Power-steering pump

摘要

The present invention discloses a power-steering pump which may reduce in a very stable manner the flow rate of the hydraulic liquid under pressure to be delivered to a power steering system with increase of the rotational speed of an engine beyond an idling speed and which may easily change the above rate reduction or attenuation characteristic depending upon the types of the automotive vehicles and power steering systems thereof. A flow-control valve which is disposed in parallel with the axis of a pump mechanism is provided with a variable-area orifice which determines the flow rate attenuation characteristic and which is defined by an orifice groove cut through a flange of a partition wall member and an enlarged-diameter portion at the free end of a control rod extended through the partition wall member from the front end of a control spool of the flow-control valve. The flow-control valve is so arranged as to be freely detached from the pump independently of the pump mechanism so that a partition wall member having a suitable orifice groove may be placed, thereby changing the flow-rate attenuation characteristic as needs demand.