Abstract: A rotary vane pump includes a shaft of uniform diameter over at least the portion of its length passing through a cavity in a liner member which is eccentric to the shaft and a pair of end bearings defining opposite end faces of the cavity. Vanes extend from the shaft into contact with the eccentric cavity and define pumping pockets which expand and contract as the shaft rotates. The rotating shaft is mounted substantially tangent to the cavity in the liner and is journal mounted in such end bearings which seal opposite ends of the pumping pockets. The vanes are positioned axially of the shaft by means of a groove formed in one end face of the liner and corresponding tabs which project radially from each of the vanes. Alternatively, the groove may be formed by providing a separate wafer adjacent one end of the pump liner having an internal bore of a greater diameter than the internal diameter of the liner.