Denso Corporation

Tris Inc.

Ryoichi Honbo

Youichi Murakami

Masami Niimi

Yasuyuki Wakahara

Toshihiko Muramatsu

Kyoji Inukai

Kenzo Kiyose

Yoichi Sakaura

Mitsuo Ikeda

Takayoshi Otani

Yukio Inuzuka

Makoto Nishio

Masashi Miyamoto

Hirotake Hamamatsu

Shinya Nakagawa

Hirotada Kanagawa

Yukinobu Isoda

Masakiyo Shimada

A motor includes a rotor, a commutator, a brush, and a bias member. The commutator has a rectifying surface. The commutator rectifies an electric current supplied to the rotor through the rectifying surface. The rotor is rotated by being supplied with the electric current. The brush makes contact with the commutator via the rectifying surface. The rotor is supplied with the electric current through the brush. The brush starts making contact with the commutator on an entry side of the brush as the rotor and the commutator rotate with respect to the brush along a rotative direction and the commutator intermittently makes contact with the brush. The bias member biases the brush toward the entry side.

Commutator motor with brush biased toward initial contact side

In a commutator of a rotary electric machine, each of commutator segments has a low-resistive layer made of a low-resistive material and a high-resistive layer made of a high-resistive material having a specific resistance higher than that of the low-resistive material. The low-resistive material contains a carbonic material and a binder. The high-resistive material contains a carbonic material, a binder and an inorganic substance such as boron nitride. A mixing ratio of the inorganic material to the high-resistive material is more than 20 wt %. Alternatively, a brush, which makes contact with the commutator segments, can have the high-resistive layer and the low-resistive layer.

Brush, commutator, and commutator device

A copper-zinc alloy powder of which zinc content is from 10 to 50 wt % and of which mean particle diameter is from 15 &#x3bc;m or under is added to a Pb-less brush body comprising graphite, copper and a metal sulfide solid lubricant of a copper-graphite brush.

Copper-graphite brush

Growing community of inventors

Obu, Japan

Ryoichi Honbo