A Stator and a Rotor for an Electric Motor

摘要

The rotor 4 comprises a hub 73, a plurality of rotor segments 72, and a plurality of permanent magnets 56. The segments are arranged around the hub in a ring, with the permanent magnets disposed between the segments, radially outwardly facing exposed surface of each magnet being spaced radially inwardly from an outer cylindrical profile forming retaining lips defined by the segments. Grooves 70 increase the surface area available for heat transfer. Coolant air is directed over the inner surface of the hub 73 and then returns along the outer surface of the rotor via radial grooves in the end flange onits rotor facing surface (fig 14-16 not shown). The stator 2 comprises a plurality of stator coils 12 and a support 30 for holding the coils around a rotor of the motor. A cylindrical sleeve 16 of fibre- reinforced material e.g. carbon fibres wound in opposed spirals is mounted by interference fitting 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. Housing 35 defines coolant passages 33 to return coolant supplied to channels along which the windings extend.