| 摘要 |
A starter motor for cranking an internal combustion engine includes an electric motor, a planetary gear device for reducing a rotational speed of the electric motor, and a shock-absorbing device that absorbs excessive impact transmitted from the engine to the starter motor. The planetary gear device has an annular member contacting a separating plate that separates the planetary gear device from the electric motor. A depressed portion such as a circular groove is formed on an axial end surface of the annular member. Lubricant retained in the depressed portion lubricates the end surface that rotates relative to the separating plate to absorb the excessive impact transmitted from the engine, and thereby abrasion wear of the end surface is suppressed. |
