| 摘要 |
PROBLEM TO BE SOLVED: To provide a bearing device for a wheel capable of improving working efficiency and reducing the cost, and capable of prolonging the life of a bearing and improving product quality through the removal of scale generated in heat treatment.SOLUTION: An outer member 10 is made of medium-high carbon steel containing 0.40-0.80 wt.% carbon, a hardened layer 12 having prescribed surface hardness in a range of 58-64 HRC is formed in an area from double rows of outer raceway surfaces 10a, 10a to a seal fitting surface 10d by induction hardening, the hardened layer 12 of the seal fitting surface 10d is not exposed to an end surface of the outer member 10, and a non-hardened layer (a) is provided on an end thereof, and the double rows of the outer raceway surfaces 10a, 10a are regulated to have the prescribed surface roughness by superfinishing after cutting the hardened steel, and the seal fitting surface 10d is regulated to have the surface roughness of Ra 0.63 or less by cutting the hardened steel. |
