静圧スラスト軸受における気泡の発生限界

抄録

Bubbles will be produced in the lubricant film of hydrostatic bearings caused by the hydrodynamically generated negative pressure. The production of bubbles should be avoided because bubbles in lubricant films give the undesirable effects on bearing performances. In this study, the limit of bubbles production in the sector-shaped recesses of hydrostatic thrust bearings is experimentally and theoretically investigated. Effects of the spindle tilt on bubbles production in recesses are also analysed. The analysis lead to the results as follows. (1) Bubbles production in recesses are caused by the air drawing through the bearing clearance or the so-called aeration. (2) The limit of bubbles production is given in terms of the speed parameter and the tilting ratio. (3) The bubbles production in recesses can be supposed theoretically by calculating the region of the negative pressure in the lubricant film by means of the finite element method.