动静压柔性铰链可倾瓦轴承动态特性与主动控制研究

发布时间：2018-06-28 03:58

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

【摘要】：柔性铰链可倾瓦轴承不仅同普通可倾瓦轴承一样有优良稳定性。同时可以克服普通可倾瓦轴承结构复杂,加工装配要求高,支点易磨损,容易形成误差累积,易产生轴瓦颤振等缺点。动静压轴承既有动压性能也有静压性能,一些学者尝试了将可倾瓦轴承和动静压轴承结合在一起,以使其兼具两者优点,并证明了将静压引入可倾瓦轴承的可行性以及其相对于普通可倾瓦轴承和动静压轴承的优越性。但这些研究中轴承并没有采用柔性铰链结构,仍存在支点结构复杂、加工装配要求高的问题。针对上述问题,本文在柔性铰链可倾瓦轴承的基础上引入静压腔,研究了带有静压腔的柔性铰链可倾瓦轴承。在柔性铰链中加工进油孔,为静压腔供油。这样就简化了支点结构,克服了普通支点结构的诸多缺点。本文将从轴承的结构设计到轴承静态特性分析,受载荷后轴心轨迹的响应以及对轴心振动的主动控制等方面进行研究,对该类新型可倾瓦轴承的工程应用提供了理论指导意义。主要内容如下:设计了该轴承的结构,设计了通过在柔性铰链中加工进油孔的方式给轴承静压油腔供油。通过建立动静压柔性铰链可倾瓦轴承计算模型,给出了油膜厚度表达式及润滑雷诺方程。采用有限差分法,超松弛迭代法离散求解了雷诺方程,结合牛顿迭代法计算了轴颈轴瓦平衡时的轴承静态性能。对比了不同偏心率、转速和静压油腔尺寸的情况下轴承承载系数、流量系数、摩擦系数及功耗的变化,获得了轴承在一定工况下的静态性能参数。建立了轴承—转子系统轴心轨迹和轴瓦摆动的计算模型。采用欧拉法计算了动载荷作用下非线性轴心轨迹及轴瓦摆动位移。分析了轴颈受阶跃载荷、矩形脉冲载荷和三角脉冲载荷等非周期性载荷作用时的轴心轨迹瞬态特性,以及不平衡载荷作用时的轴心轨迹周期特性。分析比较了不同载荷对主要参数的影响。最后针对轴颈受动载荷时轴心发生的振动做了主动控制。通过主动控制轴瓦的摆动来改变油膜压力,进而实现对轴颈振动的抑制。给出了两种控制方法,即基于预定轨迹的控制方法和基于反馈调节的控制方法。给出了对轴心振动主动控制的实例,计算结果表明两种控制方法均实现减小轴心振动的目的。
[Abstract]:Flexible hinged tilting pad bearings are not only as stable as ordinary tilting pad bearings. At the same time, it can overcome the disadvantages such as complicated structure of ordinary tilting pad bearing, high requirement of machining and assembly, easy wear and tear of fulcrum, easy to form error accumulation and easy to produce flutter of bearing bush. The hydrostatic bearing has both dynamic and static pressure performance. Some scholars have tried to combine the tilting pad bearing with the hydrostatic bearing to make it have the advantages of both. The feasibility of introducing static pressure into tilting pad bearing and its superiority over ordinary tilting pad bearing and hydrostatic bearing are proved. However, the flexure hinge structure is not used in these researches, and there are still some problems such as complex fulcrum structure and high requirement of machining and assembling. To solve the above problems, the static pressure chamber is introduced into the flexible hinged tilting pad bearing, and the flexible hinge tilting pad bearing with the static pressure chamber is studied in this paper. The oil intake hole is processed in the flexure hinge to feed oil to the hydrostatic chamber. This simplifies the fulcrum structure and overcomes many shortcomings of the ordinary fulcrum structure. In this paper, the structural design of the bearing, the analysis of its static characteristics, the response of the axis track after the load and the active control of the vibration of the shaft center are studied, which provides theoretical guidance for the engineering application of this kind of new tilting pad bearing. The main contents are as follows: the structure of the bearing is designed and the oil supply to the hydrostatic oil chamber of the bearing is designed by processing the intake hole in the flexure hinge. The formula of oil film thickness and the Reynolds equation of lubrication are given by establishing a dynamic and static pressure flexible hinge tilting pad bearing calculation model. The Reynolds equation is solved discretely by the finite difference method and the overrelaxation iteration method, and the static performance of the bearing is calculated with Newton iteration method. The bearing load coefficient, flow coefficient, friction coefficient and power consumption under different eccentricity, rotational speed and hydrostatic pressure cavity size are compared, and the static performance parameters of bearing under certain working conditions are obtained by comparing the variation of bearing load coefficient, flow coefficient, friction coefficient and power consumption. The calculation model of bearing-rotor system axis trajectory and bearing bush swing is established. The nonlinear axis trajectory and bearing displacement are calculated by Euler method. The transient characteristics of the axis locus under the action of step load, rectangular pulse load and triangular pulse load are analyzed, as well as the periodic characteristics of the axis trajectory under unbalanced loads. The effects of different loads on the main parameters are analyzed and compared. Finally, active control is made for the vibration of the shaft center when the journal is subjected to dynamic load. The oil film pressure can be changed by controlling the swinging of the bearing bush, and the vibration of the journal can be suppressed. Two control methods are presented, one is based on predetermined trajectory and the other is based on feedback regulation. An example of active control of axial center vibration is given. The calculation results show that both control methods achieve the purpose of reducing axis center vibration.
【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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