| 摘要 |
PROBLEM TO BE SOLVED: To prevent generation of negative pressure in an internal space of a housing. SOLUTION: Lubricant in a gap of a thrust bearing of a thrust bearing section T flows to a bore side of the thrust bearing section by receiving pull-in force of a spiral hydrodynamic groove 8b1 when a shaft member 2 is rotated. Lubricant in a radial bearing gap of a first radial bearing section R1 and a radial bearing gap of a second radial bearing section R2 led to the first radial bearing section is pushed to a downward side by flowing the lubricant, and pressure of the lubricant is increased at the bottom 7c of the housing 7. The pressure-increased lubricant at the bottom 7c returns to an internal thin hole of a bearing sleeve 8 via a surface opening of an inner peripheral chamfer 8e (oil leader) of the bearing sleeve 8, and is again supplied to the thrust bearing gap from the surface opening of an upper end face 8b via the internal thin hole of the bearing sleeve 8. COPYRIGHT: (C)2007,JPO&INPIT
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