Patent ID: 7207785
Filing Date: 2007-04-24
Classification: F01C,F04C

Abstract:
1. A vane pump comprising: a) a pump housing having an interior chamber that defines a central axis through which a vertical centerline and a horizontal centerline extend; b) a cam member mounted within the interior chamber of the pump housing and having a bore extending axially therethrough and defining a circumferential surface of a pumping cavity, the pumping cavity including a discharge arc region, an inlet arc region and seal arc regions separating the inlet arc region and the discharge arc region from one another; and c) a substantially cylindrical rotor member mounted for rotational movement within the bore of the cam member about the central axis of the interior chamber, the rotor member having a central body portion with first and second axially opposed end surfaces and a plurality of circumferentially spaced apart radially extending vane 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, the first end surface of the body portion having a circumferential recess formed in a radially outer portion thereof so as to create a leak path for communicating fluid from the discharge arc region to the inlet arc region when the cam member is in a start-up position and an undervane portion of a vane element is positioned radially outward of a radially inner edge of the recess formed in the first end surface when such vane is positioned in the seal arc region of the pumping cavity.