| 摘要 |
1302414 Electric motors; core constructions LICENTIA PATENT-VERWALTUNGSGmbH 15 Jan 1970 [15 Jan 1969] 2124/70 Heading H2A In a hysteresis motor having a slotted stator, the effects of slot harmonics on the air gap flux density are reduced by mounting in the air gap, and spaced from the stator, a body of soft magnetic material. The body may comprise a single ring of magnetic material or a plurality of electrically insulated concentric rings of magnetic material, or a plurality of wafers, each bridging the gap between two adjacent stator teeth. The discoidal motor shown includes an annular strip core 1 carrying polepieces 2 and a three phase ring type winding 3. This assembly is embedded in synthetic resin 5 and surrounded by a conductive screening can 4 to reduce the core leakage flux. Three soft magnetic rings are mounted in the planar air gap between the stator and the hysteresis rotor, 6. The motor is adapted to drive a gas centrifuge at over 60,000 r.p.m. and the rotor may be formed integrally with the wall of the centrifuge vessel. The dimensions of the wafers, where these are used, are given in terms of slot width, the saturation density of the soft magnetic material and the peak air gap flux density. |
