Patent ID: 6663357
Filing Date: 2003-12-16
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 mounted 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, an inlet arc segment and seal arc segments separating the inlet arc segment and the discharge arc segments from one another; c) a 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 having 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; and d) means associated with the first end surface of the rotor member for communicating a high pressure fluid from a discharge arc region to an inlet arc region so as to prevent pump start-up, the fluid communication occurring when the tip surface of a vane element has worn a predetermined amount with respect to the undervane portion of such vane element.