Wheel bearing assembly

A wheel bearing assembly comprising:

• a wheel hub having a hub flange on which a wheel is mounted;
• at least one inner ring configured to be press-fitted and mounted to one side of the wheel hub;
• an outer ring provided radially outward of the inner ring and having a mounting flange, which is formed on an outer peripheral surface of the outer ring and on which a vehicle body is coupled;
• and
• one or more rolling elements configured to rotatably support the wheel hub and the inner ring with respect to the outer ring,
• wherein an accommodation space is formed inward of a vehicle-body-side end portion of the wheel hub to accommodate a constant velocity joint,
• wherein a plurality of recesses for accommodating rotating elements of the constant velocity joint are formed on an inner peripheral surface of the accommodation space to be spaced apart from each other along a circumferential direction,
• wherein a first heat-treated hardened portion is formed on the inner peripheral surface of the accommodation space,
• wherein the first heat-treated hardened portion is formed to include portions with which the rotating elements of the constant velocity joint are brought into contact, and
• wherein a second heat-treated hardened portion is formed on an outer peripheral surface of the wheel hub, and
• the first heat-treated hardened portion and the second heat-treated hardened portion are formed so as not to overlap each other,
• wherein a spacer is provided at the vehicle-body-side end portion of the inner ring, and
• wherein a boot fastening portion to which a rubber boot is fastened is provided radially outward of the spacer.