Jidosha Kiki Co., Ltd.

Bosch Braking Systems Co. Ltd.

Unisia Jkc Steering Systems Co., Ltd.

Hideo Konishi

Tadaaki Fujii

Hiroshi Nishikiori

Toyoji Takebuchi

Junkichi Odai

A cam ring is slidably supported within a pump body and a rotor is rotatably disposed inside the cam ring. The cam ring is eccentric to a rotation shaft of the rotor. The rotor carries a plurality of vanes that can be advanced or retreated, in which a pump chamber 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 and on both sides thereof, and biased in a direction where the displacement of the pump chamber is at maximum by a spring A control valve is provided in which a differential pressure across a metering orifice is applied on both ends of a spool and a spring is disposed on the side of an end face where a downstream fluid pressure is applied. The fluid pressures of the fluid pressure chambers and are controlled by means of the control valve, whereby the cam ring is swung. A piston that is moved in accordance with an increase in working pressure of a power steering apparatus is provided. This piston exerts an axial thrust to an end face of the spool on the spring side.

Variable displacement pump

A pump including a pump chamber formed in a pump body between a cam ring and a rotor 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 and are formed at opposite sides of the cam ring 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 connected to a discharge side passage of the pump chamber. The spool is part of a control valve that controls fluid pressure in at least the first fluid pressure chamber. An electronic driving unit, for example, a solenoid applies axial thrust to the spool of the control valve.

Variable displacement pump including a control valve

An oil pump includes pump constituent elements, a pump body, and a driving shaft. The pump constituent elements define a pump chamber between a rotor and a cam ring that houses the rotor. The pump body is constituted by a front body and a rear body. The front body defines a housing space for housing the pump constituent elements. The driving shaft extends through and is axially supported by the front body to rotatably drive the rotor. An annular space is formed around the driving shaft in the front body, between a bearing for rotatably driving the driving shaft of the front body, and the pump chamber of the pump constituent elements. A flow control valve is placed in the annular space to return part of a pump discharge fluid from the pump chamber to a pump suction side.

Oil pump

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

A cushioning material sheet to be interposed between a rack support and a press plug for applying an elastic force provided by a spring is formed such that at least its one end face is tapered. Slide-contact surfaces of the rack support and the press plug to be brought into contact with the two end faces of the cushioning material sheet are so formed as to move the cushioning material sheet in a direction perpendicular to a rack support direction, along which the thickness of the cushioning material sheet is decreased. A biasing member is provided to bias the cushioning material sheet in this direction of movement, thereby obtaining a proper meshed condition between a pinion and a rack.

Rack-and-pinion steering apparatus

An electric power steering apparatus includes a gear wheel on a driven side having a gear portion on one side surface thereof on a steering shaft and a pinion to be laterally meshed with a gear portion of the gear wheel on a shaft capable of transmitting a rotational driving force from an electric motor. The gear wheel and the pinion constitute a gear mechanism for transmitting a rotational force as a gear pair with non-parallel, non-intersecting axes. The gear wheel is axially supported on the steering shaft so as to be coupled in only a rotational direction and movable in an axial direction of the shaft. A biasing unit is provided on the other side of the gear wheel opposite to a portion of the pinion to be meshed with the gear portion and laterally urges the gear wheel toward the pinion.

Electric power steering apparatus

A device for improving the starting response of a vane pump and for reducing the power loss during a high speed operation of the pump. The vane pump includes a rotor formed with slits, in which slits vanes are slidably disposed. To drive the respective vanes into abutment against a cam ring, a pair of plates which hold the rotor and the cam ring sandwiched therebetween are formed with a plurality of arcuate grooves, into which a discharged oil is introduced. Rather than providing a narrow groove formed in the same plate as that in which the arcuate grooves are formed to provide a communication therebetween, an annular groove is formed in the lateral surface of the rotor to replace the narrow groove or in addition to the narrow groove, and is constructed so that the narrow groove is interrupted by the vanes as the vanes retract, the annular groove providing a communication between the arcuate grooves when a respective vane is driven radially outwardly.

Vane pump with annular groove in rotor which connects undervane chambers

A power steering valve system includes an input shaft and an output shaft which are aligned on a common axis, and also includes a control valve mechanism which is located offset from the axis in order to reduce the overall length of the valve system. The control valve mechanism includes a spool valve, a displacement of which from its neutral position controls the flow of a hydraulic oil from an oil pump to or from a power cylinder to assist in directing the steerable road wheels in a given direction. The input and output shafts are operatively associated with a motion translating mechanism which translates the magnitude of a relative torsion between the two shafts into a linear displacement. The motion translating mechanism is operatively associated with the spool valve to displace it from the neutral position in accordance with the magnitude of relative torsion between the two shafts.

Growing community of inventors

Saitama, Japan

Hideo Konishi