Abstract: A high speed rotating electromagnetic motor/generator includes a rotor having a core of magnetic material, a layer of permanent magnet, a retainer ring and side walls of non-magnetic material. A stator is provided by magnetic steel laminations and winding slots. A case includes a cylindrical inner casing, a cylindrical outer casing and end caps which carry the machine bearings. The permanent magnets within the rotating part may be made of neodymium-boron-iron and produce a high flux density pole rotor. The motor/generator can be operated as a brushless direct current or synchronous alternating current machine. Efficient means of cooling is provided by helical channels, which carry a liquid coolant, and are formed in the casing.

Abstract: A rotating part for a high speed synchronous generator comprises a core of magnetic material, side walls of nonmagnetic material, and an outer circumferential portion. The outer circumferential portion is provided on its outside with an inner layer, an inner retaining ring, an outer layer and an outer retaining ring. The inner and outer layers are made up of magnetic and nonmagnetic portions. The retaining rings are of magnetic material. The greater strength and lighten weight of the nonmagnetic portions reduces the centrifugal forces on the magnetic portions. In an alternative embodiment, the outer circumferential portion comprises a number of layers comprising alternate portions of magnetic and nonmagnetic material, retained by rings of magnetic material. The nonmagnetic portions support the magnetic material, and prevent it from damage through centrifugal force.