ENGINE STARTER APPARATUS

摘要

With respect to clutch roller (13) provided in a one-way rotating clutch gear adapted to transmit motor driving force but not to transmit engine driving force at engine start, fit by helical spline to a drive shaft adapted to rotate by driving force received from a motor member, it is intended to reduce any thermal influence induced when an excessive load over ordinary load torque acts from the engine side and accordingly attain an enhancement of durability. The clutch roller (13) is subjected to nitriding treatment by Tufftride, so that simultaneous penetration and diffusion of nitrogen are carried out, thereby forming a compound coating layer composed of superficial mixture phase and internal diffusion layer. Thus, there can be attained a reduction of thermal influence and an enhancement of durability.