| 摘要 |
PURPOSE: To provide an inexpensive brush device which can protect a commutator motor with high reliability against the abnormal temperature increase of a brush owing to an abnormal spark generated between a commutator and the brush. CONSTITUTION: In a brush device 41 which is provided with a brush 44 energized by spring 46 to be elastically pressed down to a commutator 29 in a cylindrical brush holder 43 fixed to a holder insulator 42, the holder 43 and the brush 44 are electrically interconnected. It is provided with the holder 43, a terminal metal fitting 50 electrically connected to a path for a current flowing through an armature by being utilized as a switch contact piece together with the holder 43 and a protective switch means 47 comprising a thermally-sensitive fusing body 51 which is electrically connected at a predetermined temperature or below and cuts off the connection at a predetermined temperature or above. Between the fusing body disposing part 52 of the holder 43 in which the fusing body 51 is disposed and the brush 44, a thermal resistance means (air gap) 53 which is not brought into contact with them is provided. |
