BRUSH

PROBLEM TO BE SOLVED: To see that the brush does not cause abnormal heating and abnormal abrasion, while achieving the full-fact touch with a commutator in its early stages, by forming an inclined groove slant in the rotational direction of a commutator, at the end face of a flange. SOLUTION: For a brush 10, a plurality of inclined grooves 10b slant in the rotational direction of a commutator are made, and inclined ribs 10c are made, and it is electrically connected by being retained by a brush holder 8 and one end of a lead wire 11 being embedded. Moreover, the brush 10 is pressed against a commutator piece 7 with fixed pressure by the action of the push spring 12 within the brush holder 9. Then, when the commutator 6 rotates, the brush 10 is worn away gradually, accompanying the rotation of the commutator 6, but sine an inclined groove 10b is made at the brush 10, it contacts with the armature, covering the wide region in axial direction of the commutator piece 7 at the surface of the ccmmutator 6 soon after start of rotation. Hereby, it is worn away equally from the early stage of the rotation, and favorable commutation state can be obtained in its early stages.