弹性波箔型动压气体径向轴承的动特性研究

发布时间：2018-07-09 20:29

本文选题：波箔 + 动压　；参考：《南京航空航天大学》2011年硕士论文

【摘要】：波箔型动压气体轴承以气体为润滑剂,采用弹性箔片为支承元件,依靠柔性箔片与轴颈表面之间的相对运动所产生的气膜压力来支承转子,实现无接触悬浮。平箔和波箔、波箔和轴承壳体之间的相互摩擦作用提供较大的结构阻尼,能抑制轴承转子系统的自激涡动和低频涡动的发展,从而提高了轴承转子系统的稳定性。建立多自由度弹簧模型,分析柔性箔片的弹性变形,与箔片的壳体模型结果进行比较,耦合求解气膜厚度方程和Reynolds方程,分析轴承的静特性。波箔型气体轴承的动态刚度和动态阻尼系数是轴颈偏心率、旋转速度及轴心涡动速度的函数,是进行转子临界转速、不平衡响应计算及稳定性分析不可或缺的基本参数。用两种数值摄动法各自建立了波箔型气体轴承动态特性系数计算分析的数学模型,应用弹性板壳模型和多自由度弹簧模型分别计算了波箔及平箔的变形,应用有限差分法及有限元法对模型进行求解,从而获得了波箔型气体轴承的动态特性系数。将所得结果与已公布的试验数据对比,证明该模型的合理性和精确性,分析偏心率、轴颈转速和轴颈扰动频率对动态特性系数的影响。试验方面,设计了轴承性能测试试验台和波箔轴承,计算了转子的临界转速,所做的基础工作可为波箔型气体轴承的设计提供参考。
[Abstract]:The dynamic pressure gas bearing of wave foil type uses gas as lubricant and elastic foil as supporting element. The rotor is supported by the relative film pressure between flexible foil and journal surface to realize contactless suspension. The friction between flat foil and wave foil, wave foil and bearing shell provides large structural damping, which can restrain the development of self-excited vortex and low-frequency vortex of bearing rotor system, and thus improve the stability of bearing rotor system. A spring model with multiple degrees of freedom is established to analyze the elastic deformation of the flexible foil. Compared with the results of the shell model of the foil, the gas film thickness equation and Reynolds equation are solved by coupling, and the static characteristics of the bearing are analyzed. The dynamic stiffness and damping coefficient of the foil gas bearing are the functions of journal eccentricity, rotation speed and axial vortex velocity, which are the essential parameters for rotor critical speed, unbalance response calculation and stability analysis. Two numerical perturbation methods are used to establish the mathematical models for calculating and analyzing the dynamic characteristic coefficients of wave foil gas bearings. The deformation of wave foil and flat foil is calculated by using the elastic plate shell model and the multi-freedom spring model, respectively. The finite difference method and the finite element method are used to solve the model, and the dynamic characteristic coefficient of the gas bearing with wave foil is obtained. The results obtained are compared with the published experimental data to prove the rationality and accuracy of the model. The effects of eccentricity, journal speed and journal disturbance frequency on the dynamic characteristic coefficients are analyzed. In the aspect of test, the bearing performance test bench and foil bearing are designed, and the critical speed of rotor is calculated. The basic work can provide a reference for the design of blow-foil gas bearing.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH133.3

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