Sliding vane vacuum pump with an oil relief valve

摘要

A sliding vane vacuum pump includes a casing (10) having a cover which together define a cavity (12), a rotor and a vane slidably mounted to said rotor. The pump further includes an inlet passage (24) extending from the exterior of the pump to the cavity (12) and an outlet passage (20) extending from the cavity (12) to the exterior of the pump. The pump further includes an oil relief arrangement operable to vent lubricating oil to the exterior of the pump in the event of reverse rotation of the rotor and vane.