| 摘要 |
<p>A rotary hydraulic vane pump (12/78) includes a rotor (18) mounted within a housing (16), with a plurality of vanes (30) individually slidably disposed in corresponding slots (28) in the rotor periphery. A cam ring surrounds the rotor within the housing and has a radially inwardly facing vane track defining as least one arcuate fuel pressure cavity between the rotor (18) and the cam ring (38). A fuel inlet (48,54) in the housing includes a primary inlet port (44,174) opening into the cavity (42) at the leading circumferential edge of the cavity with respect to the direction of rotation of the rotor (18) within the housing. A pump outlet includes an outlet port that opens into the cavity (42) adjacent to the trailing circumferential edge of the cavity. A secondary inlet port (64) opens into the cavity circumferentially between the primary inlet port (44) and the outlet port, and is directly connected to the pump outlet port (60) such that fluid at outlet pressure is available at the secondary inlet port. A pressurization valve (114), having a predetermined threshold pressure for permitting flow of fluid therethrough, is connected between the pump outlet (60) and the primary pump inlet port (44).</p> |
