Brushless DC motor with rare-earth magnet rotor and segmented stator

Claim 1

A segmented multiphase stator in a motor having a permanent magnet rotor, each segment being comprised of a comb-like arcuate core having inwardly extending teeth over its entire arcuate length, and a support structure across the back of said core over less than its entire arcuate length to leave a portion of said core at each end thereof with teeth extending therefrom to provide a plurality of slots through which phase windings may be wound over the unsupported back of said core, said multiphase stator having each of successive phase windings started in successive slots between teeth in a symmetrical repetitive sequential order over the full length of said core, with each phase winding crossing over a plurality of teeth equal to the number of teeth at each end extending from said unsupported back of said core, and turns of successive phase windings wound in slots at each end of said core with one winding in each slot being completed over the unsupported back thereof, whereby teeth at each unsupported back of said core is provided with flux from successive phase windings equal to flux through teeth in the central supported portion of said comb-like core, thereby to complete the symmetry to the ends for a stator having the same number of phase windings for all teeth of said comb-like core for a more uniform field strength at the pole faces of the teeth at the ends thereof.