| 摘要 |
PROBLEM TO BE SOLVED: To manufacture an auxiliary ring at low cost while improving durability of an inner diameter side female spline part and an outer diameter side male spline part formed in both inner and outer peripheral surfaces of the auxiliary ring. SOLUTION: The auxiliary ring 21a is manufactured as follows. Bar is cut into a specified length by shearing with a press to form a cylindrical pre- finishing material. The cylindrical pre-finishing material is then forged to form a cylindrical intermediate material formed with a grain flow in the axial direction inside thereof. Outer and inner peripheral surfaces of the cylindrical intermediate material are then formed with the outer diameter side male spline part 23 and the inner diameter side female spline part 22, respectively, to provide the auxiliary ring 21a. Since a forming direction (axial direction) of the grain flow is orthogonal to a direction of load (circumferential direction) exerted to both spline parts 22, 23, both spline parts 22, 23 are improved in durability. |
