Patent ID: 6478549
Filing Date: 2002-11-12
Classification: F04C

Abstract:
A hydraulic fluid pump for use with a fluid powered system comprising:a first pump discharge outlet for delivering fluid to the system from the pump; a pump inlet port for accepting fluid from the system; a vane assembly including a rotor, a cam, and a plurality of vanes cooperating to form a plurality of expansible pump chambers for transferring fluid from the inlet port to the first discharge outlet; a first discharge port in fluid communication with the pump chambers and a primary discharge passageway, the primary discharge passageway being in fluid communication with the first discharge outlet and directs fluid thereto from the first discharge port, the primary discharge passageway being exposed to a first system line pressure; a second discharge port in fluid communication with the pump chambers and a secondary discharge passageway, the secondary discharge passageway being in selective communication with the primary discharge passageway and in selective communication with a second discharge outlet connected to a low pressure chamber by a secondary line, the secondary line being exposed to a second system line pressure; and a flow control valve disposed within the secondary discharge passageway, wherein actuation of the flow control valve causes the fluid flowing within the secondary discharge passageway to be directed to the second discharge outlet and through the secondary line to the low pressure chamber of the system.