Hitachi, Ltd.

Unisia Jkc Steering Co., Ltd.

Hideo Konishi

Shigeaki Yamamuro

Fusao Semba

Kazuyoshi Uchino

Haruo Okamoto

Sigeaki Yamamuro

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.

Variable capacity vane pump

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.

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.

Variable displacement vane pump

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.

Pump apparatus

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.

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.

Growing community of inventors

Osato-gun, Japan

Hideo Konishi