Doubly salient reluctance machines

Claim 1

A reluctance machine comprising: a stator having a core made from a highly permeable magnetic material; and a rotor, freely rotatable to be drawn into a position of alignment with the stator to minimize the reluctance at any point in time, both the stator and said rotor being constructed to cause changes in the reluctance of the magnetic circuit as the relative position of said rotor and said stator changes during operation of the machine, the stator carrying conductors arranged and terminated to allow currents to flow around a plurality of loops, the conductor loops capable of being energized from a multiphase current supply such that they may be sequentially energized for displacement of said rotor between successive positions of minimum reluctance, each of which loops has at least a pair of portions in which current flows in opposite directions with respect to that direction which is normal to the direction of movement of the rotor to form temporary magnetic poles within the stator, said magnetic poles being arranged in regularly spaced opposed pairs of poles, and wherein, for each loop, each portion of the loop carrying current in one direction is separated from each portion of the loop carrying current in the opposite direction by a peripheral distance equal to that separating adjacent magnetic poles of opposite sign.