柔性铰链可倾瓦动压轴承轴心轨迹的理论与实验研究

发布时间：2018-05-27 01:28

本文选题：柔性铰链可倾瓦轴承 + 轴心轨迹　；参考：《山东大学》2017年硕士论文

【摘要】：可倾瓦轴承是滑动轴承的一种,其具有噪音小、摩擦功耗小、运转平稳等特点,但这种轴承因结构缺陷而造成了大量的事故,因此需要对其结构形式进行改进创新。柔性铰链可倾瓦轴承是一种新形式的可倾瓦轴承,将轴瓦与轴承主体通过柔性铰链连接,进行一体化加工,代替摆动支点,既摒弃了普通可倾瓦轴承的机构复杂、非承载瓦空载时具有不稳定性等诸多缺点,同时具备了它的各种优良特性,具有明显的优势。本论文基于柔性铰链可倾瓦轴承,对柔性铰链结构、轴承动静特性及实现预定轨迹的主动控制方法进行了详细的研究,并利用实验台得出了转子的非线性轴心轨迹。主要的研究内容有以下几点:首先,本文通过有限差分方法根据雷诺方程计算了轴承的油膜压力分布与油膜合力。运用三维制图软件对轴瓦铰链结构进行建模,并使用有限元法分析了其固有频率等结构特性,然后用实验的方法测量了轴瓦的固有频率,将实验数据与模拟仿真结果进行对比,最终得到了柔性铰链结构刚度与阻尼系数。其次,本文基于柔性铰链可倾瓦轴承转子重力、非线性油膜力以及所受动载荷建立了转子运动模型,运用欧拉算法得出了转子在一段时间内完整的非线性轴心轨迹,同时运用四阶五级Runge-Kutta-Felhberg算法得出了四个轴瓦的摆动规律。在考虑轴瓦摆动自由度的前提下计算出了轴承的八个折合动特性系数,并将非线性轴心轨迹与动特性的计算方法结合,计算出了系统在特定工况前提下的随时间变化的动特性系数,即连续动特性。然后,本文提出了在轴瓦瓦背安装压电致动装置的主动控制方法。通过控制轴瓦摆角抑制转子振动。计算了轴瓦摆角规律改变对非线性轴心轨迹的影响,并推导了压电装置施加控制力与轴瓦摆角的关系。提出了基于预定轴心轨迹的轴瓦摆角计算方法,根据预定轨迹计算出了特定轴瓦的摆动规律,并进行了仿真验证。最后,本文搭建了柔性铰链可倾瓦轴承转子系统实验台,运用电涡流传感器和测试仪器对不同转速下转子的非线性轴心轨迹进行了测试,并通过设计滤波器对所测数据进行了分析处理,得出了实际工况条件下的非线性轴心轨迹。本文的研究对柔性铰链可倾瓦轴承的现实应用与主动控制具有较大的现实价值。
[Abstract]:The tilting bearing is a kind of sliding bearing, which has the characteristics of small noise, small friction power and smooth operation. But this kind of bearing has caused a lot of accidents because of structural defects. Therefore, it needs to improve its structure. The flexible hinge tilting bearing is a new form of tilting bearing, which passes the axle bush to the bearing body. Flexible hinges are joined together to carry out integrated machining, instead of swinging pivot, which not only discards the complicated mechanism of the ordinary tilting bearing bearing, but also has many advantages, such as the unstability of the non bearing tile, and has its distinct advantages. This paper is based on the flexible hinge bearing, the flexible hinge structure and the bearing. The dynamic and static characteristics and the active control method to realize the predetermined trajectory are studied in detail, and the nonlinear axis trajectory of the rotor is obtained by using the experimental platform. The main research contents are as follows: first, the paper calculates the oil film pressure distribution of the bearing and the combined force of the oil film by the Reynolds equation by the finite difference method. The structure of the axle bush hinge is modeled by the software, and the natural frequency and other structural characteristics are analyzed by the finite element method. Then the inherent frequency of the axle bush is measured by the experimental method. The stiffness and damping coefficient of the flexible hinge are obtained by comparing the experimental data with the simulation results. Secondly, this paper is based on the flexure hinges. The rotor motion model is established for the rotor gravity, nonlinear oil film force and the dynamic load of the bearing. The whole nonlinear axis trajectory of the rotor in a period of time is obtained by Euler algorithm. The four order five grade Runge-Kutta-Felhberg algorithm is used to get the swing law of the four axle bush. The eight dynamic characteristic coefficients of the bearing are calculated, and the dynamic characteristic coefficient of the system is calculated under the precondition of a specific working condition, that is, the continuous dynamic characteristic. Then, the active control method of the piezoelectric actuating device on the back of the axis is put forward. The vibration of the rotor is controlled by the control of the swing angle of the axle bush. The influence of the change of the swing angle of the Bush on the trajectory of the nonlinear axis is calculated. The relation between the control force exerted by the piezoelectric device and the swing angle of the axle bush is derived. The calculation method of the swing angle of the axle bush based on the trajectory of the predetermined axis is put forward, and the swing law of the specific axle bush is calculated and the method is carried out according to the predetermined trajectory. Finally, the experiment platform of the flexible hinge tilting bearing rotor system is built in this paper, and the eddy current sensor and test instrument are used to test the nonlinear axis trajectory of the rotor at different speeds, and the analysis of the measured data is carried out by the design filter, and the nonlinear axis under the actual working condition is obtained. The research in this paper has great practical value for the practical application and active control of flexible hinge tilting pad bearings.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH133.3

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