Patent ID: 7909702

Claim:
A shaft mounting structure of a constant velocity joint, the shaft mounting structure comprising: an inner joint member having an inner circumference with an axially extending female spline formed on the inner circumference; a shaft having an outer circumference with a groove formed thereon and an end portion with an axially extending male spline formed on an outer circumference of the end portion, the male spline fitting into the female spline; and a retaining member for attaching to the groove of the shaft, the retaining member restricting an axial movement of the shaft by interfering with the inner joint member, wherein the groove is formed on a shaft middle side of the shaft compared to a position of the male spline and an outside diameter of a bottom portion of the groove is set at a value larger than a root diameter of the male spline, the shaft has a large diameter portion having a diameter larger than a crest diameter of the male spline formed on the shaft middle side, the groove being formed in the large diameter portion, and a shaft insertion side of the inner circumference of the inner joint member has formed an enlarged inside diameter portion into which the large diameter portion of the shaft is insertable, the enlarged inside diameter portion having a concavity formed therein that is capable of engaging with the retaining member attached to the groove of the shaft.