ELECTRIC MOTOR AND REDUCTION MOTOR

摘要

Disclosed is a motor in which a commutator (10) is provided with connecting wires which short-circuit equipotential segments; brushes (21) are constituted by a low-speed brush (21a), a high-speed brush (21b), and a common brush (2 1 c) used in common by the low-speed and high-speed brushes, and are juxtaposed along the circumferential direction. The circumferential brush width (W2) of the high-speed brush is set to be smaller than the circumferential brush width (W1) of the low-speed brush. The high-speed brush and the low-speed brush are formed so that simultaneous sliding contact with equipotential segments (15) can be avoided. Additionally, armature cores (8) are provided such that a plurality of teeth (12) is point-symmetrical about a rotary shaft (3) at equal intervals in the circumferential direction, and the teeth and slots (13) are formed so as to exist alternately at intervals of 90 degrees in the circumferential direction. By virtue of the above configuration, vibration and noise can be reduced while achieving miniaturization and high performance of a motor.