| 摘要 |
PURPOSE:To reduce the abrasion of a brush by vibration and also, improve cooling effect by supporting the support plate of a brush holder with an annular insulating board provided at the partition plate of a collector cover, and cooling the brush holder and a brush by cooling wind circulating axially in the ventilation hole provided in the insulating board. CONSTITUTION:The periphery of an annular insulating board 2 is fixed with a bolt 13A to each partition plate 9B inside a collector cover 1. And, the outside periphery of an annular brush holder 3 is abutted against the inside periphery of this insulating board 2, and a brush holder 4 is fixed to the insulating board 2 with a bolt 13B together with a brush holder plate 3. Moreover, in the brush holder support plate 3, a ventilation hole is made in the position between each brush holder 4 and the next. Hereby, the abrasion is reduced by suppressing the vibration of the brush 4, and also the cooling effect at and around the brush 4 can be improved by the cooling wind circulating in axial direction. |
