摘要 |
PROBLEM TO BE SOLVED: To obtain long service life even under the condition that thickness of an oil film is extremely small in low viscosity and diluted lubrication. SOLUTION: Numerous recessed parts having a minute recessed shape are provided on a surface of at least a rolling body of the bearing for the planetary gear device in a random manner. Surface roughness parameter Ryni of the face provided with the recessed parts is in a scope of 0.4 to 1.0μm, and an Sk value is -1.6 or less. COPYRIGHT: (C)2006,JPO&NCIPI
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