| 摘要 |
<P>PROBLEM TO BE SOLVED: To achieve long service life of an inner ring on the inner side where load conditions are strict, secure strength of conical rollers in an inner row, improve strength of a flange part of a hub ring, reduce flange deformation quantity when a vehicle turns, and improve rigidity and strength around wheels. <P>SOLUTION: This bearing device for a wheel is of a hub unit type, and of a plurality row conical roller bearing type. The inner ring 3 is engaged with an inner ring engagement surface 2a provided at one end of the hub ring 2, and inner side and outer side inner ring race surfaces 2b are provided in the inner ring 3 and the hub ring 2. The hub ring 2 is composed of carbon steel. A hard layer 20 of surface hardness of 58-60HRC is provided on a surface part of the hub ring 2 from the inner ring engagement surface 2a to a flange root part 22a. The inner ring 3 on the inner side and the conical rollers 5 are composed of bearing steel treated with through quenching to have surface hardness of 60HRC or more. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
