Pump construction

Abstract

A pump, particularly a turbo vacuum pump, comprises a housing having an intake and an exhaust spaced from the intake. The respective ends of the housing are provided with bearing bushes which extend in respective opposite directions and support a pump rotor in a manner to permit it to have some axial and radial play. A first magnetic system acts on the rotor and stabilizes the rotor axially in respect to the bearings and a second magnetic system acts on the rotor and stabilizes the rotor radially in respect to the bearings. The second magnetic system includes at least one permanent magnet which is fixed to the casing and faces either soft iron or permanent magnet portions provided on the rotor. An electromotor is mounted within the casing and the coil of the electrodynamic system and the stator of the drive motor are assembled to a subassembly which can be mounted or dismounted from the pump casing in a simple manner without interfering with the rotor or the stator. The magnetic centering system includes a permanent magnet which produces a magnetic field of an electrodynamic system which is secured to the inner surface of a pot-shape yoke having a central core pin. The motor is of known construction but without a commutator and it is equipped with permanent magnets and designed as an outside rotor which is mechanically connected to the pot-shape yoke and which carries permanent magnets on its inside.