To provide a small configuration of an outer member of a tripod constant velocity joint to which a resin boot can be easily assembled.
Three track grooves 22a to 22c separated from each other by 120 are formed on the inner wall surface of a bottomed cylindrical part 12 of the outer member 14. Each of the track grooves 22a-22c comprises a bottom wall 24 formed in the direction extending along the outer peripheral surface of the bottomed cylindrical part 12 and two side walls 26, 26 raised in substantially vertical direction from the bottomed wall 24 and opposed to each other. Hardened layers 28 having a thickness of 0.8-3 mm are formed near the side walls 26, 26 by induction hardening. Since induction hardening is not applied to the bottom wall 24, no hardened layer 28 is formed near the bottom wall 24.
Toshiyuki Miyadera
Naoki Kashima
Yasuo Takubo