RACEWAY RING MEMBER FOR BEARING UNIT, BEARING UNIT, AND METHOD AND DEVICE FOR PRODUCING RACEWAY RING MEMBER FOR BEARING UNIT

摘要

A bearing unit having one raceway ring (2) mounted on a vehicle body, the other raceway ring (4) placed facing the one raceway ring (2) and mounted on a wheel, and rolling bodies (6, 8) rollably assembled between an outer ring raceway (2s) and an inner ring raceway (4s) that are continuously circumferentially formed on the opposite surfaces of the raceway rings (2, 4). At least either of the raceway rings (2, 4) has a joint flange (2a) or an installation flange (12a) for mounting on the vehicle body or the wheel. The entire raceway rings (2, 4) are formed by cold forging without subjecting the surface of the flange (2a, 12a) to machining, and at least the outer ring raceway (2s) and the inner ring raceway (4s) are subjected to quenching and tempering by electromagnetic induction and cutting.