| 摘要 |
1481658 Bearings BALZERS PATENT-UND BELEILGUNGS AG 5 Sept 1975 [27 Sept 1974] 36556/75 Heading F2A [Also in Divisions F1 and G3] A turbo vacuum pump comprises a stator and a rotor arranged in a cylindrical casing 1 having an exhaust port 3 and a suction port 2, and means for radially journalling and further means for axially journalling the rotor, which further means comprise an arrangement of permanent magnets 15 mounted on the rotor and generating a substantially radial magnetic field, and a coil 17 fixed relative to the casing and coaxial with the rotor, and dipping into the field of the permanent magnet arrangement. Current flowing in the coil exerts an axial force on the rotor, and is controlled by a sensor 18 which detects changes in the position of the rotor. The means for radially journalling the rotor comprise arrangements of permanent magnets 9, 12, opposite which ferromagnetic or permanent-magnetic sections 8, 11 of the rotor are positioned. Conical bearing bushes 20, 21 serve as emergency bearings. Means 19 for re-inforced damping of radial movement may be provided. The coil 17 and the stator 24 of a commutator-less driving electric motor may be combined into a structural group which can be dismantled from the pump casing without interference with the rotor or stator of the pump.
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