| 摘要 |
PROBLEM TO BE SOLVED: To provide a brush 7 that stabilizes the initial performance of a starter motor. SOLUTION: The brush 7 has a two-layer structure, in which a low-resistance member 7a and a high-resistance member 7b having different resistance values are stacked. The low-resistance member 7a is arranged at the entrance side to the rotational direction of a commutator, and the high-resistance member 7b at the exit side. Also, R chamfering roughly equivalent to the curvature radius of the commutator is provided on the sliding surface of the brush 7 that slidably contacts the surface of the commutator. However, flat surface portions 7c are each left at both ends in the circumferential direction of the brush 7 (the entrance and exit sides to the rotational direction of the commutator). Furthermore, when the width of the flat surface portion 7c left at the exit side of the brush 7 (= the width of the flat surface portion 7c left at the entrance side) is denoted as w and when the width of the high-resistance member 7b is denoted as W, the relation of W>w holds. Thereby, the high resistance side (the high resistance member 7b) of the brush 7 can be made to contact the commutator from an initial state, so that the initial performance of the starter motor can be stabilized. COPYRIGHT: (C)2008,JPO&INPIT
|
