Oil-superimposed discharge valve for rotating vacuum pumps

摘要

The invention concerns a discharge valve for rotating vacuum pumps. This implements three valve functions: the previous function of discharging gas or air, and pressure-dependent oil feed and draining as additional new functions. It consists of a valve chamber, a piston moving in this with valve seat in its bottom, a stopper, compression springs and support elements. In the wall of the valve chamber there is at least one aperture close to the bottom, and two apertures in the middle section. Of these two apertures, one is connected to the pump's suction chamber via an oil line. The outer wall of the piston has a ring groove, whose distance to the bottom edge of the piston is selected so that together with the piston stroke, it corresponds to the distance of the two apertures from the bottom of the valve chamber. The one compression spring is located between the stopper and a support element in the piston, while the other compression spring stretches from this support element to a support element near the upper edge of the valve chamber.