| 摘要 |
PURPOSE:To provide a dynamic-pressure fluid bearing which can use normal oil as a lubricating fluid, easily remove air bubbles and reduce bearing friction moment, by leading air kept up among a plurality of oil films to the air. 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, and oil films 30, 31, 32 are formed on those portions. A shaft 18, the flange 19 and the thrust bearing 21 are respectively provided with a hole 28, a hole 39 and holes 40, thereby leading air 37 shut up by plural oil films to the outside air. Thus, oil films can be formed on each bearing portion separately. |
