| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem of causing failure by contact abrasion due to an applying load when rigidity reduces, since generated pressure leaks when a surface pore exists by the specific number or more, in a fluid dynamic bearing using a sleeve composed of sintered metal. SOLUTION: This fluid dynamic bearing device superior in performance at the low temperature of a bearing can be provided such that porosity of a surface of the sleeve 1 is set in a specific range, and a ridge width of a dynamic pressure groove is kept in a specific value or more, and reduction in radial bearing rigidity is prevented by preventing and eliminating leakage of dynamic pressure developed pressure, and a conventional cover can be disused, and a component of a metallic particle being a raw material of the sleeve composed of the sintered metal. is also based on iron so as to increase a linear expansion coefficient of a shaft and the sleeve on the shaft side. COPYRIGHT: (C)2009,JPO&INPIT
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