Patent ID: 6422845
Filing Date: 2002-07-23
Classification: F01C

Abstract:
A sliding vane hydraulic pump comprising a housing having an undervane pressure chamber, a fluid pumping rotor operatively mounted in said housing for pumping hydraulic fluid supplied to an input leading into said housing to an output therein, a cam ring secured in said housing having an internal cam surface facing said rotor, said rotor having a plurality of arcuately spaced and radially extending vane slots therein, a sliding vane operatively mounted in each said slots and having an outer tip for sliding contact with said internal cam surface, said vanes having interior end surfaces cooperating with said slots to define undervane fluid passages adapted to be pressurized with hydraulic fluid that exerts a radial outward force on said vanes for effecting the operative engagement of the tips of said vanes with said cam surface, and laterally spaced pressure and thrust plates operatively mounted at radially fixed positions in said housing adjacent to opposite sides of said rotor to define pressure balancing side pockets for said rotor interconnected by said undervane fluid passages, each of said plates having at least one intake slot for feeding fluid into the vanes of said rotor and at least one fluid discharge slot formed therein rotationally downstream with respect to said intake slot, said pressure plate having a first passage therein leading from said discharge slot therein into said undervane pressure chamber and outboard of said pressure plate and a second passage therein radially inward of said first passage leading from said undervane pressure chamber into said side pockets of said rotor for the simultaneous pressurization of all of said undervane passages.