Hydraulic constant flow gear pump flow control valve

摘要

The hydraulic gear pump (1,2) has a suction inlet (4) and an outlet (5) that connects with a flow regulating valve (6) to deliver a constant flow rate (Q1) to a load. Any surplus flow (Q2) is directed to a second load. The flow regulating valve has a control spool (9) that is moved axially against a spring (10). Within the spool is a variable metering orifice (11) that has a constant pressure difference across it and controls the spool movement to regulate the flow. The pressure drop across a restrictor (20) formed by a hole (15) in a sealing screw controls a switch over valve (8).