| 摘要 |
One object of the present invention is to provide a wheel bearing apparatus which can improve the yield of blank and reduce the manufacturing cost with reducing the number of process steps. According to the present invention there is provided a wheel bearing apparatus comprising an outer member formed on its outer circumference with a body mounting flange to be mounted on a knuckle and its inner circumference with double row outer raceway surfaces; an inner member formed on its outer circumference with double row inner raceway surfaces opposing respectively to one of the double row outer raceway surfaces; and double row rolling elements freely rollably contained between the double row inner raceway surfaces and the outer raceway surfaces of the inner member and the outer member characterized in that a plurality of bolt insertion bores through which fastening bolts to be fastened to the knuckle are inserted are formed on the body mounting flange at plurality of positions circumferentially along the body mounting flange, that the outer member is previously formed by hot forging, and that a seating surface of the fastening bolts is formed on an outboard-side surface of the body mounting flange by cold forging. |
