Patent ID: 6168391
Filing Date: 2001-01-02
Classification: F04C

Abstract:
An oil pump apparatus comprising: 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 including a body to provide a chamber, a first port, a second port, a third port, a valve member slidably disposed in the chamber, an urging member for urging the valve member and an urging member's chamber for disposing the urging member, the first port communicating between the discharge port and the chamber, the second port communicating between one of the suction ports and the chamber, and the third port communicating between the other suction ports and the chamber; a first land portion provided by the valve member for receiving the fluid pressure via the first port and controlling the opening and closing of the first port, the second port and the third port, wherein the axial length of the first land portion is smaller than that of an opening in the third port; and a second land portion provided on the valve member, which defines the urging member's chamber between the body and one side of said valve member, and having a passage which communicates between the urging member's chamber and at least one of said suction ports.