| 摘要 |
PROBLEM TO BE SOLVED: To improve a rectification state of a speed changeable electric motor and to reduce magnetic noise and brush wear. SOLUTION: In a wiper motor, a common brush 31, a low-speed operation brush 32 and a high-speed operation brush 36 are brought into slide contact with an outer peripheral face of a commutator 28 fixed to an armature shaft 24. The low-speed operation brush 32 and the high-speed operation brush 36 are switchably energized along with the common brush 31 to change operation speed in two stages in the wiper motor. The high-speed operation brush 36 is brought into slide contact with the commutator 28 in a position shifted from the common brush 31 and the low-speed operation brush 32 in an axial direction of the armature shaft 24. A slide contact range S2 is shifted from a range S1 where the brush is brought into slide contact with the common brush 31 and the low-speed operation brush 32 in the axial direction. COPYRIGHT: (C)2010,JPO&INPIT
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