运行参数对静压气体轴承动力学特性的影响

摘要

The finite difference method (FDM) coupled with proportion division method are used to solve Reynolds equation to get pressure distribution of externally pressurized gas bearings,and the lubrication equation of externally pressurized gas bearings under disturbance state is obtained to solve its dynamic stiffness coefficient and dynamic damping coefficient by using partial derivative method(PDM),both two are based on MATLAB programming.The model for numerically calculation of gas bearings has double-row gas supply orifices,and 8 orifices are uniformly distributed in each row.The effects of operating parameters such as gas supply pressure,rotating speed and eccentricity of externally pressurized gas bearings under specified structure size on its dynamic parameters and stability are analyzed.The results show that the main stiffness and damping coefficient of extemally pressurized gas bearings increase with the increase of gas supply pressure and eccentricity,the main stiffness increase with the increase of rotating speed,and the main damping coefficient decreases with the increase of rotating speed.The low frequency disturbances make gas bearing more unstable,and the stability of the bearings is improved by properly improving operation eccentricity.%基于MATLAB编程,利用有限差分法耦合比例分割法求解Reynolds方程,获得静压气体轴承的压力分布;采用偏导数方法,获得静压气体轴承扰动状态下的润滑方程,求解其动态刚度系数以及动态阻尼系数.针对双排孔供气、每排8孔均布的气体轴承模型进行数值计算,分析在特定结构尺寸下静压气体轴承的运行参数(供气压力、转速、偏心率)对其动力学参数及稳定性的影响.结果表明:静压气体轴承的主刚度和主阻尼系数随供气压力及偏心率的增加而增大,主刚度随着转速的增加而增加,主阻尼系数随转速的增加而减少;低频扰动更易使气体轴承发生失稳,适当提高运行偏心率可以提高轴承稳定性.