Mabuchi Motor Co., Ltd.

Kazumasa Saiga

Kazuo Okada

Keisuke Ebihara

Eiichi Sakuma

Yuji Kashiwazaki

A miniature motor including a motor case formed into a bottomed hollow cylindrical shape having a cross-sectional shape having two long sides consisting of two parallel lines (planar portions) and two short sides. An end bracket is fitted to an open end of the motor case. Permanent magnets are fixedly fitted to the cylindrical inside surface of the motor case. The inside surfaces of the permanent magnets, when assembled, form part of a cylindrical surface. An armature is rotatably supported in the motor case via bearings provided on the motor case and the end bracket. Recesses are provided on the inside of the parallel planar portions of the motor case and positioned in such a manner that a gap g.sub.1 between the inside surfaces of the recesses and the armature is related to a gap g.sub.2 between the inside surfaces of the permanent magnets and the armature by a relationship that g.sub.1 g.sub.2. A method is further proposed of making the motor in which the recesses are formed by ironing.

Miniature motor and method of making same

A miniature motor including a housing formed into a bottomed hollow cylindrical shape, on the inner circumferential surface of which a permanent magnet is fixedly fitted; A rotor is provided having an armature, a spark-quenching element and a commutator. An end bracket is provided having brushes fitted to the open end of the housing and making sliding contact with the commutator. Input terminals are electrically connected to the brushes; The rotor is rotatably supported by bearings provided on the housing and the end bracket, in which the spark-quenching element is formed by a laminated ceramic capacitor formed into a ring shape, having on the outer surface thereof the same number of electrodes as the number of poles of the armature; The electrostatic capacity of the capacitor is more than 1 .mu.F.

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Matsudo, Japan

Kazumasa Saiga