Abstract: A commutator has such a construction that a flange having an outside diameter larger than the outside diameter of a cylindrical body is provided integrally with the cylindrical body in the vicinity of one end of the cylindrical body; guide grooves formed in a circular arc shape in cross section are provided on the flange at the boundary of the flange to the cylindrical body; engaging pieces passing through the guide grooves are provided on one end of a commutator segment; and engaging pieces are caused to deform plastically to fixedly fit the engaging pieces to the flange.

Abstract: A bearing device for miniature motors having a cylindrically-shaped bearing support formed by pressing an end face of a metallic motor case, and a bearing press-fitted into the bearing support to rotatably support a motor shaft, characterized in that a pressed groove is formed on the outer circumferential surface of the bearing support by pressing the outer circumferential surface is disclosed. A method of making a bearing device for miniature motor in which the clearance between the bearing and the motor shaft is set by pressing the outer circumferential surface of the bearing support using a pressing jig in a state where the motor shaft is inserted into the bearing is disclosed.

Abstract: A miniature motor having a cup-shaped cylindrical motor case fitted with a plurality of motor mounting holes and a bearing on the closed end face thereof, and a rotor rotatably supported at one end of the shaft thereof in the motor case by the bearing provided on the closed end face of the motor case, a motor mounting portion is provided around motor mounting holes in a raised fashion from the closed end of the motor case so that the surface of the motor mounting portion intersects with the shaft at substantially 90 degrees. Also, a miniature motor in which the surface of the motor mounting portion is ground and polished is disclosed.

Abstract: A bearing device for small rotary machinery having such a construction that a cylindrical bearing having therein a ball bearing is housed in a housing, made of a synthetic resin, for rotatably holding a rotating shaft having a rotor, in which a cap having a flange portion is interposed between the housing and the bearing to stably retain the rotating shaft.

Abstract: Brushgear having brushes, each comprising a terminal and a brush arm, both made of electrically conductive metal strips and joined together into one piece, the brushes being held in position on a side plate of a motor case, made of a synthetic resin, by being inserted into terminal holes provided on the motor case side plate. The terminal and brush arm of each brush are made of different metal strips and a terminal strip of the terminal and a brush strip of the brush arm are mechanically joined together into one piece by folding joining members provided integrally with the terminal strip in such a manner as to wrap around an end of the brush strip provided on the brush arm. The joined portion of the terminal and brush strips are inserted into the terminal hole to hold the brush in position on the motor case side plate.

Abstract: The disclosure relates to a composition suitable for use in mechanical power transmission devices. It has as its principal component a hydrocarbon oil which has from 19 to 30 carbon atoms, inclusive, and three six-membered carbocyclic rings and consists of a mixture of compounds having the following formula: ##STR1## wherein R.sup.1 is a divalent straight or branched chain radical C.sub.y H.sub.2y where y is an integer of 1 through 3; R.sup.2 is a straight chain radical C.sub.z H.sub.2z where z is an integer of 1 through 3; R.sup.3, R.sup.4, and R.sup.