| 摘要 |
PROBLEM TO BE SOLVED: To provide a wheel bearing device which increases bearing rigidity while achieving weight saving and compactification, and also achieves securement of accuracy and a long life of a bearing by suppressing stress generated in an outer member.SOLUTION: In a wheel bearing device fixed to a torsion beam type suspension, an outer peripheral surface of an outer member 2 is formed in a petal shape in which a large diameter part 17 and a small diameter part 18 are arranged alternately in a circumferential direction. A plurality of vehicle body attachment flanges 2c are formed so as to protrude radially outward from the small diameter part 18. An attachment surface 19 is formed on the inner side of the vehicle body attachment flange 2c. A screw hole 20 extending in a shaft direction is formed on the attachment surface 19, and a recessed groove 22 is formed in the vicinity of the radial inner side of the screw hole 20. Since the outer member 2 is fastened to a suspension device through a fixing bolt screwed to the screw hole 20, tensile stress generated when fastening the bolt is absorbed by the recessed groove 22, and thereby it is possible to suppress the deformation of the attachment surface 19 and prevent the roundness deterioration of an outer rolling surface 2b. |
