| 摘要 |
PROBLEM TO BE SOLVED: To provide a spindle shaft which allows a wheel bearing device for a drive wheel to be used as a driven shaft without taking measures for conventional delay fracture.SOLUTION: A spindle shaft 61 which is attached to a hub wheel by using the drive-wheel side hub wheel 72 in which a female spline is formed at an inside diameter face comprises: a screw part 64 at a tip part; a shaft main body 62 having a male spline 65 which is formed at a base end side of the screw part via a stepped part, and toothed with the female spline 80 of the hub wheel; and a back face 67 which is continuously arranged at the shaft main body via a shaft-rooted R-part of the shaft main body. The back face is externally fit to a cylindrical shaft part of the hub wheel, and pre-compresses an inner ring by the screwing of a nut member to the screw part. An axial length of the male spline is set longer than an axial length of the female spline, the male spline and a bearing pressing part of the back face are made to be thermosetting treatment parts, and the shaft-rooted R-part is made to be a non-heat treatment part. |
