| 摘要 |
PURPOSE:To provide a dynamic pressure fluid bearing which can perpetuate an oil film of a bearing portion by providing a reserve lubricating fluid retaining portion near the bearing portion so as to use normal oil as a lubricating fluid and easily remove an air bubble. CONSTITUTION:The inner surface of a disc 20, the outer periphery of a flange 19 and the lower surface of a thrust bearing 21 are respectively provided with small grooves 22-25 which are positioned adjacent to helical groove arrays 26-28 and a spiral groove group 29. These groove array and groove group portions have a clearance for a bearing smaller than the other portions. Oil forming these oil films penetrates into clearances corresponding to the groove arrays and the groove group and the small grooves adjacent to the clearances to be kept therein by capillarity. |
