| 摘要 |
PROBLEM TO BE SOLVED: To extend the life of a tooth surface of an external tooth 19 by suppressing the elastic deformation of a bridge section 30 in an externally toothed gear 18 and the external tooth 19, and to improve vibration characteristics.SOLUTION: Since a ratio obtained by dividing the diameter (D) of a pin constructing an internal tooth 14 by the pitch P of the internal tooth 14 is made smaller to an extent where the tooth top 19a of the external tooth 19 exceeds radially outside the inner periphery 15a of an internally toothed gear 15, the diameter D of the internal tooth (the pin) 14 becomes smaller than before. Therefore, the tooth bottom 19b of the external tooth 19 of the externally toothed gear 18 is moved radially outward. As a result, the thickness (the minimum thickness) J of the bridge section 30 becomes thicker than before, and the bending rigidity is enhanced. Thus, the elastic deformation of the bridge section 30 and the external tooth 19 due to the reaction force of a driving component force is suppressed. |
