| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a wheel bearing device keeping a light weight and compact size while assuring its strength and rigidity, improving a face deflection accuracy of a wheel fixing flange and restricting an occurrence of a brake judder. <P>SOLUTION: A recess 11 is formed at the outer periphery between each of bolt holes 6a while avoiding a location near the bolt holes 6a of a wheel fixing flange 6, the recess 11 is placed at an outer diameter part than a pitch circle diameter PCD of the bolt hole 6a, is formed in a circular arc shape to cause its deepest part 11a and the pitch circle diameter PCDb of the bolt hole 6a to approach each other, and is smoothly connected to the outer peripheral surface of the wheel fixing flange 6. The center of curvature of the recess 11 is placed on a central extending line between each of the adjoining bolt holes 6a from the center of the wheel fixing flange 6, and the radius of curvature R1 is set as R1=0.7 to 1.5 PCDb in respect to the pitch circle diameter PCDb of the bolt hole 6a. <P>COPYRIGHT: (C)2009,JPO&INPIT |
