초록 ▼

For use with a variable displacement piston type pump, a valve responsive to pump discharge manifold pressure for controlling the pressure in the pump chamber, and which controlled pressure creates a force for regulating the stroke of the pump pistons to maintain a predetermined substantially consta

For use with a variable displacement piston type pump, a valve responsive to pump discharge manifold pressure for controlling the pressure in the pump chamber, and which controlled pressure creates a force for regulating the stroke of the pump pistons to maintain a predetermined substantially constant pressure with a variable flow of fluid through the pump.

대표청구항 ▼

A pressure control valve for a pump having a relatively high discharge pressure, comprising: a valve cylinder having a bore extending at least partially therethrough; a pressure inlet port extending external to the valve and communicating with the valve cylinder bore and the pump whereby the relativ

A pressure control valve for a pump having a relatively high discharge pressure, comprising: a valve cylinder having a bore extending at least partially therethrough; a pressure inlet port extending external to the valve and communicating with the valve cylinder bore and the pump whereby the relatively high pump discharge pressure is transmitted to the valve; a spring loaded valve spool disposed within the valve cylinder bore and responsive to the relatively high pump discharge pressure transmitted to the valve for being displaced against the spring load; first and second orifices disposed substantially apart from communicating with separate portions of the valve cylinder bore, the first orifice communicating with the portion of the valve cylinder bore communicating with the pressure inlet port and said first and second orifices disposed relative to the valve spool so that the displacement of the valve spool increases the area of one of the orifices and decreases the area of the other of the orifices; a channel in communication with the first and second orifices, with a relatively intermediate control pressure being created in the channel and a relatively low pressure being created in the portion of the valve cylinder bore communicating with the other orifice upon the area of the one orifice increasing and the area of the other orifice decreasing; a first pressure outlet port extending external to the valve and communicating with the channel and the pump whereby the relatively intermediate control pressure is transmitted to the pump; and a second pressure outlet port extending external to the valve and communicating with the portion of the valve cylinder bore communicating with the other orifice and communicating with the pump, whereby the relatively low pressure is transmitted to the pump.