ROLLING BEARING UNIT FOR SUPPORTING WHEEL

摘要

PROBLEM TO BE SOLVED: To prevent the occurrence of damage such as a crack in a grinding relief groove part provided in a continuous part of the side face of a collar part 27 on a large diameter side formed on an outer peripheral face in the inner end part of an inner ring 10b and an inner ring raceway track 7 with particularly increasing the thickness of the collar part 27 on the large diameter side. SOLUTION: The inner end face 22 of the inner ring 10b fitted externally into a support step part 11a of an inner end part of a hub body 9c is pressed by a caulked part 13 formed in the inner end part of the hub body 9c, and the inner ring 10b is connected with and fixed to the hub body 9c. The maximum outside diameter D1 of an abutting part of the caulked part 13 on the inner end face 22 is set smaller than the diameter D2 of the bottom part of a grinding relief groove. It is possible to prevent a moment load from being applied from the collar part 27 on the large diameter side to the grinding relief groove in accordance with the formation of the caulked part 13 owing to this configuration to achieve the purpose.