Mitsuba Corporation

Ryuichi Takakusagi

Yoshichika Kawashima

Kenji Sakata

Tatsuyuki Saito

Toshiyuki Kimura

A windshield wiper motor includes a reduction mechanism unit and an electric motor. The electric motor includes a yoke formed in a bottomed cylindrical shape; four magnets arranged in a cylindrical shape on an inner surface of the yoke, an armature including a rotary shaft rotatably supported by the yoke, an armature core fixed to the rotary shaft and including any teeth of fourteen teeth, eighteen teeth, and twenty two teeth, a commutator being fixed to the rotary shaft and including a plurality of segments insulated from each other with the same number as the number of the teeth of the armature core, an armature coil being wound, and a plurality of connecting wires respectively connected to the segments arranged to face each other around the rotary shaft, and a first brush, a second brush, and a third brush coming into sliding contact with the segments of the commutator.

Electric motor and reduction motor

Disclosed is an electric motor including a yoke formed in a bottomed cylindrical shape; permanent magnets arranged on an inner peripheral surface of the yoke; an armature including a rotary shaft journalled on the yoke, an armature core formed with a plurality of teeth and fixed onto the rotary shaft, an armature coil wound around the teeth of the armature core, a commutator having a plurality of segments and being fixed onto the rotary shaft, and a connecting wire connecting two segments arranged to face each other back to back around the rotary shaft, the armature being surrounded by the permanent magnets and accommodated within the yoke; and a first brush, a second brush, and a third brush coming into sliding contact with the segments of the commutator of the armature.

Disclosed is a windshield wiper motor having a reduction mechanism unit and an electric motor. The electric motor of the windshield wiper motor includes a yoke formed in a bottomed cylindrical shape; permanent magnets arranged on an inner peripheral surface of the yoke; an armature including a rotary shaft journalled to the yoke, an armature core where a plurality of teeth are formed and fixed onto the rotary shaft, an armature coil wound around teeth of the armature core, a commutator having a plurality of segments and being fixed onto the rotary shaft, and a plurality of connecting wires connecting two segments arranged to face each other back to back around the rotary shaft, being surrounded by the permanent magnets and arranged within the yoke; and a first brush, a second brush, and a third brush coming into sliding contact with the segments of the commutator of the armature.

Disclosed is a motor in which a commutator () is provided with connecting wires which short-circuit equipotential segments; brushes () are constituted by a low-speed brush (), a high-speed brush (), and a common brush () used in common by the low-speed and high-speed brushes, and are juxtaposed along the circumferential direction. The circumferential brush width (W) of the high-speed brush is set to be smaller than the circumferential brush width (W) of the low-speed brush. The high-speed brush and the low-speed brush are formed so that simultaneous sliding contact with equipotential segments () can be avoided. Additionally, armature cores () are provided such that a plurality of teeth () is point-symmetrical about a rotary shaft () at equal intervals in the circumferential direction, and the teeth and slots () 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.

Growing community of inventors

Kiryu, Japan

Ryuichi Takakusagi