Patent attributes
An apparatus (10) comprises a pump (12) and a pressure compensating valve (94). The pump (12) includes a member (22) having a surface (24) defining a pumping chamber. A rotatable rotor (30) is located in the pumping chamber. The rotor (30) has circumferentially spaced vane-like members (42) defining pumping pockets (48) that expand and contract during rotation of the rotor (30). The pump (12) has a fluid circuit (72) providing fluid pressure for biasing the vane-like members (42) of the rotor (30) radially toward the surface (24). The pressure compensating valve (94) controls fluid flow through an outlet (16) and also controls the pressure in the fluid circuit (72). The pressure compensating valve (94) has an initial condition blocking fluid flow through the outlet (16) at pump start-up to provide fluid pressure in the fluid circuit (72) to bias the vane-like members (42) of the rotor (30) radially toward the surface (24).
