A planetary gear speed reduction mechanism (100) has a sun gear (1), an internal gear (2) and a plurality of planetary gears (3) disposed between both gears (1, 2). Each tooth (10) of the sun gear (1) has a tapered portion (11) formed at a front end thereo...

A shock absorber for a starter is presented. The shock absorber includes a rotary disk (20), a stationary disk (21) and a disk spring (22). The rotary disk (20) is pressed by the disk spring (22) against a stationary disk (21) to generate frictional force ...