Patent ID: 8264120

Claim:
A permanent magnet-less synchronous system comprising: a stator that generates a magnetic revolving field when sourced by an alternating current; and an uncluttered rotor disposed within the magnetic revolving field and spaced apart from the stator to form an air gap relative to an axis of rotation; where the uncluttered rotor comprises: a plurality of rotor pole stacks having an inner periphery biased by a single polarity of a north-pole field and a south-pole field, respectively, and an outer periphery biased by an alternating polarity; and a stationary excitation core disposed within and circumferentially separated from the plurality of rotor pole stacks, the stationary excitation core comprising a plurality of recessed ring-shaped spaces for receiving a plurality of excitation conductors, the recessed ring-shaped spaces being disposed adjacent to each other and about an axis of rotation of the uncluttered rotor; and where each of the inner peripheries of the rotor pole stacks biased by the single polarity are spaced apart by a spacer ring having an unbiased inner periphery.