| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a gear which can reduce friction coefficients of tooth faces while suppressing an increase of an engagement position at torque transmission.SOLUTION: In a gear in which coating layers 1 for reducing friction coefficients are formed at tooth faces, the coating layers 1 are formed in abutting parts which contact with the tooth face of a mating gear when transmitting torque smaller than preset torque out of the tooth faces, and also in portions which do not contact with the toot face of the mating gear when transmitting the torque smaller than the preset torque.</p> |
