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 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 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 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: 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 vane pump, including a pump body, a driving shaft, a rotor, a cam ring swingable around a swing fulcrum, first and second support members on opposite axial sides of the cam ring, a suction port and a discharge port disposed on at least one of the support members, a seal dividing a space on an outer circumferential side of the cam ring into a first fluid pressure chamber defined in a direction in which the cam ring is swung to cause increase in a flow rate of a working fluid discharged, and a second fluid pressure chamber defined in a direction in which the cam ring is swung to cause decrease in the flow rate of the working fluid discharged, and a plunger biasing the cam ring from a side of the second fluid pressure chamber toward a side of the first fluid pressure chamber.

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: 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 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 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 vane pump has a pump body, a driving shaft rotatably supported by the pump body, a rotor rotatably driven by the driving shaft, a plurality of vanes radially extendably installed in respective slots arranged in a circumferential direction in the rotor, a cam ring rockably provided inside the 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. At an outer circumference side of the cam ring inside the pump body, a seal member is provided and defines 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. Then, a control valve controls only a pressure of the second hydraulic pressure 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 variable displacement vane pump, including a pump body, a driving shaft, a rotor, a cam ring swingable around a swing fulcrum, first and second support members on opposite axial sides of the cam ring, a suction port and a discharge port disposed on at least one of the support members, a seal dividing a space on an outer circumferential side of the cam ring into a first fluid pressure chamber defined in a direction in which the cam ring is swung to cause increase in a flow rate of a working fluid discharged, and a second fluid pressure chamber defined in a direction in which the cam ring is swung to cause decrease in the flow rate of the working fluid discharged, and a plunger biasing the cam ring from a side of the second fluid pressure chamber toward a side of the first fluid pressure chamber.

Abstract: A variable displacement pump has a cam ring, a rotor, a plurality of vanes, a pressure plate and a rear body. The cam ring is accommodated within a pump body. The rotor rotates within the cam ring. The plurality of vanes are inserted retractably into slits formed at regular intervals circumferentially in the rotor. The pressure plate and the rear body carry the cam ring and the rotor. A circular groove communicating to a back pressure inlet bore on a bottom portion of the slits is formed in a suction area on a face of the rear body on a side of the rotor. The groove is communicated via a communication passage to a passage between a power steering gear and a tank T to introduce a working oil after used in the power steering gear.

Abstract: A variable displacement pump has a cam ring, a rotor, a plurality of vanes, a pressure plate and a rear body. The cam ring is accommodated within a pump body. The rotor rotates within the cam ring. The plurality of vanes are inserted retractably into slits formed at regular intervals circumferentially in the rotor. The pressure plate and the rear body carry the cam ring and the rotor. A circular groove communicating to a back pressure inlet bore on a bottom portion of the slits is formed in a suction area on a face of the rear body on a side of the rotor. The groove is communicated via a communication passage to a passage between a power steering gear and a tank T to introduce a working oil after used in the power steering gear.

Abstract: Hydraulic oil supplied from pumps (12),(13) to an attachment actuator (60) is controlled by attachment control valves (27),(28). Hydraulic oil supplied from pumps (12),(13) to other actuators (52),(54),(56),(58) is controlled by other control valves (21) through (26). Control conditions for operating the attachment actuator (60) alone and control conditions for operating the attachment actuator (60) simultaneously with any of the other actuators (52),(54),(56),(58) are discriminated by the pilot pressure sensors (32),(34),(36),(38). Control characteristics of the attachment control valves (27),(28) are controlled by a controller (43) based on the discriminated control conditions.

Abstract: Disclosed herein is a hydraulic-pump controller that is capable of controlling absorbed pump torque in good balance against engine output at all times. In this hydraulic-pump controller, the discharge flow rates of the operating oil that are discharged from hydraulic pumps (9, 10) according to manipulation of manipulation units (12, 13) are predicted based on the discharge pressure of the hydraulic pumps (9, 10) that are driven by an engine (1), and based on the manipulation amount of the manipulation units (12, 13) that manipulate hydraulic actuators (27, 28), or a physical quantity correlating with the manipulation amount. Based on the predicted discharge flow rates and the discharge pressure, the absorbed torque of the hydraulic pumps is computed. Then, the predictive engine speed of the engine (11) is computed from the absorbed torque of the hydraulic pumps (9, 10) computed.

Abstract: Hydraulic oil supplied from pumps (12),(13) to an attachment actuator (60) is controlled by attachment control valves (27),(28). Hydraulic oil supplied from pumps (12),(13) to other actuators (52),(54),(56),(58) is controlled by other control valves (21) through (26). Control conditions for operating the attachment actuator (60) alone and control conditions for operating the attachment actuator (60) simultaneously with any of the other actuators (52),(54),(56),(58) are discriminated by the pilot pressure sensors (32),(34),(36),(38).

Abstract: A cam ring 10 is slidably supported within a pump body 2, and a rotor 20 is rotatably disposed inside the cam ring. The cam ring is eccentric to a rotation shaft 22 of the rotor. The rotor carries a plurality of vanes 18 that can be advanced or retreated, in which a pump chamber 24 is formed in a space between the cam ring and the rotor. The cam ring is formed with the first and second fluid pressure chambers 14 and 16 on both sides thereof, and biased in a direction where the displacement of the pump chamber is at maximum by a spring 26. A control valve 28 is provided in which a differential pressure across a metering orifice is applied on both ends of a spool 32 and a spring 36 is disposed on the side of an end face where a downstream fluid pressure is applied. The fluid pressures of the fluid pressure chambers 14 and 16 are controlled by means of the control valve, whereby the cam ring is swung.