| 摘要 |
PURPOSE:To provide an element which can detect wear and temperature rise of brush of a motor through a simplified structure. CONSTITUTION:A wear detector 35 held at a fixed plate 31 is composed of a fixed contact 37 and a movable contact 39. The movable contact 39 is usually displaced toward a cover 51 because a bending part 39a projection from an angled hole 33 collides with the side surface of brush and when the brush wears and coupling between the side surface of brush and bending portion 39a is lost, the contact part 39b is placed in contact with the fixed contact 37. A thermoswitch 43 which becomes conductive under a higher temperature is connected in parallel between the fixed contact 37 and movable contact 39. The both ends of a parallel circuit consisting of the wear detector 35 and thermoswitch 43 are connected with a pair of wires 45 and temperature rise and wear of brush can be detected depending on the conductive conditions of such lead wires 45. |
