Vacuum pump for under pressure power brake of motor vehicle, has impeller's front side and inner wall aligned within section plane and parallel to each other at operating temperature, where plane holds rotation axis of rotor

摘要

The vacuum pump has a rotor (13) rotating around a rotation axis (A) in a housing (11), and an impeller (21) guided in the rotor and cooperated with an inner wall (19) of the housing. The impeller is made of fiber reinforced plastic and lies against to an end with a front side (23) on an inner wall (19) of the housing. The front side of the impeller and the inner wall of the housing are aligned within a section plane and parallel or nearly parallel to each other at operating temperature of pump, which is higher than room temperature, where the plane holds the rotation axis of the rotor.