摘要 |
A rotor comprising a rotor shaft and a rotor core on the shaft, the core being cylindrical. A number of arcuate permanent magnets are positioned at angularly spaced positions on the outer periphery of the core, and a tubular metal sleeve is positioned around the magnets. The sleeve extends beyond the axially outer ends of the magnets and the sleeve has end portions which extend radially inwardly and overlie the ends of said magnets. The sleeve has residual tension which produces a radially inwardly directed force on the magnets, and the end portions are spun or turned over and produce a force on the ends of the magnets. |