Abstract: A stator and a rotor suitable for use in an electric motor or generator. The stator comprises a plurality of stator cons and a support for holding the coils around a rotor of the motor. A cylindrical sleeve is mounted radially inwardly on the support to form a barrier in use between cooling fluid passing over the coils and a rotor located within the stator. The rotor comprises a hub, a plurality of rotor segments, and a plurality of permanent magnets. The segments are arranged around the hub in a ring, with the permanent magnets disposed between the segments. A radially outwardly facing exposed surface of each magnet is spaced radially inwardly from an outer cylindrical profile defined by the segments.

Abstract: A hub for a rotor of a permanent magnet motor comprises fluid conduits which extend radially outwardly to a region radially beneath each magnet of the motor and then radially inwardly. A rotor of a permanent magnet motor is also provided which includes a hub body having a plurality of lugs on an outer circumferential surface of the hub body, each lug substantially consisting of a tapered base portion and a head portion. The maximum width of the base portion of each lug in the circumferential direction substantially corresponds to the circumferential distance between the adjacent permanent magnets. Furthermore, a rotor of a permanent magnet motor comprises rotor segments having axially extending grooves defined in a radially extending sidewall of each rotor segment.

Abstract: A rotor suitable for use in an electric motor or generator. The rotor comprises a hub having a central axis, a plurality of rotor segments and permanent magnets, and an assembly for retaining the segments on the hub. The segments are arranged around the hub to define at least two rings, which are adjacent to each other in the axial direction with a permanent magnet disposed between each of the segments in each ring. The assembly includes a plurality of rods which extend in an axial direction to retain the rotor segments. An intermediate plate is located between each ring of segments through which the rods pass, wherein the intermediate plates and the outer circumferential surface of the hub engage with each other in such a way as to allow the intermediate plates to move axially along the hub.