Permanent magnet-type rotary electric machine

A permanent magnet-type rotary electric machine comprising:

• a stator including a stator core extending annularly, a plurality of stator teeth protruding from the stator core toward a center of the stator core, a plurality of stator slots each provided between adjacent stator teeth of the plurality of stator teeth, a plurality of stator magnets each installed in a corresponding one of the plurality of stator slots, and a stator coil wound around each of the plurality of stator teeth;
• a first rotor including a plurality of first pole pieces arranged along a circumferential direction of the stator core with a space from the stator, the first rotor being disposed inside the stator core relative to the plurality of stator magnets;
• and
• a second rotor including a plurality of second pole pieces arranged along the circumferential direction of the stator core with a space from the first rotor and having a permanent magnet, the second rotor being disposed inside the stator core relative to the plurality of first pole pieces,
• wherein the stator coil is wound around each of the stator teeth as a concentrated winding,
• a relation NL=NS+NH is satisfied, where NS is a number of the stator slots, NL is a number of the first pole pieces of the first rotor, and NH is a number of the second pole pieces of the second rotor, and
• a first value of a winding factor multiplied by a speed increase/decrease when a proportion of a number of the plurality of stator slots to a number of poles of the plurality of second pole pieces of the second rotor is greater than 1.25 and less than 1.5, or greater than 1.5 and less than 3.0 is smaller than a second value of the winding factor multiplied by the speed increase/decrease ratio when NS/NH=1.5.