| 摘要 |
A bearing device for a wheel, which is reduced in weight and size with the strength and rigidity maintained at high levels and in which occurrence of a brake judder is suppressed by improving the accuracy relating to surface runout of a wheel mounting flange. Cutouts (11) are formed in a wheel mounting flange (6), at those portions of its outer periphery which are between bolt holes (6a) except in the vicinities of the bolt holes (6a). The cutouts (11) are formed in a circular arc shape such that the cutouts (11) are located outside radially of the pitch circle diameter PCDb of the bolt holes (6a), deepest portions (11a) of the cutouts (11) and the pitch circle diameter PCDb are close to each other so that the cutouts (11) and the outer peripheral surfaces of the wheel mounting flange (6) are smoothly interconnected, the center of the curvature of each cutout (11) is located on a line extending from a line drawn from the center of the wheel mounting flange (6) to the center between adjacent bolt holes (6a), and the magnitude of the curvature radius R1 of the cutout (11) relative to that of the pitch circle diameter PCDb of the bolt holes (6a) is within the range of 0.7 PCDb to 1.5 PCDb. |
