| 摘要 |
<p>An object of the present invention is to enhance assemblability of a wheel bearing device, and stably maintain predetermined torque transmissibility over a long period of time. A shaft portion (12) of a joint outer ring (5) where projections (35) extending in an axial direction are provided is press-fitted into a hole portion (22) of a hub wheel (1) to thereby form recesses (36) by the projections 35 in an inner diameter surface (37) of a shaft fitting hole 22a of the hub wheel (1), by which a recess-projection fitting structure M is constructed, where an entire area of fitting sites of the projections (35) and the recesses (36) are brought into close contact. Moreover, a bolt member (50) is fastened in a bolt hole (13) provided in the shaft portion (12) of the joint outer ring (5) after the construction of the recess-projection fitting structure (M), which restricts separation between the hub wheel (1) and the joint outer ring (5). As the bolt member (50), if an outer diameter of a seating surface thereof (50a1) is d1 and a shaft diameter is d2, a bolt member satisfying a relational expression of 2.3 ‰¤ (d1 /d2) 2 ‰¤ 4.9 is used.</p> |
