Pre-pressurization pump liner for vane pump

摘要

A vane liner (100) for use in a vane pump (90) has a vane liner body defining an inner bore for providing a cam surface in a vane pump. The cam surface has a suction opening (102) formed through the body at one circumferential extent, and a discharge opening (104) through the body at a distinct circumferential extent. A pre-pressurization opening (106) extends through the body at a location upstream of an upstream end of the discharge opening, but spaced by at least 90 degrees from a downstream end of the suction opening. A vane pump (90) incorporating the above-discussed liner is also claimed. Further, a vane pump (90) is also disclosed and claimed having the spacing from the downstream end of the suction opening (102) at least X degrees wherein X equals 360 divided by N, N being the number of vanes in the vane pump.