滚动轴承系统局部缺陷位移激励动力学建模及振动响应分析

发布时间：2018-11-04 07:50

【摘要】：滚动轴承是旋转机械中广泛应用的重要部件,随着科技不断发展,旋转机械对于轴承的要求也越来越高。因此尽早的对滚动轴承进行状态监测和故障诊断,有助于提高机械设备的精确度和稳定性;并且能够预防由于滚动轴承突然失效而造成的灾难性事故,对轴承状态监测和维护有重要的意义。1本文主要研究的内容包括:(1)建立了滚动轴承局部缺陷位移激励动力学模型。以裂纹为滚动轴承局部缺陷研究对象,将局部缺陷形貌特征简化为矩形;基于Hertz接触理论建立滚动轴承系统局部缺陷位移激励的二自由度动力学模型,对滚动轴承局部缺陷振动响应进行分析。(2)研究了弹流润滑对滚动轴承振动响应的影响作用。基于滚动轴承接触力学模型并引入弹流润滑,利用四阶龙格——库塔方法对所建模型动力学方程进行求解,并获得弹流润滑作用下滚动轴承局部缺陷激励模拟振动信号;通过实验获得试验信号,将模拟信号与试验信号相对比,验证所建模型的正确性。研究表明:润滑液对滚动轴承的振动有抑制的作用。(3)研究了滚动体滑动与轴承座对于滚动轴承振动响应的影响作用。基于前面所建的二自由度模型,在此模型的基础上加入用角位移表示的滚动体滑动与用接触刚度表示的轴承座,利用四阶——龙格库塔方法来获得振动响应。通过对振动信号的分析表明:滚动体滑动与轴承座刚度都会使振动信号幅值增大,加速轴承损坏。(4)研究了不同工作条件对滚动轴承振动响应的影响作用。通过研究所建的模型在不同缺陷大小、滚动轴承转速及外载荷条件下的振动信号,将同一状态不同条件下振动响应信号对比分析。研究表明:随着缺陷尺寸、滚动轴承转速和外加载荷增大,滚动轴承的振动响应幅值增大。
[Abstract]:Rolling bearing is an important component widely used in rotating machinery. With the development of science and technology, the requirement of rotary machinery for bearing is becoming higher and higher. Therefore, it is helpful to improve the accuracy and stability of mechanical equipment by monitoring and fault diagnosis of rolling bearing as soon as possible. And can prevent catastrophic accidents caused by the sudden failure of rolling bearings, The main contents of this paper are as follows: (1) the dynamic model of local defect displacement excitation of rolling bearing is established. Taking the crack as the research object of the local defect of rolling bearing, the feature of the local defect is simplified as a rectangle. Based on the Hertz contact theory, a two-degree-of-freedom dynamic model of local defect displacement excitation of rolling bearing system is established, and the vibration response of local defect of rolling bearing is analyzed. (2) the effect of elastohydrodynamic lubrication on the vibration response of rolling bearing is studied. Based on the contact mechanics model of rolling bearing and elastohydrodynamic lubrication, the dynamic equation of the model is solved by the fourth order Runge-Kutta method, and the simulated vibration signal of local defect excitation of rolling bearing under elastohydrodynamic lubrication is obtained. The experimental signals are obtained and the simulation signals are compared with the experimental signals to verify the correctness of the proposed model. The results show that the lubricating fluid can restrain the vibration of the rolling bearing. (3) the effects of the sliding of the rolling body and the bearing seat on the vibration response of the rolling bearing are studied. Based on the two-degree-of-freedom model established in this paper, the sliding of the rolling body represented by angular displacement and the bearing seat expressed by the contact stiffness are added on the basis of the model, and the vibration response is obtained by using the fourth-order Runge-Kutta method. The analysis of vibration signal shows that both sliding of rolling body and stiffness of bearing seat can increase the amplitude of vibration signal and accelerate bearing damage. (4) the effect of different working conditions on vibration response of rolling bearing is studied. Through the vibration signal of the model under different defect size, rolling bearing speed and external load, the vibration response signals under the same state and different conditions are compared and analyzed. The results show that the vibration response amplitude of the rolling bearing increases with the increase of the size of the defect, the rotational speed and the applied load of the rolling bearing.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH133.33

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