Patent ID: 6634865
Filing Date: 2003-10-21
Classification: F01C,F04C

Abstract:
A vane pump comprising:a) a pump housing having a cylindrical interior chamber defining a central axis through which a vertical centerline and a horizontal centerline extend; b) a cam member disposed within the interior chamber of the pump housing and having a bore extending therethrough and defining a circumferential surface of a pumping cavity, the circumferential surface of the pumping cavity including a discharge arc segment of about 150 degrees, an inlet arc segment of about 150 degrees and seal arc segments of about 30 degrees separating the inlet arc segment and the discharge arc segment from one another; c) a cylindrical rotor member mounted for rotational movement within the bore of the cam member about an axis aligned with the central axis of the interior chamber, the rotor member having a central body portion which includes a plurality of circumferentially spaced apart radially extending vans slots formed therein, each vane slot supporting a corresponding vane element mounted for radial movement therein, each vane element having a radially outer tip surface adapted for slideably engaging the circumferential surface of the pumping cavity and a radially inner undervane portion within each vane slot; and d) a chamber defined within the housing and positioned for fluid communication with the undervane portion of each vane element and providing a desired pressure thereto, the chamber being in fluid communication with a first pressure source and a second pressure source, wherein the first pressure source is associated with the discharge arc segment of the pumping cavity, and the second pressure source is associated with the inlet arc segment of the pumping cavity.