Hydromechanical protection device for pumps

摘要

The invention relates in particular to an oil-immersed rotary vane vacuum pump with a valve which is situated in the intake space and shuts off the active pump part from the recipient or tank when the pump is stationary. The aim is to ensure oil-free, reliable sealing off of the evacuated apparatus from the active pump part when the pump comes to a halt suddenly. The object is to develop an oil-free protection valve which closes vacuum-tightly and is actuated without a separately driven pressure medium source when the pump is stationary. The object is achieved by the fact that a centrifugal mechanism is provided in the region of the driving coupling and its centrifugal weights move a sealed-off control piston situated in the drive shaft axially counter to a helical spring provided in the neck of the hollow shaft of the coupling, the control piston being connected to a nonreturn valve and to a ventilation valve which actuates a protection device.