Brush and commutator motor having brush device using the same

摘要

A binded carbon brush includes a brush main portion formed mainly of carbon, and an electric conductor formed by a material, such as a copper powder, having an electric resistivity lower than that of the brush main portion and extending along a main current direction of the brush. In the cross section of the brush perpendicular to the main current direction, the diameter or the vertical and horizontal sizes of the conductor is so set as to be smaller than both the vertical and horizontal sizes of the brush main portion.