Abstract: A rotary electric motor is provided which comprises an annular first rotor, an annular stator disposed concentric with and radially outside the first rotor, and an annular second rotor disposed concentric with and radially outside the stator, the stator including a stator core made up of a plurality of stator pieces that are arranged in a circular array and electrically independently from each other, coils wound around the respective stator pieces, annular first and second brackets disposed on opposite axial ends of the stator core, a fastening device passing through holes of the first and second brackets and fixedly holding the stator core between the first and second brackets, and an induction current suppressing device suppressing an induction current that is produced in response to a variation of magnetic flux of each of the coils and flows through the fastening device.

Abstract: A multi-shaft, multi-layer motor has a stator coaxially disposed between inner and outer rotors which are driven independently by a compound current. For cooling stator coils, first through last branch coolant passages are arranged around the axis. The upstream ends of the first through last branch passages are arranged in sequence circumferentially along a distributing circumferential passage in a direction away from a common introduction port for introducing the coolant into the distributing circumferential passage, and the downstream ends of the first through last branch passages are distributed in sequence circumferentially along a collecting circumferential passage in a direction toward a common discharge port for discharging the coolant from the collecting circumferential passage.

Abstract: A multi-shaft, multi-layer motor has a stator coaxially disposed between inner and outer rotors which are driven independently by a compound current. For cooling stator coils, first through last branch coolant passages are arranged around the axis. The upstream ends of the first through last branch passages are arranged in sequence circumferentially along a distributing circumferential passage in a direction away from a common introduction port for introducing the coolant into the distributing circumferential passage, and the downstream ends of the first through last branch passages are distributed in sequence circumferentially along a collecting circumferential passage in a direction toward a common discharge port for discharging the coolant from the collecting circumferential passage.

Abstract: A rotary electric motor is provided which comprises an annular first rotor, an annular stator disposed concentric with and radially outside the first rotor, and an annular second rotor disposed concentric with and radially outside the stator, the stator including a stator core made up of a plurality of stator pieces that are arranged in a circular array and electrically independently from each other, coils wound around the respective stator pieces, annular first and second brackets disposed on opposite axial ends of the stator core, a fastening device passing through holes of the first and second brackets and fixedly holding the stator core between the first and second brackets, and an induction current suppressing device suppressing an induction current that is produced in response to a variation of magnetic flux of each of the coils and flows through the fastening device.