Showa Corporation

Morihito Ichizuki

Kenji Saito

Kenzo Oba

Takeshi Ueki

Yoshinobu Yamada

A relief valve is provided with an elastic body seal sealed into an annular gap between a ball receiver and a valve hole, and is slidably in contact with an inner periphery of the valve hole such that the elastic body seal is not compressed in an axial direction of the ball receiver.

Relief valve

In a variable displacement pump for a power steering device of a vehicle, the adapter ring is arranged to be easily engaged with the engagement hole at the pump casing, to improve ease of assembly. The relationship of the adapter ring with the engagement hole reduces vibration and noise. Also, the reduction and deformation qualities of the adapter ring are increased

Variable displacement pump

In the back pressure groove structure of a variable displacement vane pump comprising a rotor rotatably contained in a pump housing and having a plurality of vane grooves arranged radially and equidistantly in a circumferential direction, a cam ring is arranged in the pump housing in a movable and displaceable manner, fitted into the pump housing to form a pump chamber with an outer peripheral portion of the rotor and applied with an urging force to provide a maximum volume of the pump chamber. A side plate is contained in the pump housing in a non-rotatable manner, slidably contacting with one sides of the rotor and the cam ring and having back pressure grooves communicating with the vane grooves. A cover plate closes an opening of the pump housing, slidably contacting with other sides of the rotor and the cam ring and having a back pressure groove communicating with the vane grooves, the back pressure grooves of the side plate communicate with a high pressure side and are divided back pressure grooves obtained by dividing an annular back pressure groove into a pump suction side groove and a pump discharge side groove. The back pressure groove of the cover plate is an annular back pressure groove or a C-shaped back pressure groove obtained by closing the annular back pressure groove at one of a pump suction side portion and a pump discharge side portion into which the annular back pressure groove is virtually partitioned.

Growing community of inventors

Tochigi, Japan

Morihito Ichizuki