螺旋槽小孔节流动静压气体轴承稳态承载力分析

Steady-state Bearing Capacity Analysis of Spiral Groove Small Orifice Throttle Hybrid Gas Bearing

为研究空气轴承在动静压下的稳态承载性能,使用三维建模工具建立动静压气体轴承模型,从连续方程、可压缩流体润滑方程、气体状态方程出发,得到等温条件下稳态气体润滑Reynolds方程,并计算轴承稳态承载力。对螺旋槽小孔节流空气轴承结构建立三维模型,借助Fluent仿真软件对整个流体域进行仿真分析,探讨螺旋角、偏心率、槽宽比、槽深比、槽长比等参数对气体轴承承载性能的影响。结果表明:气源压力一定时,气膜承载力随着偏心率的增加呈现非线性上升趋势,随着槽宽比的增加呈现下降趋势,槽宽比越大,这种下降趋势更加明显;随着槽深比和槽长比的增加,气膜承载力呈现先增加后降低的趋势。对轴承结构进行优化,优化后的轴承承载性能更优。

In order to study the steady-state bearing performance of air bearing under static and dynamic pressure,a model of air bearing under static and dynamic pressure was established by using a three-dimensional modeling tool.Based on the continuum equation,the compressible fluid lubrication equation and the gas state equation,the steady-state gas lubrication Reynolds equation under isothermal condition was obtained,and the steady-state bearing capacity of the bearing was calculated.The three-dimensional model for the structure of gas bearing with helical groove orifices was established,the whole fluid field was simulated by Fluent,and the influence of different parameters,such as spiral angle,eccentricity,slot width ratio,slot depth ratio and slot length ratio,on the bearing performance of gas bearings was analyzed.The results show that when the air supply pressure is constant,the bearing capacity of the gas film shows a nonlinear upward trend with the increase of eccentricity,and a downward trend with the increase of slot width ratio.The larger the slot width ratio,the more obvious the downward trend of the bearing capacity.With the increase of groove depth ratio and groove length ratio,the gas film bearing capacity shows a trend of first increasing and then decreasing.The better bearing performance is achieved after the optimization of the bearing structure.