Patent ID: 8020299

Claim:
A method of fastening a gear wherein the gear is fastened to a counter-joint component by press-fitting and fixing an axial end portion of the gear into a circular opening of the counter-joint component, the method including the steps of: forming a press-fitting external tooth part on the axial end portion of the gear by generating at a time of tooth cutting for the gear, wherein the press-fitting external tooth part is formed on an outer circumferential surface with press-fitting external teeth, an addendum circle of the press-fitting external teeth is larger than that of external teeth of the gear, and a tip shape of the press-fitting external teeth is made sharper than that of the external teeth of the gear; forming a press-fit bore, which has a smaller diameter than the addendum circle of the press-fitting external teeth, at the circular opening of the counter-joint component; and press-fitting the press-fitting external tooth part into the press-fit bore so as to have the press-fitting external teeth cut into an inner circumference surface of the press-fit bore.