摘要 |
This invention relates to an oil pump apparatus which comprises an oil pump housing, a rotor rotatably located in the oil pump housing, the rotor forming a first set of pockets having a capacity increasing toward a rotating direction of the rotor and a second set of pockets having a capacity decreasing toward the rotating direction of the rotor, a plurality of suction ports connected with the first set of pockets, each of the suction ports being isolated from other adjacent suction ports, a discharge port connected with the second set of the pockets, and a control valve which includes a valve member, an urging member for urging the valve member and an urging member's chamber for disposing the urging member, the control valve being operatively positioned to control fluid flow through the plurality of the suction ports and the discharge port, and the control valve is operatively connected to select between a first condition in which the control valve connects with the suction ports and a second condition in which the control valve connects the discharge port with one of the suction ports and cuts off the other suction ports wherein the urging member's chamber is always communicated with one of the suction ports.
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