Patent ID: 6638010
Filing Date: 2003-10-28
Classification: F04D

Abstract:
A gas friction pump, comprising a housing (1) having a suction opening (2) and a gas outlet opening (3); rotor (12) and stator (14) components arranged in the housing (1) for delivery of gases and for obtaining a pressure ratio; a rotor shaft (4) located in the housing for supporting the rotor components (12); and an additional, at least one-stage, concave pump unit (20, 30, 40) provided at a side of the suction opening (2) and having a gas delivery structure, the additional pump unit (20, 30, 40) being so formed that gas delivery takes place in a radial direction, and rotor components (21, 31, 41) of the additional pump unit (20, 30, 40) being supported on the rotor shaft (4) of the gas friction pump.