Denso Corporation

Hitachi Powdered Metals Co., Ltd.

Tris Inc.

Hirotake Hamamatsu

Chio Ishihara

Kazuo Asaka

Tsuyoshi Akao

Kohei Muramatsu

Youichi Murakami

Kenzo Kiyose

Yoichi Sakaura

Mitsuo Ikeda

Makoto Nishio

Shinya Nakagawa

Ryoichi Honbo

A method for producing a soft magnetic powdered core includes preparing a mixture of a soft magnetic powder and a resin powder, compacting the mixture into a predetermined shape so as to obtain a compact, and heating the compact. The resin powder has a median size of not more than 30 &#x3bc;m, a maximum particle size of not more than 100 &#x3bc;m, and a specific surface area of not less than 1.0 m/cm, and the additive amount thereof is 0.005 to 2 vol %.

Method for producing soft magnetic powdered core

A method for producing a soft magnetic powdered core comprises a mixing step for forming a raw powder by adding a thermoplastic resin powder to a soft magnetic powder and mixing them, a compacting step for forming a compact by compacting the raw powder into a predetermined shape, a melting and setting step for the resin in which the resin of the compact is melted by heating to at least the melting point of the thermoplastic resin and the melted resin is set by cooling to a room temperature, and a crystallizing step for the resin in which the set resin is heated to not less than the exothermic onset temperature and not more than the endothermic onset temperature, which are measured by DSC analysis of the thermoplastic resin, and is cooled to a room temperature.

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

Growing community of inventors

Kariya, Japan

Hirotake Hamamatsu