PURPOSE: To always press a brush on a commutator by a uniform pressing force even if the brush is worn by pressing the brush inclined at the intermediate part of a leaf spring in which both ends are formed in coiled parts, on the commutator.

CONSTITUTION: A brush holder 44 is secured to the oblique face 42A of the upper end of the raised part 42 of an insulator plate 28, and a brush 48 is held between the holder 44 and the oblique face 42A. A leaf spring 62 for applying a pressing force to the brush 48 is formed at both ends in coiled parts 62A, and brought at the intermediate part into contact with the brush 48, to press the brush 48 to a commutator 38 by the energizing forces of the coiled parts 62A. Here, the coiled part 62A of the spring 62 is drawn to a cutout 58 to be wound. When the brush 48 is worn by the friction with the commutator 38, the coiled part is wound on a holding part to always continuously press the brush on the commutator by a uniform force. Thus, it can prevent the pressing force of the brush from varying due to fluctuation.