| 摘要 |
<p>Disclosed is a bearing device for a wheel such that separation of a hub ring and an outer coupling ring from each other is allowed, and that the abutting state between a bolt receiving surface, and a head section bearing surface of a bolt member, is made appropriate, resulting in the prevention of a reduction in a fixing force acting between an outer coupling member and the hub ring. In this bearing device, protrusions (32) which extend axially are provided on a shaft section (11) of the outer coupling ring (4), and the shaft section (11) is press-fitted into a hole (20) of the hub ring (1). Through this press-fitting operation, recesses (33) which are closely fitted over the protrusions (32) are formed on the inside diameter surface of the hub ring (1) by means of the protrusions (32), with the result that there is formed a recess-protrusion-fitting structure (M) wherein the protrusions (32) are in close contact with the recesses (33) in the whole fitting area. The hub ring (1), and the shaft section (11) of the outer coupling ring (4), are fixed to each other with a bolt member (37) in a state where it is allowed to separate the recess-protrusion-fitting structure (M) by providing an axial pull-out force. Furthermore, the squareness of a bolt receiving surface (20e1) of the hub ring (1) with respect to the inside diameter surface (34) of a shaft section fitting hole (20a) is made a subject of control, said bolt receiving surface (20e1) being abutted by a head bearing surface (37a1) of the bolt member (37). A value of 0.1 mm or less is assigned as the squareness.</p> |
