| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve contactness of a recess-projection fitting structure, while preventing inappropriate inflation of a hub ring by properly managing the shape of a projecting part to form the recess-projection fitting structure for connecting a shaft part of an external joint member and the hub ring in a bearing device for a wheel. <P>SOLUTION: The projecting part 35 extending in an axial direction is provided in the shaft part 12 of a joint outer ring 5. A recessed part 36 for closely fitting the projecting part 35 to an inner diameter surface of the hub ring 1 by press-fitting the shaft part 12 into a hole part 22 of the hub ring 1 is formed to constitute the recess-projection fitting structure M. When a diameter of a circle passing a top part of the projecting part 35 in an axially perpendicular cross section at a press-fitting starting side end part is D1, a diameter of a circle passing the top part of the projecting part 35 in the axially perpendicular cross section at an axially optional position X except the press-fitting starting side end part is D2(X), tooth thickness of the projecting part 35 on a reference circle C0 in the axially perpendicular cross section at the press-fitting starting side end part is L1 and tooth thickness of the projecting part 35 on a circle C1 projected with the reference circle C0 in the axially perpendicular cross section at the optional position X is L2(X), the management is performed so that a value of ¾D1-D2(X)¾ may be ≤0.2 mm and a value of ¾L1-L2(X)¾ may be ≤0.1 mm. <P>COPYRIGHT: (C)2011,JPO&INPIT |
