| 摘要 |
PURPOSE:To reduce dimension and weight by arranging a spring for forwardly energizing a pinion between a helical spline part, step dropped part having the less diameter than the diameter of the bottom part of the helical spline part, and the rear edge of the pinion, and inside a clutch inner. CONSTITUTION:In a starting electric motor 100a, a spring 130 for forwardly energizing a pinion 119 for softening the shock in the meshing of the pinion 119 is arranged between a helical spline part 115a of an output revolution shaft 115, step dropped part 115f having the less diameter than the diameter of the bottom part, and the rear edge of the pinion 119, and inside the helical spline 114b of a clutch inner 114a. Since the spring 130 is set behind the teeth of the pinion 119, the reduced of forming a recessed part on the pinion 119 as in the conventional is obviated, and the number of teeth of the pinion 119 can be reduced without reducing the strength at the tooth bottom, and the gear ratio can be increased. Therefore, the reduction of dimension, weight, and the length in the axial direction of the electric motor part can be reduced. |
