is also supplied to the second chamber, the pump operates at a second equilibrium pressure. If desired, pressurized fluid can also be supplied only to the second control chamber to operate the pump at a third equilibrium pressure and/or additional control chambers can be provided if required.