| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a bearing device for a wheel with its product quality improved by preventing black scale from remaining in a width grinding process of the inner wheel as well as its durability improved by suppressing deformation of the inner wheel accompanying the caulking machining in a bearing device for a wheel having first to third generation structures in which the inner wheel is fixed by oscillation staking of a hub wheel. <P>SOLUTION: In the bearing device for a wheel in which the inner wheel 3 is fixed in the axial direction by a staking portion 2c formed by plastically deforming an end part of a small-diameter stepped portion 2b outwardly in the radial direction, the outer diameter portion a of the inner wheel 3 is formed so as to have a larger diameter than a pitch circle diameter PCD of a ball 6, a chamfered portion 12 is formed at the corner part of a large end surface 3b and the outer diameter portion a of the inner wheel 3, and the chamfered portion 12 is configured by an arc surface 12b and a tapered surface 12a formed in an inclined manner from a position substantially 4 mm separate from the outer diameter of the caulking portion 2c and at the same time, a ratio between a grinding width B of the large end surface 3b and a grinding width A of a small end surface 3c of the inner wheel 3 is set to B/A≤10 and a ratio of B and thickness C is set to B/C≤0.8. <P>COPYRIGHT: (C)2012,JPO&INPIT |
