Patent ID: 7874735
Filing Date: 2011-01-25
Classification: B60B,F16C

Abstract:
1. A vehicle wheel bearing apparatus for a wheel of vehicle comprising: an outer member formed with double row outer raceway surfaces on its inner circumferential surface; an inner member including a wheel hub having an integrally formed wheel mounting flange at one end and a cylindrical portion axially extending from the wheel mounting flange; an inner ring press fit onto the cylindrical portion, said inner ring formed with one of two double row inner raceway surfaces on its outer circumferential surface, said inner raceway surface arranged opposite to one of the double row outer raceway surfaces; double row rolling elements freely rollably retained and held by cages between the double row outer raceway surfaces of the outer member and the double row inner raceway surfaces of the inner member; an end face at the outboard side of the inner ring is adapted to abut a stepped portion formed on the wheel hub, said inner ring secured on the wheel hub by being sandwiched between a caulked portion and said stepped portion, said caulked portion formed by radially outwardly plastically deforming an end at the inboard side of the cylindrical portion of the wheel hub; and a ratio (α) of the thickness of an end of the inner ring (e), at the outboard side of the inner ring to abut the stepped portion, relative to the inner diameter of the inner ring (d) (α=e/d), is limited at or smaller than a predetermined value, the dimensional ratio of the inner ring is set in order to provide the vehicle wheel bearing apparatus with an optimized amount of axial deformation of the inner ring caused by the caulking process and thus can assure necessary axial force and fastening strength in order to improve the strength and rigidity of the bearing apparatus.