Compact power steering pump

Abstract

A vane type compact pump for use in a power steering system having a remote reservoir includes a substantially cylindrical housing with a central cylindrical cavity. The cavity has a large opening at one end of the housing and a shaft opening at the other end. A pressure plate, cam, rotor and vane assembly and a thrust plate are axially aligned and positioned in the cavity with the thrust plate being adjacent to and closing the large open end of the cavity. A locking ring engages the housing and limits the axial movement of the thrust plate toward the large open end. A drive shaft is rotatably supported in a bearing in the housing and in a bearing in the thrust plate. The drive shaft is drivingly connected with the rotor intermediate the bearing supports. The fluid discharge from the cam rotor and vane assembly passes through the pressure plate to a space intermediate the pressure plate and housing and then through a flow controlling system which permits a predetermined volume of hydraulic fluid to be delivered to the power steering system. The remaining fluid is redirected to the cylindrical cavity. On its return to the cylindrical cavity, the redirected fluid passes through a portion of an inlet port from which make-up oil is aspirated from the reservoir and a supercharge pressure is established in the cylindrical cavity.