Patent ID: 6533556
Filing Date: 2003-03-18
Classification: F04C

Abstract:
A hydraulic pump comprisinga) a housing, b) a pumping element rotatable in said housing including a rotor with a plurality of vanes extending between said rotor and said housing to define pumping chambers between said housing and said pumping element, c) at least a pair of inlets to provide for ingress of fluid through said housing into respective ones of said pumping chambers, d) at least a pair of outlets associated with each of the inlets to provide a plurality of outlet pairs to permit egress of fluid from said pumping chambers, said rotor and housing being arranged such that radial spacing between said rotor and said housing increases as the vanes transverse said inlets, remains constant between said outlets of each outlet pair and decreases as the vanes transverse each of said outlets, said pairs of outlets being uniformly distributed about said housing to balance pumping forces across the pumping element, and e) a first inner port fluidly coupled to a first outlet of a respective one of said pair of outlets and a second inner port fluidly coupled to a second outlet of the respective pair of outlets, each of the inner ports to receive the fluid from the associated outlet such that the fluid pressure of the inner port corresponds to the fluid pressure of the associated outlet, the fluid pressure of each of the inner ports being applied to the inner ends of the vanes associated with the inner ports to bias the vanes radially outward during rotation of said pumtping element.