PERMANENT MAGNET TYPE ROTARY ELECTRIC MACHINE AND ELECTRIC POWER STEERING APPARATUS USING THE SAME

摘要

Not less than two regions different in magnetic circuit design are provided in a rotational axis direction of the rotor (30), the regions being different by changing a cross-sectional shape in the rotational axis direction in a cross-section perpendicular to a rotational shaft (10) of the rotor (30) having the permanent magnets (1) and the rotor core (2); the supplemental grooves (5) are provided in axial partial regions of each of the teeth (7) of the stator core (3); and the region in which the supplemental groove (5) is provided is each partial region for each region facing a region same in magnetic circuit design of the rotor (30). This enables to reduce cogging torque generated by variations on the rotor side.

主权项

1. A permanent magnet type rotary electric machine comprising:
a rotor having a plurality of magnetic poles composed of permanent magnets and a rotor core; and a stator including armature windings and a stator core which is provided with slots for incorporating said armature windings and has a plurality of teeth facing said rotor, each of said teeth of said stator core being provided with supplemental grooves at portions facing said rotor, wherein not less than two regions different in magnetic circuit design are provided in a rotational axis direction of said rotor, the regions being different by changing a cross-sectional shape in the rotational axis direction in a cross-section perpendicular to a rotational shaft of said rotor having said permanent magnets and said rotor core; the supplemental grooves are provided in axial partial regions of said tooth of said stator core; the region in which the supplemental groove is provided is each partial region for each region facing a same region in magnetic circuit design of the rotor; and an axial end face of the supplemental groove is located in an end face perpendicular to the rotational shaft between the regions different in magnetic circuit design of said rotor.