| 摘要 |
PROBLEM TO BE SOLVED: To provide a dynamic pressure fluid bearing device and spindle motor capable of effectively preventing leak and scatter of lubricant and stably performing lubrication even under elevated temperature. SOLUTION: Linear expansion coefficients of a sleeve member 12 and a rotation shaft 22 are maintained high in comparison with that of a hub 20 including an outer circumference side annular part 20a. A linear expansion coefficient of an inner circumference side annular part forming member 24 is maintained high in comparison with those of the sleeve member 12 and the rotation shaft 22. Accordingly, clearances of a first interface retention part 26 and a second interface retention part 48 decrease when temperature rises. The linear expansion coefficients of the sleeve member 12 and the rotation shaft 22 are maintained in a same level to reduce clearance changes at an upper and a lower radial bearing parts 32, 34 and a thrust bearing part 46 when temperature rises.
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