Patent ID: 8057314
Filing Date: 2011-11-15
Classification: B60B,B60K,F16C,F16D,Y10S

Abstract:
1. A wheel bearing apparatus of an united combination of a wheel hub, a double row rolling bearing and a constant velocity universal joint comprising: an outer member integrally formed with a body mounting flange on its outer circumferential surface and with double row outer raceway surface on its inner circumferential surfaces; an inner member including a wheel hub integrally formed with a wheel mounting flange on one end, one inner raceway surface formed on its outer circumferential surface, the one inner raceway surface opposite to one of the double row outer raceway surfaces, and a cylindrical portion axially extends from the one inner raceway surface, an outer joint member forming the constant velocity universal joint is formed with another inner raceway surface on its outer circumferential surface, the another inner raceway surface is opposite to the other one of the double row outer raceway surfaces, a shaft portion axially extends from the another inner raceway surface and is adapted to be fit into the wheel hub; a plurality of rolling elements are freely rollably contained between the inner and outer raceway surfaces, respectively, of the inner member and the outer member; the wheel hub and the outer joint member are integrally connected via plastic caulking deformation by radially expanding a fitting portion of the shaft portion of the outer joint member, a hardened recessed and projected portion formed on the inner circumferential surface of the wheel hub bites into the outer circumferential surface of the shaft portion of the outer joint member; the recessed and projected portion is a crossed-groove formed by crossing substantially orthogonally a plurality of annular independent grooves formed axially along the inner circumferential surface of the wheel hub and a plurality of axial grooves formed equidistantly along the inner circumferential surface of the wheel hub, the diameter of the bottom of the annular groove is set smaller than the diameter of the bottom of the axial groove improving machining accuracy by suppressing vibration during the machining process avoiding discontinuing cutting during formation of the axial grooves after the formation of the annular grooves; and the biting of the hardened recessed and projected portion of the wheel hub into the shaft portion of the outer joint member is performed so that material of the shaft portion does not extend to the bottoms of the axial grooves and thus voids remain in the recessed portions of the axial grooves.