螺旋槽气体轴承窄槽理论方程的扰动系数修正及润滑特性分析

Perturbation Coefficient Correction and Lubrication Characteristics of Narrow Groove Theoretical Equation of Spiral Groove Gas Bearing

为了提高螺旋槽径向气体轴承理论性能预测的准确性,推导并建立关于轴承的窄槽理论润滑方程,在利用扰动法分析轴承润滑特性时,对原有窄槽理论方程中槽型相关系数的扰动系数进行修正,建立窄槽理论-扰动模型,数值求解得到轴承的静动态特性参数,并将扰动系数修正前后得到的轴承特性参数与实验数据进行对比。结果表明:利用扰动法与窄槽理论相结合分析螺旋槽气体轴承的润滑特性时,模型修正前后对于承载力影响较小,对于动态特性参数的影响较大;涡动偏心率对轴承静态承载力影响很小,对动态特性参数有显著影响,因而在利用修正模型进行轴承特性参数计算时,涡动偏心率取值建议小于0.1。模型修正后,动态特性参数计算结果更加贴近实际测量值,提高了窄槽理论-扰动模型求解轴承润滑特性的准确性。

In order to improve the precision of the theoretical performance prediction of spiral grooved journal gas bearing,a narrow groove theoretical lubrication equation concerning bearings was developed.The perturbation coefficient of the groove correlation coefficient in the original narrow groove theoretical equation was modified when using the perturbation method to analyze the lubrication characteristics of bearings.A narrow groove theory-perturbation model was established,and the static and dynamic characteristic parameters of bearings were obtained through numerical solution.The bearing characteristic parameters obtained before and after perturbation coefficient correction were compared with the experimental data.The results demonstrate that when using perturbation method and narrow groove theory to analyze the lubrication characteristics of spiral groove gas bearings,the model before and after modification has a small influence on the bearing capacity,but has a large influence on the dynamic characteristic parameters.The whirl eccentricity has little effect on the static bearing capacity of the bearing,but has a significant effect on the dynamic characteristic parameters.Therefore,when using the modified model to calculate the bearing characteristic parameters,the whirl eccentricity is recommended to be less than 0.1.After the model is modified,the calculation results of dynamic characteristic parameters are closer to the actual measured values,which improves the accuracy of narrow groove theory-perturbation model in solving bearing lubrication characteristics.