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 radial pump has a housing with a cylinder ring is pivotally mounted therein. The cylinder ring has a circular aperture within which a cam surface is formed. A cylinder block rotates within the cylinder ring aperture and has a plurality of radially extending cylinders each having port which selectively communicates with a fluid inlet and a fluid outlet as the cylinder block rotates. A plurality of pistons is slideably received within the cylinders and engages the cam surface. An actuator operably coupled to produce movement of the cylinder ring, which alters the spatial relationship between the cylinder ring and the cylinder block to vary the amount that the pistons move within the cylinders. The amount of movement of the pistons within the cylinders is directly related to the magnitude of fluid flow delivered by the pump and moving the cylinder ring thereby controls the fluid flow.

Abstract: A variable displacement vane pump, including a pump body, a driving shaft, a rotor, a cam ring swingable on a swing support surface, first and second plate members on opposite sides of the cam ring, a suction port and a discharge port on a side of at least one of the first and second plate members, a seal cooperating with the swing support surface to divide a space on an outer circumferential side of the cam ring into first and second fluid pressure chambers, a fluid pressure control valve, a stop disposed on the pump body on a side of the first fluid pressure chamber and restricting a swing movement of the cam ring, and a detent disposed between the cam ring and the pump body on a side of the second fluid pressure chamber and preventing a rotational movement of the cam ring around the driving shaft.

Abstract: A variable displacement engine oil vane pump includes a displacement control for controlling displacement of the pump. The control includes a cam ring in a housing pivotally connected to a wall of the housing by a pivot. The cam ring is internally engaged by slide vanes. A control chamber is defined by the cam ring and the housing wall. A control orifice provides for communication of control oil from a pressurized source to the control chamber. A vent chamber is generally opposite the control chamber and is defined by the cam ring and the housing wall. A dump chamber is defined by the cam ring and the housing wall and is generally disposed between the control chamber and the vent chamber. A dump orifice provides for communication between the control chamber and the dump chamber. A vent orifice provides for communication between the vent chamber and the dump chamber.

Abstract: A rotary pump for producing a pressure medium flow for a consumer, includes a pump housing in which a curved ring is inserted. A rotor is rotatably borne on a drive shaft in the curved ring. The rotor carries displacement elements at a tangential distance to one another which form a pump chamber between the rotor and the curved ring with a suction opening. A pressure medium-activated adjusting device is operable for changing the eccentricity of the curved ring relative to the rotor, and includes a first pressure chamber and a second pressure chamber fluidically and tangentially distanced from the first pressure chamber The pressure in the first and second pressure chambers is controlled by a flow control valve, the low pressure chamber of which communicates with a first control line on a downstream side of a metering orifice.

Abstract: A variable displacement pump includes a control valve formed with a high-pressure chamber for introducing therein high-pressure fluid on the upstream side of a metering orifice, a pressure chamber for introducing therein pressure fluid on the downstream side of the metering orifice, a low-pressure chamber arranged between the high-pressure and pressure chambers for introducing therein low-pressure fluid, and a communication passage for providing fluid communication between one of the high-pressure and low-pressure chambers and a first fluid-pressure chamber of the pump.

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: A variable displacement vane pump includes a rotor, a cam ring; and a pump casing including first and second side walls disposed on both sides of the cam ring, and a circumferential wall surrounding the cam ring and defining first and second pressure chambers. A pressure introduction groove is formed in a sliding contact surface between the cam ring and one of the first and second side walls, and arranged so that a pressure lower than an outlet pressure is introduced.

Abstract: In a variable displacement pump, an outer peripheral surface approximately in an opposite side to a portion supported to an oscillation supporting point in a cam ring with respect, to a pump shaft is formed as a convex surface portion holding a seal member brought into slidable contact with an inner peripheral surface of an outer case, and an inner peripheral surface of the outer case with which, the seal member held to the convex surface portion of the cam ring is brought into slidable contact is formed as a circular arc surface around the oscillation supporting point.

Abstract: In a variable displacement pump provided with a high pressure chamber formed at a position facing to a discharge region of a pump chamber between a back surface of a side plate and a pump casing and introducing a pump discharge side pressure oil, a low pressure chamber formed at a position facing to a suction region of the pump chamber between the back surface of the side plate and the pump casing, and communicating with a suction region of the pump chamber, and an annular seal member interposed between the back surface of the side plate and the pump casing, and surrounding the low pressure chamber together with a lubricating oil path around the pump shaft, the annular seal member is provided with a bridge portion connecting both ends of a U-shape of an approximately U-shaped portion of the annular seal member along the lubricating oil path around the pump shaft.

Abstract: A variable-capacity vane pump comprising a body (1) comprising a cavity (2) in which a mobile ring (3) can move, inside which a hub (4) is located which is rotatable around a fixed axis (R) and equipped with vanes (5) which during rotation are supported against an inner face of the mobile ring (3), displacing structure for moving the mobile ring (3) as a function of a control pressure between a position centered on the axis of rotation of the hub (4) and an extreme eccentric position with respect to the axis of rotation of the hub (4). According to the invention, the displacing structure of the mobile ring (3) comprise a recess (10) provided in the wall of the cavity (2) of the body (1), and a projection (9) formed on the outer face of the mobile ring (3) and designed to slide in the recess (10) of the cavity (2) of the body (1) so as to form a control chamber in which the control pressure is applied.

Abstract: A variable displacement pump includes a rear cover and side plate arranged on both sides of a cam ring and making slide contact with the cam ring. The rear cover has an end face on the side of the cam ring, which is formed with a suction port. A seal member is arranged in a chamber formed between a pump housing and the cam ring and for dividing the chamber into two portions that define first and second working chambers. A connection groove and terminal groove are formed in the end face of the rear cover to provide fluid communication between the suction port and the second working chamber.

Abstract: A variable displacement vane pump includes: a cam ring defining first and second fluid pressure chambers on both sides thereof; and a rotor mounted inside the cam ring, the rotor defining an annular chamber outside thereof. Arranged outside of the rotor, vanes divide the annular chamber into a plurality of pump chambers. A suction port is defined in a section of the annular chamber in which each of the pump chambers expands with the rotation of the rotor, while a discharge port is defined in a section of the annular chamber in which each of the pump chambers contracts with the rotation of the rotor. A first fluid passage is connected to one of the first and second fluid pressure chambers. A second fluid passage is connected to one of the suction port and the discharge port. An electromagnetic valve controls fluid communication between the first and second fluid passages.

Abstract: A rotating vane vacuum pump has a secondary inlet (4) which permits additional suction after the primary inlet (3) has closed.

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: A multi-layered compressor housing and method of manufacture is provided. The housing defines an interior space and includes first and second layers having first and second major surfaces respectivley. The first and second layers are secured together by the frictional engagement of the first and second major surfaces which each substantially enclose the interior space defined by the housing. The housing may be manufactured by placing first and second layers of sheet stock material in mutual facing engagement wherein the two layers are relatively moveable. The first and second relatively moveable layers are then simultaneously formed into a non-planar shape defining at least a portion of the housing. A compressor is then mounted in the housing and the housing is hermetically sealed. The simultaneous forming of the first and second layers into a non-planar shape causes the frictional engagement of the layers whereby the layers are secured together.

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: A fluid moving device with a heat radiation, which is mounted to a conductive part to dissipate heat from a heat generation part under the fluid moving device and another heat generation part around the first heat generation part, includes a first frame member, which has an area thereof being equal to that of the conductive part and a base member being movably attached with the fan wheel, and a second frame member, which has a second hollow part with an area thereof being greater than the first frame member and provides a projection section extending beyond four sides of the first frame member. Once the fan wheel rotates, the fluid is dragged to enter the fluid moving device via the second hollow part and to leave via the first hollow part so as to dissipate heat in and around the conductive part.

Abstract: A vane pump is disclosed for use with gas turbine engines which has pressurized fluid supplied to the undervane portion of the vane elements to balance the forces imparted thereon. The vane pump includes a pump housing, a cam member, a cylindrical rotor member and a chamber. The chamber is defined within the housing and positioned for fluid communication with the undervane portion of each vane element to provide a desired pressure thereto. The chamber is in fluid communication with a first pressure source and a second pressure source, wherein the first pressure source is associated with the discharge arc segment of the pumping cavity, and the second pressure source is associated with the inlet arc segment of the pumping cavity.

Abstract: An oil pump unit includes an additional outlet port connected to the downstream side of the pump through the pump cover. With this additional port, the oil pump unit is able to have electronic vacuum and pressure sensors upstream and downstream of the pump for remote monitoring of the pump. The invention is particularly suited for oil pump units which have a main discharge outlet port through the one side of the pump body and a main inlet port through an opposing side of the pump cover. The invention is also particularly suited for oil pump units having a solenoid valve mounted at the top side of the pump body which prevents installation of a pressure sensor along the top side.

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: 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: An auxiliary solenoid controlled variable displacement power steering pump, hydraulic systems incorporating same, and method for improving the efficiency of variable displacement power steering pumps. In one embodiment, a rotor is arranged within a pump body, and a cam fitted on an outer periphery of the rotor and movably arranged within the pump body to form a variable volume pump chamber. The cam is biased towards a position within the pump body to create maximum displacement. A mechanism is provided for forcing the cam into a position of fixed minimum or reduced displacement under certain conditions, such as low engine speed and power steering demand. In a preferred embodiment, the mechanism comprises a solenoid driven connecting rod that is operatively connected to the cam. Activation of the solenoid forces the cam to a position of fixed minimum or reduced displacement.

Abstract: A variable displacement vane-type fluid pump is provided which permits improved regulation of the pump discharge such that the pump can meet the various requirements of lubrication for internal combustion engines at all speeds with minimized use of power. Of course, the vane pump may also be utilized in a wide range of power transmission and other fluid distribution applications. The variable displacement vane pump of the invention may utilize both hydrostatic and mechanical assistance in radially positioning its vanes to ensure efficient and quiet operation of the pump and to facilitate priming of the pump. The vane pump of the invention may also use both hydrostatic and mechanical actuators to control the position of its containment ring or eccentric ring and hence, regulate the output of the pump.

Abstract: The hybrid compressor apparatus is composed of a compressor in which fluid is compressed by varying a volumetric capacity of a compression space provided between a first compression member and a second compression member, which are movable independently of each other, according to rotation of the first compression member relative to the second compression member, a motor rotatable upon receipt of power of an external electric source, and a driven member rotatably driven by motive force transmitted from an external driving source. The first compression member is connected with the driven member and the second compressor is connected with the motor. If maximum discharge amount is required for the compressor, the motor is driven separately by a control device when the driven member drives the first compression member so that the second compression member is rotated in a direction opposite to that of the first compression member.

Abstract: A fuel metering unit including a pump having a rotor with a plurality of slots. The pump also includes a pivotally movable cam ring coaxially arranged with respect to the rotor. Vanes are slideably disposed in the slots for maintaining contact with the cam ring during movement thereof. A servovalve has a motor and nozzles operatively connected to the pump such that increased flow through the first nozzle pivots the ring of the pump toward maximum while increased flow through the second nozzle pivots the ring toward minimum. An arm extends between the nozzles for varying fluid flow therethrough. The arm couples to the motor such that the motor moves the arm. A flow meter connects to the pump and an end of the arm for applying a force against the arm to assist in maintaining position of the arm.

Abstract: A variable displacement pump is provided. A pump body has an outer ring defining an inner cavity, where the inner cavity further defines a pump suction path and a pump discharge path in fluid communication with the inner cavity. A cam ring is pivotably supported in the inner cavity by a pivot pin formed on a portion of an inner diameter of the adapter ring. An actuated cam is formed on the cam ring. An actuator is linked through the actuated cam to the cam ring for moving the cam ring in a pivotable motion. A control module is linked to the actuator.

Abstract: A variable displacement vane-type fluid pump is provided which permits improved regulation of the pump discharge such that the pump can meet the various requirements of lubrication for internal combustion engines at all speeds with minimized use of power. Of course, the vane pump may also be utilized in a wide range of power transmission and other fluid distribution applications. The vane pump of the invention may also use both hydrostatic and mechanical actuators to control the position of its containment ring or eccentric ring and hence, regulate the output of the pump. According to yet another aspect of the present invention, to prevent inlet flow restriction or cavitation, a valve may be provided to permit some of the pump outlet or discharge flow to bleed into the pump inlet to provide needed velocity energy to the fluid flow into the pump inlet.

Abstract: A fuel metering unit including a pump having a rotor with a plurality of slots. The pump also includes a pivotally movable cam ring coaxially arranged with respect to the rotor. Vanes are slideably disposed in the slots for maintaining contact with the cam ring during movement thereof. A servovalve has a motor and nozzles operatively connected to the pump such that increased flow through the first nozzle pivots the ring of the pump toward maximum while increased flow through the second nozzle pivots the ring toward minimum. An arm extends between the nozzles for varying fluid flow therethrough. The arm couples to the motor such that the motor moves the arm. A flow meter connects to the pump and an end of the arm for applying a force against the arm to assist in maintaining position of the arm.

Abstract: A first fluid pressure chamber 21 is provided in one of the swing directions of a cam ring 8 and a second fluid pressure chamber 22 is provided in the other direction, with a spring 17 for urging the cam ring 8 toward the second fluid pressure chamber 22. Within the 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 vale 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.

Abstract: A pump system with a hydraulic pump has a control element, which affects the pump output and to which control signals of a regulating and control unit can be supplied for adjustments.

Abstract: First and second fluid pressure chambers are formed in both sides of a movement direction of a cam ring swingably placed within a pump body. A spool of a control valve is moved due to a pressure difference between the front and back of a metering orifice. Fluid pressures of the fluid pressure chambers are controlled. The cam ring is swung. Further, a solenoid for giving thrust in an axial direction thereof to the spool of the control valve and electronic control device for controlling driving of the solenoid are provided. The electronic control device has a steering sensor and determines a steering direction based on a signal from the steering sensor and also calculates a steering speed to the steering direction and controls a driving current of the solenoid in response to this steering speed and changes a discharge flow rate of a pump.

Abstract: The invention relates to a vane-cell pump comprising a pump rotor (20), provided with a radially displaceable rotor blade (22). Said pump rotor is mounted in a pump stator (12) which can be pivoted inside a pump bearing house (10) around a stationary pivotal axis (34) in a radial position with regard to said pump rotor. A control device (30) is associated with the pump stator (12) for automatic pressure adjustment. Said control device has an actuating member protruding on the outside, therefrom, perpendicular to the pivotal axis thereof. The actuating member forms a pivoting piston (38) in a guide element (10) of the pumpbearing housing (10) which is directly impinged upon by a pumping medium. The pivotable piston can pivot in a direction against the action of a pressure spring (50).

Abstract: An integrated speed reducer and gerotor pump is disclosed. The device comprises a motor, a speed reducer, and a gerotor pump. The motor provides torque at an elevated speed. The speed reducer is coupled with the motor and converts the torque at an elevated speed into torque at a reduced speed. The gerotor pump is coupled with the speed reducer and uses the torque at the reduced speed for pumping fluids.

Abstract: In a variable displacement pump, a pressurizing cylinder is provided on 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. An oil chamber of the pressurizing cylinder is interposed in a pump discharge side passage, and wherein a pressure in an upstream side of the main throttle 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 main throttle is introduced to the second fluid pressure chamber.

Abstract: A vane pump is disclosed for use with gas turbine engines which has pressurized fluid supplied to the undervane portion of the vane elements to balance the forces imparted thereon. The vane pump includes a pump housing, a cam member, a cylindrical rotor member and a chamber. The chamber is defined within the housing and positioned for fluid communication with the undervane portion of each vane element to provide a desired pressure thereto. The chamber is in fluid communication with a first pressure source and a second pressure source, wherein the first pressure source is associated with the discharge arc segment of the pumping cavity, and the second pressure source is associated with the inlet arc segment of the pumping cavity.

Abstract: A vane pump is disclosed for use with gas turbine engines which has pressurized fluid supplied to the undervane portion of the vane elements to balance the forces imparted thereon. The vane pump includes a pump housing, a cam member, a cylindrical rotor member and a chamber. The chamber is defined within the housing and positioned for fluid communication with the undervane portion of each vane element to provide a desired pressure thereto. The chamber is in fluid communication with a first pressure source and a second pressure source, wherein the first pressure source is associated with the discharge arc segment of the pumping cavity, and the second pressure source is associated with the inlet arc segment of the pumping cavity.

Abstract: A fuel metering unit including a pump having a rotor with a plurality of slots. The pump also includes a pivotally movable cam ring coaxially arranged with respect to the rotor. Vanes are slideably disposed in the slots for maintaining contact with the cam ring during movement thereof. A servovalve has a motor and nozzles operatively connected to the pump such that increased flow through the first nozzle pivots the ring of the pump toward maximum while increased flow through the second nozzle pivots the ring toward minimum. An arm extends between the nozzles for varying fluid flow therethrough. The arm couples to the motor such that the motor moves the arm. A flow meter connects to the pump and an end of the arm for applying a force against the arm to assist in maintaining position of the arm.

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 fuel metering unit including a pump having a rotor with a plurality of slots. The pump also includes a pivotally movable cam ring coaxially arranged with respect to the rotor. Vanes are slideably disposed in the slots for maintaining contact with the cam ring during movement thereof. A servovalve has a motor and nozzles operatively connected to the pump such that increased flow through the first nozzle pivots the ring of the pump toward maximum while increased flow through the second nozzle pivots the ring toward minimum. An arm extends between the nozzles for varying fluid flow therethrough. The arm couples to the motor such that the motor moves the arm. A flow meter connects to the pump and an end of the arm for applying a force against the arm to assist in maintaining position of the arm.

Abstract: A variable displacement vane pump comprises a pump body having inlet and outlet ports, a rotor driven by a drive shaft and co-axially aligned therewith, a plurality of radially extending vanes slidably disposed in the rotor, and a slide pivotally disposed on a pivot in the pump body and having a central axis eccentric to the axis of the rotor. A plurality of fluid chambers are defined by the rotor, vanes, and slide. A spring acts on the slide to urge the slide in one direction. A regulating chamber is configured as a semi-circular cylinder intermediate the pump body and an outer surface of the slide, wherein a pressure regulating valve pressurizes the regulating chamber to pivot the slide against the force of the spring to decrease the volume of the fluid chambers. The slide includes a slide channel formed in a face to channel fluid leakage from the fluid chambers away from the regulating chamber.

Abstract: A variable displacement vane pump comprises a pump body having inlet and outlet ports, a rotor driven by a drive shaft and co-axially aligned therewith, a plurality of radially extending vanes slidably disposed in the rotor, and a slide pivotally disposed on a pivot in the pump body and having a central axis eccentric to the axis of the rotor. A plurality of fluid chambers are defined by the rotor, vanes, and slide. A spring acts on the slide to urge the slide in one direction. A regulating chamber is configured as a semi-circular cylinder intermediate the pump body and an outer surface of the slide, wherein a pressure regulating valve pressurizes the regulating chamber to pivot the slide against the force of the spring to decrease the volume of the fluid chambers. The slide includes a slide channel formed in a face to channel fluid leakage from the fluid chambers away from the regulating chamber.

Abstract: A heat dissipation fan has a casing, two fans and multiple stationary blades. The fans are co-axially rotatably mounted in the casing. Multiple rotating blades are arranged around the outer periphery of each fan. The stationary blades are secured in the casing and between the rotating blades of the two fans. The angle of the rotating blades on both of the fans is the same. The angle of the stationary blades is perpendicular to that of the passing rotating blades. Accordingly, the airflow generated by the dissipation fan will be enhanced with the multiple layers of rotating blades. The stationary blades reverse the direction of the airflow. The dissipating effect of the dissipation fan is further increased.

Abstract: In a variable displacement pump, a relief valve is constituted by a pilot drive type relief valve obtained by adding a pilot valve to a main valve, a fluid pressure in a downstream side of a metering orifice provided in a pump discharge side passage is applied to the pilot valve, and the main valve is capable of opening and closing a downstream side passage of the metering orifice with respect to a drain passage.

Abstract: A pump including a pump chamber 18, formed in a pump body 11, between a cam ring 17 and a rotor 15. The cam ring is formed so as to move in a direction whereby the pump capacity of the pump chamber increases and decreases. First and second fluid pressure chambers 33 and 34 are formed at opposite sides of the cam ring 17. The pump has a spool that is axially moved by a difference in fluid pressure between upper and lower stream sides of a metering throttle 50 connected to a discharge side passage 27 of the pump chamber. The spool is part of a control valve 30 that controls fluid pressure in at least the first fluid pressure chamber. An electronic driving unit, for example, a solenoid 60, applies axial thrust to the spool of the control valve.

Abstract: A variable displacement vane-type fluid pump is provided which permits improved regulation of the pump discharge such that the pump can meet the various requirements of lubrication for internal combustion engines at all speeds with minimized use of power. Of course, the vane pump may also be utilized in a wide range of power transmission and other fluid distribution applications. The vane pump of the invention may also use both hydrostatic and mechanical actuators to control the position of its containment ring or eccentric ring and hence, regulate the output of the pump. According to yet another aspect of the present invention, to prevent inlet flow restriction or cavitation, a valve may be provided to permit some of the pump outlet or discharge flow to bleed into the pump inlet to provide needed velocity energy to the fluid flow into the pump inlet.

Abstract: In a variable displacement pump, a pressurizing cylinder is provided on 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. An oil chamber of the pressurizing cylinder is interposed in a pump discharge side passage, and wherein a pressure in an upstream side of the main throttle 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 main throttle is introduced to the second fluid pressure chamber.

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: In a variable capacity type pump, in the inner diameter of a cam ring, an inner diameter of a portion forming a middle section between a suction section and a discharge section in a pump chamber is constituted by a negative slope curve in which an end portion of a suction port is set to be a start point, and a complete round curve and a negative slope curve are connected by a high-order curve.

Abstract: A scroll-type machine is disclosed which is particularly well suited for use as a compressor in refrigeration and air conditioning systems and incorporates a unique arrangement for modulating the capacity thereof. In one group of embodiments the capacity of the scroll-type machine is modulated by relative axial movement between the scroll members so as to form a leakage path across the wrap tips and opposed end plates. In another group of embodiments, modulation is achieved by reducing the orbital radius of one of the scroll members to thereby form a leakage path across the flank surfaces of the wraps. In the second group, a plurality of pin members are moveable from a first and second positions. In a first position the plurality of pin members operably enable the scroll members to orbit and in a second position the pin members restrict the orbiting motion of the first scroll members.