Rotor having magnets with enclosing shells

A rotatable assembly for a dynamo-electric machine having means for reducing release of magnet material particles from said assembly, comprising:

• a flux ring, for providing a medium of distribution or magnet flux;
• a plurality of magnet assemblies disposed about the outer circumference of said flux ring, each said assembly including a generally bar-shaped body of permanently magnetizable material, a shell at least partially surrounding said body, said shell being disposed and located so as to reduce release of particles shed from the outer surface portion of said body surrounded by said shell, and means attaching said shell to said body;
• and
• means fastening said plurality of magnet assemblies to said flux ring so that said magnet assemblies are situated adjacent to each other and so that the outer surfaces of said magnet assemblies form the curved surface of a cylinder, said fastening means comprising a plurality of locking tabs formed as an integral part of said flux ring, said tabs being disposed and located so as to be in gripping engagement with confronting parts of said magnet assemblies and so that said magnet assemblies are at least in part retained against displacement from their respective positions around said flux ring.