Abstract: A variable displacement vane pump having a vaned rotor adjustably contained within a cam member for rotation between fuel inlet and fuel discharge arcs. Adjacent vanes form enclosed fuel bucket areas which are expanded and axially-supplied with fuel in the fuel inlet arc and are contracted and axially-discharge the fuel in the fuel discharge arc. Fuel circulation is improved by providing a central recess at each vane tip and/or a central groove in the cam surface to prevent trapping, stagnation and overheating of fuel at the centerpoints of the bucket areas, which overheating can result in expansion of the vane tips, scoring of the cam surface and pump failure.

Abstract: A durable, single action, variable displacement vane pump capable of undervane pumping, components thereof, and pressure balancing method. The pump comprises a cylindrical barstock rotor member having large diameter journal ends and central vane slots uniformly spaced therearound. The vane slots are elongate and have a central vane-supporting portion of maximum depth surrounded at each end by extension portions having depths which decrease axially to the surface of rotor member. The vaned rotor is rotatably supported within a unitary cam member having opposed faces and a circular bore therethrough forming a cam chamber having a continuous interior circular cam surface. The vane slot extensions in the rotor project outwardly beyond the cam chamber.

Abstract: The fuel pumping system for delivering fuel to an engine includes a fuel transfer circuit for directing fuel from a fuel supply tank to the engine, a fuel boost pump, a main fuel pump and an accumulator device positioned along the transfer circuit between the boost pump and the engine for accumulating fuel and vapor so as to provide a reserve supply of fuel to the engine while minimizing the amount of undissolved vapor delivered to the engine. The system includes a return passage communicating, at one end, with the accumulator and at an opposite end with the fuel transfer circuit upstream of the boost pump for directing fuel and vapor from the accumulator into the transfer circuit.