| 摘要 |
Within bounds on both sides of an axial center of each of the raceways of an outer and inner ring, a curvature radius of a raceway portion in a dimensional range covering at least 45% of a raceway width with respect to the axial center thereof is defined to be within the range of between ±1 mum to/from a mean curvature radius of the raceway in the dimensional range. |
