Mabuchi Motor Co., Ltd.

Kazuo Okada

Keisuke Ebihara

Kunio Hiromasa

Hitoshi Fujiwara

Kazumasa Saiga

Etuo Mayumi

A miniature motor comprising a case made of a metallic material, formed into a bottom hollow tubular shape and having a permanent magnet fixedly fitted to the inner circumferential surface thereof, a rotor consisting of an armature facing the permanent magnet and a commutator, and a case cover engaged with an open end of the case and comprising brushes making sliding contact with the commutator and input terminals electrically connected to the brushes; the rotor being rotatably supported by bearings provided on the bottom of the case and the case cover, and a printed circuit board having a control element and a soundproofing plate made of a soundproofing material being provided outside the case cover, in which the soundproofing plate is formed into a cross shape when projected on a plane orthogonally intersecting the axial line of the rotor.

Miniature motor

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 comprising a case formed into a bottomed hollow tubular shape and having permanent magnets fixedly fitted to the inner circumferential surface thereof, a rotor consisting of an armature and a commutator, and a case cover engaged with an open end of the case and having brushes making sliding contact with the commutator, and input terminals electrically connected to the brushes, in which fixing ribs are provided on the inner circumferential surface of the case, extending along the axial direction of the case; the edges of the permanent magnets formed into an arc-segment cross-sectional shape being caused to make contact with the side edges of the fixing ribs to fixedly fit the permanent magnets to the inner circumferential surface of the case; projections formed integrally with the permanent magnets along the edges of the permanent magnets are provided facing the surface of the fixing ribs.

A miniature motor having installed motor components in a housing made of a metallic material and formed into a bottomed, hollow cylindrical shape with an opening at one end thereof; a cover made of a metallic material and formed into a plate shape being fixedly fitted to the opening, in which a plurality of minute ridges are provided on the outside circumferential surface of the cover, and the outside dimensions of the cover are made equal to, or slightly larger than, the inside dimensions of the housing opening so as to ensure a firm press-fit between the cover and the housing opening, thereby maintaining electrical contact between both.

Growing community of inventors

Chiba, Japan

Kazuo Okada