Patent ID: 7802973

Claim:
A vane pump comprising: a vane section operable to pressurize a working fluid; structure defining a suction port configured to deliver working fluid into the vane section, wherein the suction port is configured to conduct fluid along a suction port flow path; structure defining a delivery port configured to receive pressurized working fluid from the vane section; structure defining a return port configured to receive working fluid from the delivery port, wherein the return port is configured to conduct fluid along a return port flow path, and wherein the return port flow path is generally parallel to the suction port flow path; a throttle valve configured to receive working fluid from the return port and to accelerate the flow of the working fluid by a region of the throttle valve having a cross-sectional flow area less than a cross-sectional flow area of the return port; structure defining a mixing chamber configured to receive working fluid from a working fluid tank through the suction port and accelerated working fluid from the return port and the throttle valve and to mix those working fluids together before the mixed fluids enter the vane section; wherein working fluid flows through the suction port and accelerated working fluid from the return port through the throttle valve generally intersect; and wherein the accelerated working fluid from the return port is formed within the vicinity of the suction port.