SCREW-TYPE VACUUM PUMP

摘要

A screw vacuum pump, in particular for compression against atmospheric pressure, comprises a pump housing defining a suction chamber. Two meshing screw rotors are arranged in the suction chamber. Further, an overpressure outlet provided, which comprises an overpressure opening in a side wall of the suction chamber. Further, an overpressure valve is arranged in the overpressure outlet. The width (b) of the overpressure opening in the longitudinal direction of the screw rotors is smaller than or equal to a tooth width (B) of the screw rotors.