油润滑弹性支撑多叶箔片轴承特性研究

发布时间：2018-11-04 21:05

【摘要】：箔片轴承是一种柔性表面动压轴承，具有转速高、抗冲击性能好等优点。本文以提高箔片轴承承载力为目的，提出了两种新型带有弹性支撑结构的多叶箔片轴承，研究该新型箔片轴承的静态、动态特性，同时与普通圆周径向轴承、没有支撑结构的多叶箔片轴承进行对比研究，设计并加工出单弹簧支撑的多叶箔片轴承，搭建了研究油润滑多叶箔片轴承动态、静态特性的试验台，给出了油润滑多叶箔片轴承动力系数识别方法，进行了静态、动态特性实验研究。根据新型多叶箔片轴承的几何结构，建立无弹性变形时的油膜厚度模型；应用卡氏定理计算弹性支撑结构与悬臂弯曲梁的整体柔度矩阵，并通过有限元法验证该算法的准确性；将弹性支撑结构与悬臂弯曲梁的整体柔度矩阵带入静态、动态流体润滑雷诺方程，求解带有弹性支撑结构的多叶箔片轴承静态、动态特性。应用Routh-Hurwitz轴承稳定性判定方法判定该结构箔片轴承的稳定性，研究表明所设计的箔片轴承在高速时具有较高的稳定性，且无量纲临界质量提高。结合所设计的箔片轴承结构参数，完成了油润滑单弹簧支撑多叶箔片轴承的加工和制造。同时设计了油润滑多叶箔片轴承动力系数识别实验台、油润滑多叶箔片轴承承载力测量实验台。实验台包括刚性高速涡轮转子系统、润滑油系统、静载荷加载系统、动载荷加载系统、箔片温度测量系统、参数测量系统。最后设计了采用载荷增量法测量弹性支撑结构径向刚度实验台，所测量的弹性支撑结构包括卧式弹簧、波箔。最后，依据搭建的实验台对油润滑多叶箔片轴承进行静态、动态实验研究。提出基于轴承相对转子响应、激振力的同频箔片轴承的动力系数识别算法。将测得的两组互不相关的数据经过FFT变换，根据识别算法计算出多叶箔片轴承的动力学系数；承载力是依据转子与平箔发生接触摩擦时判定的。箔片轴承达到承载极限，转子与承载的箔片发生摩擦，引起箔片温度发生突变。同时将实验结果与理论值比较分析，，验证理论模型的准确性。
[Abstract]:Foil bearing is a flexible surface hydrodynamic bearing with high speed and good impact resistance. In order to improve the bearing capacity of foil bearing, two new types of foil bearing with elastic supporting structure are proposed in this paper. The static and dynamic characteristics of the new foil bearing are studied. The multi-leaf foil bearing with no supporting structure was studied, and the multi-leaf foil bearing supported by single spring was designed and machined. A test bed was built to study the dynamic and static characteristics of oil-lubricated multi-leaf foil bearing. The identification method of dynamic coefficient of oil lubricated multi-blade foil bearing is presented. The static and dynamic characteristics of the bearing are studied experimentally. According to the geometrical structure of the new multi-leaf foil bearing, the oil film thickness model is established under the condition of non-elastic deformation, the integral flexibility matrix of the elastic bracing structure and the cantilever bending beam is calculated by using Carson's theorem, and the accuracy of the algorithm is verified by the finite element method. The flexible matrix of elastic braced structure and cantilever bending beam is introduced into the static and dynamic fluid lubrication Reynolds equation to solve the static and dynamic characteristics of multi-leaf foil bearing with elastic braced structure. The stability of the foil bearing is determined by Routh-Hurwitz method. The results show that the designed foil bearing has high stability at high speed and the dimensionless critical mass is improved. Based on the structural parameters of foil bearing, the machining and manufacture of oil lubricated single spring supported multi-leaf foil bearing is completed. At the same time, an oil lubricated multi-leaf foil bearing dynamic coefficient identification test bench and oil lubricated multi-leaf foil bearing capacity test bench was designed. The test bench includes rigid high speed turbine rotor system, lubricating oil system, static load loading system, dynamic load loading system, chaff temperature measuring system and parameter measuring system. Finally, an experimental platform is designed to measure the radial stiffness of elastic bracing structure using load increment method. The measured elastic support structure includes horizontal spring and wave foil. Finally, the static and dynamic experiments of oil-lubricated multi-leaf foil bearing are carried out. An algorithm for identifying the dynamic coefficients of foil bearings with the same frequency based on the rotor response and excitation force is proposed. The dynamic coefficients of multi-leaf foil bearing are calculated by FFT transform and the bearing capacity is determined by contact friction between rotor and flat foil. The chaff bearing reaches the bearing limit, and the rotor fricts with the loaded foil, which causes the chaff temperature to change. At the same time, the experimental results are compared with the theoretical values to verify the accuracy of the theoretical model.
【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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