波箔型气体动压轴承转子系统的动力学特性研究

发布时间：2018-06-10 05:45

本文选题：波箔型轴承 + 气体润滑　；参考：《哈尔滨工业大学》2012年硕士论文

【摘要】：波箔型轴承是一种采用柔性支承表面的自作用式气体动压轴承，结合耐高温固体润滑技术，使之具有许多优异特点：转速高、无污染、自适应好、工作温度范围宽、结构简单、稳定性好以及寿命长等。箔片轴承在航空航天、国防、精密制造、低温制冷等领域具有广阔的应用前景和巨大的经济价值。然而，由于箔片轴承自身结构和气弹耦合问题的复杂性，其动静态性能的研究一直处于不断完善的过程中。考虑气体可压缩性和箔片弹性变形建立第一代波箔型径向气体轴承理论分析模型；采用有限差分法和松弛迭代法耦合求解气膜厚度方程以及压力控制Reynolds方程；气膜压力、气膜厚度以及载荷数值计算结果与国外文献对比，表明模型的精确性。对波箔型轴承进行静态特性分析：计算得到了气膜压力、气膜厚度、承载力、偏位角以及摩擦力矩等随转速、长径比的变化规律；对比箔片轴承和刚性表面轴承气膜压力和气膜厚度分布特点，表明箔片轴承具有更高的承载力和稳定性。采用摄动法并结合气体润滑Reynolds方程，考虑气体可压缩性、箔片变形以及箔片摩擦等因素推导出箔片轴承动态系数计算微分方程组。采用有限差分法和松弛迭代法耦合求解，，获得波箔型气体轴承的动态系数。将所得结果与已公布的实验对比，证明了该模型的合理性和精确性。分析了波箔型轴承动态特性随转速、偏心率、涡动频率、长径比以及箔片柔度系数和摩擦系数的变化规律。建立了波箔型气体轴承-Jeffcott刚性转子系统的动力学方程，运用Newmark-β数值方法分析转速、偏心率、不平衡量、半径间隙以及波箔刚度对系统动力学特性的影响，为今后转子-箔片轴承系统的设计和分析提供了理论基础。
[Abstract]:Wave foil bearing is a kind of self-acting pneumatic hydrodynamic bearing with flexible supporting surface. Combined with high temperature resistance solid lubrication technology, it has many excellent features: high speed, no pollution, good adaptability, wide temperature range and simple structure. Good stability and long life. Foil bearings have broad application prospects and great economic value in aerospace, national defense, precision manufacturing, low temperature refrigeration and other fields. However, due to the complexity of the structure and Aeroelastic coupling of foil bearings, The research of dynamic and static performance has been in the process of continuous improvement. Considering the compressibility of gas and the elastic deformation of foil, the theoretical analysis model of the first generation wave foil radial gas bearing is established. The finite difference method and relaxation iteration method are used to solve the film thickness equation and the pressure control Reynolds equation, and the numerical results of film pressure, film thickness and load are compared with the foreign literatures. The accuracy of the model is demonstrated. The static characteristics of wave foil bearing are analyzed. The variation of film pressure, film thickness, bearing capacity, offset angle and friction moment with rotating speed and aspect ratio are obtained. Compared with the film pressure and film thickness distribution of foil bearing and rigid surface bearing, it shows that foil bearing has higher bearing capacity and stability. The compressibility of gas is considered by using perturbation method and gas lubrication Reynolds equation. The differential equations for calculating the dynamic coefficients of foil bearings are derived from such factors as foil deformation and chaff friction. The finite difference method and relaxation iterative method are used to solve the dynamic coefficient of foil gas bearing. The rationality and accuracy of the model are proved by comparing the results with the published experiments. The dynamic characteristics of the foil bearing with rotating speed, eccentricity, vortex frequency, ratio of length to diameter, foil flexibility coefficient and friction coefficient are analyzed. The dynamic equations of the wave-foil gas bearing -Jeffcott rigid rotor system are established. Newmark- 尾 numerical method is used to analyze the effects of rotational speed, eccentricity, unbalance, radius clearance and foil stiffness on the dynamic characteristics of the system, which provides a theoretical basis for the design and analysis of rotor foil bearing system in the future.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH133.37

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