| 摘要 |
A wheel rolling bearing unit has a hub spindle having flange and shaft-shaped sections, an inner-ring raceway surface on the outer peripheral surface of the shaft-shaped section; an outer ring member disposed around the outer periphery of the shaft-shaped section, an outer-ring raceway surface on the inner peripheral surface thereof; and rolling elements between the inner-ring raceway and outer-ring raceway surfaces. The flange section is on one side of the spindle in a rotation axis direction thereof; on the flange surface, a cylindrical spigot joint section protruding on one side is coaxial with the spindle; the boundary section of the flange surface and the outer peripheral surface of the spigot joint section has an arc-shaped boundary surface to connect smoothly toward the flange surface. The surface roughness of the boundary surface is finer than that of the flange surface and the outer peripheral surface of the spigot joint section.
|
