| 摘要 |
PROBLEM TO BE SOLVED: To provide a rolling bearing for a hydraulic pump having a long lifetime capable of precluding troubles resulting from poor lubricating performance, metal contacting, etc. even under a severe lubricated condition with low viscosity. SOLUTION: The rolling bearing 11 for the hydraulic pump has a nitrogen enriched layer on at least one of the bearing components as a raceway ring and rolling elements 13, in which the particle size number of austenite crystal grains in the nitrogen enriched layer is #11 or more, and the residual austenite amount is between 11% and 25%, including the limits, and the surface has a number of dimples in a minute recessed shape formed at random, wherein the surface roughness parameter Ryni of the dimpled surface is between 0.4 and 1.0, including the limits, while the surface roughness parameter Rk of the dimpled surface is no more than -1.0, and further the area rate of the dimples of the dimpled surface is 5-20%, and the mean area of the dimples of the dimpled surface is 30-100μm<SP>2</SP>. COPYRIGHT: (C)2007,JPO&INPIT
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