Bearing device for wheel and manufacturing method therefor

摘要

A bearing device for a wheel includes an outer member having double-row outer raceway surfaces formed on an inner circumference thereof, an inner member including a hub wheel having a wheel mounting flange formed thereon and at least one inner race fitted to a small-diameter step portion formed on an outer circumference of the hub wheel, the inner member having double-row inner raceway surfaces formed thereon so as to be opposed to the double-row outer raceway surfaces, and a plurality of rolling elements in spaces between the double-row inner and outer raceway surfaces. The at least one inner race being fixed in an axial direction thereof by a staked portion, the staked portion having a face spline formed on an end surface thereof by plastic working.

主权项

1. A bearing device for a wheel, comprising:
an outer member having double-row outer raceway surfaces formed on an inner circumference thereof; an inner member comprising:
a hub wheel having a wheel mounting flange formed thereon; andat least one inner race fitted to a small-diameter step portion formed on an outer circumference of the hub wheel,the inner member having double-row inner raceway surfaces formed thereon so as to be opposed to the double-row outer raceway surfaces; and a plurality of rolling elements assembled into spaces between the double-row outer raceway surfaces and the double-row inner raceway surfaces, the at least one inner race being fixed in an axial direction thereof by a staked portion formed by plastically deforming an end portion of the small-diameter step portion of the hub wheel radially outward, the staked portion having a face spline formed on an end surface thereof by plastic working, wherein the following relationship is satisfied:
S/M≦α×βwhere M represents a mean diameter of an outer diameter and an inner diameter of the end portion of the small-diameter step portion of the hub wheel before the staked portion is formed, S represents an outer diameter of the face spline, α represents a value indicating ductile elongation of a material for the hub wheel in terms of proportion, and β represents a correction coefficient depending on a type of process.