STARTER

摘要

Formed in a pinion (74) are pinion-side helical external teeth (74A) that mesh with a ring gear (23), and pinion-side helical internal teeth (74a) that mesh with a pinion inner (71). Formed in the pinion inner (71) are pinion inner-side helical external teeth (73) that mesh with the pinion-side helical internal teeth (74a). The configuration is formed so that when the rotational speed of the pinion (74) is slower than that of the ring gear (23), a thrust load is generated in a direction toward the ring gear (23), and when the rotational speed of the pinion (74) is faster than that of the ring gear (23), a thrust load is generated in a direction away from the ring gear (23).