Abstract: A turbomolecular vacuum pump has a housing, a vertically oriented hollow pump rotor situated in the housing, and a vertically upwardly oriented stub shaft affixed to the housing and extending into the hollow pump rotor. The pump rotor is supported on the stub shaft by a magnetic axial bearing and at least one magnetic radial bearing, all disposed in the space surrounded by the hollow pump rotor.

Abstract: This invention relates to magnetic bearings and particularly to active magnetic bearings having a very low "friction couple". In accordance with the invention the active magnetic bearing is of the type which has a stator formed by an electromagnetic circuit having at least one pair of north and south poles, and wherein said electromagnetic circuit of said stator includes at least one electromagnet of U-shaped section. The arms of said U form north pole and south poles respectively and the electromagnet is so arranged that the plane of symmetry which separates the north pole from the south pole lies perpendicularly to the axis of rotation of the magnetic bearing.