Patent ID: 6241490
Filing Date: 2001-06-05
Classification: F04C

Abstract:
A vacuum pump, comprising:a pump housing (1) having an inlet (2) and an outlet (3);a main rotor (4) having a first bell-shaped lobe (6a) and a second bell-shaped lobe (6b), said main rotor (4) being positioned inside said housing (1) such that said first and second bell shaped lobes (6a, 6b) define a working chamber (8) with said pump housing;a rotor drive element (13) contacting said main rotor for rotating said main rotor (4), said rotor drive element being positioned radially inward from said main rotor and opposite to a stator element (12) positioned radially inward from said rotor drive element (13);a control rotor (5), said control rotor (5) being provided with at least one recess (7) for accommodating at least one of said first and second lobes (6a, 6b); andwherein upon said main rotor being driven so as to rotate, fluid is pumped from said inlet (2) through said working chamber (8) and to said outlet (3).