| 摘要 |
PROBLEM TO BE SOLVED: To provide a rolling bearing highly strong corresponding to severe working conditions, of a long life to surface damage such as surface starting separation or inside starting separation, and easy to caulk at the end. SOLUTION: The rolling bearing 20 for a planetary gear mechanism comprises an inward member 17 and an outward member 13 arranged in a concentric manner, and rolling elements laid between both members. At least one of the inward member 17 and the outward member 13 has a nitrogen enriched layer. At least one member has an austenite crystal grain size of No.11 or more and hardness of HV653 or more at the surface layer portion in a rolling surface region where the rolling elements 18 roll. It has a hardness of HV550 or more at the sectional center of a rolling surface central portion. The inward member has a hardness of HV300 or less at the end. COPYRIGHT: (C)2007,JPO&INPIT
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