Patent ID: 7350616

Claim:
A power steering pump comprising: a housing, which includes a bore having an axis, a fluid discharge port communicating with said bore at a first axial location, a fluid bypass port communicating with said bore at a second axial location with an inlet through which fluid enters said bypass port from said bore, and a fluid outlet passage at a first end of said bore communicating with said fluid discharge port and said bore; a cylindrical flow control valve located at a second end of said bore, having first and second ends with said first end extending into said bore and said valve being axially displaceable along said axis from a first location in which said bypass port inlet is in an unobstructed open condition and into other locations within a defined range which cause a corresponding degree of interruption of fluid flow into said bypass port inlet, including a fully obstructed closed condition; an actuator element rigidly secured via a rod element to said second end of said flow control valve and being axially displaceable with said rod element and said valve along said axis in response to forces being applied thereto; a coil spring about said rod element, said spring being seated between said housing at said second end of said bore and said actuator element to provide a bias force against said actuator element and to place said flow control valve in said first location in the absence of other opposing forces; and an electromagnetic coil mounted to said housing and surrounding said actuator element for generating an electromagnetic field that applies electromagnetic forces to move said actuator element, said rod element and said flow control valve along said axis against the bias forces of said spring to position said flow control valve at locations within said range; and wherein said flow control valve, said rod element and said actuator element each have a continuous open fluid passage coaxially located in each to extend from said first end of said valve and through said actuator element to be in communication with fluid in said bore.