Vacuum pump and method of operating the same

摘要

A vacuum pump comprises a suction nipple valve including a cylinder, a piston slidably received therein and a movable valve closing member operatively connected to the piston. The vacuum pump further has a pressure medium conduit having a first end communicating with the cylinder; an inlet opening at a second end of the conduit for pressure medium to flow through the inlet opening to the piston; a control arrangement for closing and opening the inlet opening dependent upon run or standstill of the vacuum pump. In the closed state of the inlet opening an oil quantity is maintained above the inlet opening.