To realize structure capable of improving the rigidity of a base part of a mounting flange 9a without increasing axial dimension of a wheel supporting bearing unit.
In the outer peripheral surface of a hub 4a, the outer diameter D of a stage difference surface 12a formed between the inside surface of the mounting flange 9a and a cylindrical surface part 10, on which inner rings 2a and 2b are externally fitted, is formed larger than the outer diameter d of an outside flange part 15 of the one inner ring 2a existing outside. A combination seal ring 19a to be provided between the outside flange 15 and the inner peripheral surface of the outer ring 1 in an outer end thereof is provided so that an outside surface of an outside circular ring part 23 of a slinger 20 is not projected from the outer end surface of the one inner ring 2a. The described problem can be thereby solved.
| JP2008157327 | BEARING DEVICE FOR WHEEL |
TAKEHARA TORU
Nakai Shun
Kinzo Koyama