气浮推力轴承支撑平台平衡机制及静特性分析

摘要

A scheme of micro-gravity platform based on the gas film thrust pad bearing was proposed to mitigate and eliminate the influence of gravity.The platform includes the gas supply system of the pump,control system,gas thrust bearing and load platform.The gap between bearing and platform was applied to eliminate the gravity effect by adjusting the film thickness.Air dynamic lubrication couple models were established,including the model of the air film distribution and flow velocity,the model of the pressure distribution and gas flow,and Reynolds equation of the compressible gas and the relation of the pressure and load.The relations between air viscosity coefficients in typical working conditions,speed and loading of platform were solved by the numerical methods.The key parameters of bearing,such as minimum gas film thickness,the flow rate and power loss,were obtained.The results show the performance parameters (the minimum gas film thickness,the flow rate and power loss) are increased with the increasing of air viscosity and speed.With the increasing of the loading of the platform,the minimum gas film thickness and the flow rate are decreased.%为消除或者减弱重力的影响,提出一类气浮推力轴承支撑平台方案,包括供气系统、控制系统、推力轴承、支撑平台,该平台通过调整推力轴承与平台之间间隙的气膜厚度可消减重力效应.构建该类气体推力轴承支撑方案的气体动力润滑耦合模型,包括气体分布与流速模型、压力分布与流量模型、可压缩气体的雷诺方程和气体压力与载荷关系.数值求解上述耦合模型,获得气体黏度系数、速度、平台载荷与轴承性能参数之间的关系.结果表明:在典型工况条件下,动力黏度系数越大,最小气膜厚度、流量和功耗随之增大;最小气膜厚度、流量和功耗也随速度的增大而增加;平台载荷的增加会导致气膜厚度和流量的降低.