Abstract: A power steering pump includes a housing defining an opening containing a sliding vane rotor, a cam ring and pressure plates located at each axial side of the rotor, inlet ports connected to a source of low pressure fluid, and outlet ports connected to a power steering system. The pressure control valve opens and closes an orifice of constant size connecting the pump outlet to a power steering gear. An electronically variable orifice arranged in parallel with the fixed orifice connects the pump and outlet to the power steering gear. When the control valve opens sufficiently, the pump outlet is connected to the inlet through a diffuser arranged to draw low pressure fluid into a high velocity stream of bypass fluid. An orifice fitting, located in a flow control valve that directs flow from a pump outlet port through the orifice aperture to an automotive power steering gear, diverts that flow to a bypass port connected to the pump inlet. The orifice aperture is offset radially from the axis of the valve.

Abstract: The flow control system includes a flow control valve, an orifice located between the pump outlet port, a passage carrying feedback pressure at a location downstream from the orifice to one side of the valve, and a bypass port located between the pump outlet and the pump inlet. The bypass port opens as a valve spool moves due to differential pressure across the orifice. When pump discharge is low, the valve closes the bypass port; when pump flow rate increases, the valve opens the bypass port. The jet pump effect of a bypass diffuser, located between the bypass port and the pump inlet, supercharges low pressure fluid in a remote reservoir by using kinetic energy in the bypass flow to draw fluid from the reservoir into the pump and to raise static pressure at the pump inlet. A clip having a relatively large wetted surface area in comparison to its cross sectional area is located in a passage connecting the pump outlet and the load.

Abstract: A power steering pump includes a housing defining an opening containing a sliding vane rotor, a cam ring and pressure plates located at each axial side of the rotor and having inlet ports connected to a source of low pressure fluid and outlet ports connected to a power steering system. The pressure control valve opens and closes an orifice of constant size connecting the pump outlet to a power steering gear. An electronically variable orifice arranged in parallel with the fixed orifice connects the pump and outlet to the power steering gear. When the control valve opens sufficiently, the pump outlet is connected to the inlet through a diffuser arranged to draw low pressure fluid into a high velocity stream of bypass fluid. Kinetic energy of the stream is used to increase static pressure in the fluid supplied to the pump inlet.

Abstract: A power steering pump includes a housing defining an opening containing a sliding vane rotor, a cam ring and pressure plates located at each axial side of the rotor and having inlet ports connected to a source of low pressure fluid and outlet ports connected to a power steering system. The pressure control valve opens and closes an orifice of constant size connecting the pump outlet to a power steering gear. An electronically variable orifice arranged in parallel with the fixed orifice connects the pump and outlet to the power steering gear. When the control valve opens sufficiently, the pump outlet is connected to the inlet through a diffuser arranged to draw low pressure fluid into a high velocity stream of bypass fluid. Kinetic energy of the stream is used to increase static pressure in the fluid supplied to the pump inlet.