| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an electric motor which can prevent wrong installation at low cost and has high performance. <P>SOLUTION: In an electric motor, at least one pair of helical torsion springs 21 energizing each brush 30 from the radial outer side toward a commutator are installed in a brush holder 22. The helical torsion spring 21 includes: a spirally wound winding part 21c; a pressing part 21a extending from one end side of the winding part 21c and energizing each brush 30; and a lock part 21b extending from the other end side of the winding part 21c and locked on the brush holder 22. The pair of brushes 30 is disposed to be axisymmetrical around any straight line passing through an axial center of an armature. The brush holder 22 in the axial direction is formed so that mounting height of each of the pair of helical torsion springs 21 is changed in accordance with free length of the helical torsion spring 21. <P>COPYRIGHT: (C)2012,JPO&INPIT</p> |
