Patent ID: 6952069

Claim:
An electric rotating machine, comprising: an inner rotor including a plurality of permanent magnets circumferentially arranged; an outer rotor including a plurality of permanent magnets circumferentially arranged, the inner rotor and the outer rotor being coaxially disposed and driven by a compound current; a stator disposed between the inner rotor and the outer rotor, the stator including a stator core and a coil to which the compound current is applied, the stator core including a plurality of circumferentially arranged stator pieces on each of which the coil is wound, the stator pieces having a same shape and being formed by plates laminated in axial alignment with each other, each of the stator pieces including an inner yoke disposed radially inside, an outer yoke disposed radially outside and a coil area defined between the inner and outer yokes in which the coil is disposed, the stator pieces adjacent to one another including a first air gap circumferentially formed between the adjacent outer yokes thereof, a second air gap circumferentially formed between the adjacent inner yokes thereof and mutual contact portions circumferentially contacted at the inner yokes thereof; and wherein a contact portion comprises two contact regions disposed on the side of the inner rotor and on the side of the outer rotor, respectively, the second air gap being disposed between the two contact regions.