| 摘要 |
<p>An object of the present invention is to provide a bearing apparatus for a wheel of vehicle which can simultaneously solve the antinomic problems of reducing the weight and size of the bearing apparatus and of increasing the rigidity of the bearing apparatus. According to the present invention there is provided a bearing apparatus for a wheel of vehicle comprising an outer member (2, 30) formed on its inner circumferential surface with double row outer raceway surfaces (2a, 2b); inner members (1, 20, 29, 35, 38) each formed on its outer circumferential surface with double row inner raceway surfaces (4a, 5a, 31a) oppositely arranged to the double row outer raceway surfaces (2a, 2b); and double row ball groups (3) freely rollably contained between the outer raceway surfaces (2a, 2b) and inner raceway surfaces (4a, 5a, 31a) of the inner members (1, 20, 29, 35, 38) and the outer member (2, 30) characterized in that a pitch circle diameter (PCDo) of a ball group (3) near a wheel mounting flange (6) is larger than a pitch circle diameter (PCDi) of a ball group (3) away from the wheel mounting flange (6), and that each of corners (A, B, C, D) of shoulders of the outer and inner raceway surfaces (2a, 2b, 4a, 5a, 31a) is rounded as a smooth circular arc.</p> |
