| 摘要 |
<p>PROBLEM TO BE SOLVED: To miniaturize an electric motor by arranging it in a different shaft relating to a steering shaft, and so as to small suppress a skeleton (length and weight) protruded to outside a diametric direction of the steering shaft. SOLUTION: In an electric motor 2, an armature shaft 11 is arranged on a different shaft relating to a steering shaft, on this steering shaft, a planet gear reduction mechanism decelerating rotation of the electric motor 2 transmitted to a pinion shaft 4 is arranged, rotation of the electric motor 2 is transmitted to a first sun gear 21 of the reduction mechanism through a third sun gear 27 meshed with an armature gear 12. In the reduction mechanism, by a switching means, in accordance with a direction of rotation of a stub shaft 3, rotation of either one of an internal gear 23 or a second sun gear 25 is regulated, by enabling the other to rotate, a direction of revolution of a first/second planet gear 22, 24 is switched.</p> |
