Patent ID: 7825552

Claim:
A variable reluctance electric machine comprising: a rotor having a plurality of salient poles, the salient poles defining axially extending cooling fluid channels; and a stator, the stator having: a stator core, two or more stator teeth extending radially from the stator core; and two or more electromagnetic windings, each electromagnetic winding winds around one of the stator teeth, wherein the stator has a cooling arrangement including at least one cooling region being defined between adjacent windings, the at least one cooling region comprising circumferentially skewed channels, wherein the salient poles and the cooling fluid channels are circumferentially skewed along at least a part of their length whereby in use the cooling fluid channels provide a flow of cooling fluid in a substantially axial direction through the electric machine to facilitate heat transfer and dissipation from the electromagnetic windings, and the at least one cooling region comprising skewed channels is adapted to receive cooling fluid flow in a generally radial direction from the rotor and to direct it generally axially to facilitate heat transfer and dissipation from the electromagnetic windings.