微孔节流气体静压止推轴承跨缝过程时变特性研究

Study on Time-Variant Characteristics of Micro-hole Throttling Aerostatic Thrust Bearing in the Process of Crossing Slots

目前,大型气浮平台均采用花岗岩平台拼接而成,平台拼缝会对实验效果产生一定影响。针对上述问题,以微孔节流气体静压轴承运动中经过平台拼缝时的时变特性为研究对象,建立微孔节流止推轴承物理模型,并使用CFD软件与UDF相结合的动网格技术实现轴承跨越平台拼缝的动态过程仿真,研究不同气膜厚度、进气口压力、平台拼缝位置对轴承承载力和压力分布的影响。结果表明:当平台拼缝到达微孔分布圆附近时承载力急速下降,且平台拼缝到达轴承中心时承载力下降到最小值;随着气膜厚度的增加,轴承承载力的最大损失比例随之增加,并最终稳定到0.6;平台拼缝位于供气孔分布圆之外时,轴承边缘与平台拼缝之间的承载面将失效;通过增加进气口压力,轴承承载力整体有明显提升,但承载力损失速度也明显加快。

At present,large air flotation platforms are made of granite platform splicing,and the slots between the splices have a certain impact on the experimental effect.Aiming at the above problems,taking the time-variant characteristics of the micro-hole aerostatic bearing crossing through the slot as the research object,the physical model of the micro-hole throttling aerostatic bearing were established,and the dynamic process simulation of the bearing crossing the slot was carried out by using the dynamic mesh technology combined with CFD software and UDF.The effects of different air film thickness,inlet pressure and slot position on load capacity and pressure distribution were analyzed.The results show that the bearing capacity decreases rapidly when the slot reaches the distribution circle of the micro-hole,and the bearing capacity decreases to the minimum when the slot reaches the center of the bearing;with the increase of gas film thickness,the maximum loss ratio of load capacity increases and finally stabilizes to 0.6;when the slot is located outside the distribution circle of the micro-hole,the bearing surfaces between the edge of bearing and the slot is not work;by increasing the inlet pressure,the overall load capacity improves significantly,but the speed of load capacity loss becomes faster too.