Abstract: A rotary electric machine comprises a rotating shaft rotatably supported by bearings, a rotor attached integrally with the shaft and a stator facing the rotor. The stator includes a plurality of coils arranged substantially in a circular form in a rotating direction of the shaft. The rotor includes a circular-disc rotor yoke made of a ferromagnetic material, such as iron. Depressed and raised portions on a surface of the rotor yoke facing the stator, except for the center portion, are arranged in a circumferential direction of the rotor yoke. N-pole and S-pole magnets are alternately arranged in the depressed portions. Therefore, in addition to torque generated by the magnets, reluctance torque is generated between the raised portions on the rotor yoke side and the teeth on the stator side, thus making it possible to increase the range of rotation speeds of the motor.

Abstract: A rotary electric machine comprises a rotating shaft 7 rotatably supported by bearings 2, 3, a rotor 23 attached integrally with the rotating shaft 7, and a stator 5 arranged facing the rotor 23. The stator 5 includes a plurality of coils arranged substantially in a circular (annular) form in a rotating direction of the rotating shaft 7. The rotor 23 includes a circular-disc rotor yoke 26 made of a ferromagnetic material, such as iron. Depressed portions and raised portions 28 on a surface of the rotor yoke 26 facing the stator 5, except for the center portion, are arranged in a circumferential direction of the rotor yoke 26. N-pole magnets 29 and S-pole magnets 30 are alternately arranged in the depressed portions 27. Therefore, in addition to torque generated by the magnets 29, 30, reluctance torque is generated between the raised portions 28 on the rotor yoke side 26 and the teeth on the stator side 25, thus making it possible to increase the range of rotation speeds of the motor.