Patent ID: 7748925

Claim:
A rotating member fixing structure comprising: a shaft member having an external teeth part formed on an outer circumferential surface; and a rotating member having an internal teeth part formed on an internal circumferential surface of an axial bore section, the rotating member being fixedly coupled to the shaft member by press-fitting a bottom surface portion of the internal teeth part of the rotating member and a tip surface portion of the external teeth part of the shaft member, the shaft member including a margin adjusting part dimensioned to scratch off the bottom surface portion of the internal teeth part of the rotating member by the tip surface portion of the external teeth part of the shaft member to reduce a press-fitting margin between the shaft member and the axial bore section of the rotating member from an initial press-fitting margin to an effective press-fitting margin that is less than or equal to a prescribed value when the bottom surface portion of the internal teeth part and the tip surface portion of the external teeth part are press-fitted together, the tip surface portion of the external teeth part of the shaft member including: a first tip surface extending from a leading axial end portion of the external teeth part from which the rotating member is attached to the shaft member, and a second tip surface formed on a side of the first tip surface opposite from the leading axial end portion of the external teeth part, the second tip surface having a larger diameter than the first tip surface, the margin adjusting part including a boundary section that separates the first tip surface and the second tip surface, the margin adjusting part being dimensioned to use the boundary section as a trigger to initiate scratching off of the part of the bottom surface portion of the internal teeth part of the rotary member by the second tip surface when the bottom surface portion of the internal teeth part and the tip surface portion of the external teeth part are press-fitted together.