| 摘要 |
PROBLEM TO BE SOLVED: To provide a bearing device for an axle having stable strength by optimizing the shape of a hub shaft.SOLUTION: In the bearing device 1 for the axle which has an outer ring 11 formed with double tracks 11a, 11b on an inner peripheral portion, an inner ring 12 formed with an inner ring track 12a and small outside diameter surface 12d on an outer periphery, the hub shaft 13 formed with an axial track 13a, a cylindrical outer diameter surface 13e and a fitting portion side face 13k on an outer peripheral portion, and rolling elements 14A, 14B which roll between the track 11a of the outer ring 11 and the axial track 13a of the hub shaft and between the track 11b of the outer ring and the inner ring track 12a, and in which a pitch circle diameter of the outer side rolling elements 14A is larger than that of the inner side rolling elements 14B, the fitting portion side face 13k is linked to the cylindrical outer diameter surface 13e of the hub shaft 13 with one curvature surface 13f, and a radius of curvature R in an axial cross section of the curvature surface 13f is formed to be equal to difference between a radius of the cylindrical outer diameter surface 13e and that of the small outside diameter surface 12d of the inner ring 12. |
