滚动轴承缺陷非线性激励机理与建模研究

发布时间：2018-04-16 01:18

本文选题：滚动轴承 + 缺陷　；参考：《重庆大学》2014年博士论文

【摘要】：据统计，旋转机械30%的故障和大型异步电机44%的故障是由故障轴承引起的。滚动体在通过缺陷位置时会产生冲击脉冲，其冲击脉冲的幅度和波形与缺陷的形状和尺寸直接相关，，对缺陷形状和尺寸与其冲击脉冲波形之间的关系和冲击脉冲响应特征的认识程度将直接影响轴承运行状态判定的正确性与可靠性。因此，要准确预测和识别轴承早期故障，防止因轴承突发故障造成的重大经济损失和人员伤亡，需要解决滚动轴承内部早期缺陷故障诱发的非线性激励机理及其振动响应特征这个基础性关键科学问题。然而，轴承内部接触的非线性、轴和轴承座的耦合作用等因素的存在，以及滚动轴承经常处于变速和变载工况等因素的影响，对滚动轴承故障，尤其是早期局部缺陷故障的形状和尺寸与其冲击响应特征之间的关系尚未解明，制约了早期故障诊断的准确性和可靠性。因此，开展滚动轴承早期缺陷故障非线性激励机理及建模方法的研究，具有重要的理论意义和实际工程应用价值。针对滚动轴承缺陷非线性激励机理与建模问题，开展波纹度和局部缺陷激励机理，时变位移激励和时变接触刚度激励耦合的滚动轴承缺陷动力学建模，滚动轴承缺陷边缘形貌特征演变的内部激励机理及动力学建模，轴-滚动轴承-轴承座系统内部激励的振动传递与动力学建模，以及台架实验验证等研究工作。论文的主要研究内容： ①针对目前时变位移激励均匀波纹度模型难以准确描述均匀和非均匀波纹度诱发的滚动体与波纹度滚道之间时变接触刚度激励的问题，提出了时变位移激励和时变接触刚度激励耦合的滚动轴承波纹度动力学模型，分析了波纹度波数、幅值和非均匀分布形式对滚动体与内、外圈滚道波纹度表面之间的接触刚度和振动响应特征的影响规律，揭示了波纹度与滚动轴承通过频率及边频之间的关系。 ②针对目前基于单一函数的时变位移激励局部缺陷动力学模型不能准确描述实际局部缺陷表面轮廓诱发的振动响应特征问题，基于局部缺陷的实际表面轮廓形态特征，提出了滚动轴承滚道表面局部缺陷表面轮廓特征的简化表征模型，查明了不同轮廓特征局部缺陷的内部激励机理及其冲击响应特征，提出了不同轮廓形貌局部缺陷诱发冲击波形的基本表征模型，并通过台架实验验证了模型的正确性。 ③基于分段函数提出了时变位移激励和时变接触刚度激励耦合的滚动轴承局部缺陷动力学模型，克服了基于单一函数的时不变和时变位移激励局部缺陷模型无法描述局部缺陷边缘的弹性变形与局部缺陷深度对轴承振动响应特征影响的不足，创新了目前基于单一函数的局部缺陷模型，经与台架实验测试结果进行对比分析，验证了模型及其计算结果的正确性，解决了不同类型局部缺陷的内部激励表征与动力学建模难题。 ④基于滚动体与局部缺陷形貌特征及接触内在关系表征的思想，构建了局部缺陷边缘形貌特征演变诱发时变位移激励、时变接触刚度激励与局部缺陷尺寸之间关系的表达式，并基于Hertz接触理论建立了滚动轴承局部缺陷边缘形貌特征演变动力学模型，克服了基于尖锐边缘假设的滚动轴承局部缺陷动力学模型无法准确描述缺陷边缘形貌特征演变对滚动体与缺陷边缘之间的接触刚度及振动响应特征的缺点，创新了滚动轴承局部缺陷动力学模型，为滚动轴承局部缺陷边缘形貌特征随机演变动力学的建模奠定了基础。 ⑤考虑滚动体与滚道之间、轴承外圈与轴承座之间弹性界面的影响，提出了弹性界面的轴-滚动轴承-轴承座系统内部激励的振动传递动力学模型，克服了目前刚性界面的轴-滚动轴承-轴承座系统内部激励振动传递动力学模型，无法准确描述轴承内部激励引起的轴承外圈与轴承座振动响应特征之间的差异，以及不能解释轴承内部激励振动与轴承座振动之间的传递机理的缺点，研究了轴承内部激励沿轴-滚动轴承-轴承座系统弹性界面的振动传递规律，经与台架实验结果进行对比分析，验证了模型的正确性。
[Abstract]:According to statistics, 30% of the rotating machinery fault and large induction motor 44% is caused by the fault of bearing. The rolling body will produce the shock pulse through the defect position, shape and size of the pulse amplitude and waveform and the defect is directly related to the shape and size of defects and the impact of the relationship between pulse wave and shock the impulse response characteristics of awareness will directly affect the accuracy and reliability of the running state of bearing judge. Therefore, to accurately predict and identify bearing fault, caused by the sudden failure of the bearing to prevent major economic losses and casualties, to solve the nonlinear excitation mechanism and vibration response characteristics of the foundation of the key scientific problems in rolling bearing internal defects early fault induced.
However, nonlinear contact bearings, shaft and bearing seat coupling effect and other factors, as well as the rolling bearing is often in the influence of variable speed and load conditions, the rolling bearing fault, especially the early local defect shape and size and the impact response relationship between features not yet clear, restrict the accuracy and the reliability of early fault diagnosis. Therefore, to carry out research on rolling bearing fault early nonlinear incentive mechanism and modeling methods, has important theoretical significance and practical value in engineering application.
According to the bearing defect nonlinear excitation mechanism and modeling of rolling development, waviness and local defects of incentive mechanism, the time-varying dynamics modeling of bearing fault displacement excitation and time varying contact stiffness excitation coupling, and dynamics of internal incentive mechanism evolution of rolling bearing defect edge Morphology Modeling, the shaft rolling bearing vibration of internal incentive system bearing transmission and dynamic modeling, and bench experiments. The main contents of this thesis:
1. Aiming at the time-varying displacement excitation uniform waviness model is difficult to accurately describe the uniform and non-uniform waviness induced by rolling raceway waviness and contact stiffness between time-varying incentive problems, put forward the time-varying dynamic model of rolling bearing waviness due to displacement excitation and time varying contact stiffness excitation coupling, analysis the ripple of the wave amplitude and the non-uniform distribution form of rolling body and the inner and outer ring road between the waviness of surface contact stiffness and vibration characteristics response, reveals the waviness and the rolling bearing through the relationship between the frequency and the side frequency.
The present is based on a single function of the variable displacement excitation can not accurately describe the dynamics model of local defect response characteristics of vibration induced by the actual local defect surface profile, surface characteristics of actual contour defects based on a simplified model of rolling characteristics of road surface characterization of partial defect surface profile of rolling bearings, find out the internal incentive mechanism and the impact of different profile characteristics of the local defect response characteristics, and puts forward the basic characterization models with different profile of local defects induced by shock wave, and the correctness of the model is verified by bench test.
Based on the piecewise function is proposed for time-varying dynamic model of rolling bearing defect displacement excitation and time varying contact stiffness excitation coupling, overcomes the shortcomings of characteristics of elastic deformation and local defect depth based on a single function of time invariant and time-varying displacement excitation local defect model cannot describe local defect edge response on bearing vibration. The current innovation based on local defect model of single function, the test and bench test results were analyzed to verify the correctness of the model and the calculation results, solve different types of defects of internal incentive characterization and dynamic modeling problem.
The rolling body and the feature of partial defects and the inherent relationship between contact characterization based on the idea of constructing the local defect edge morphology evolution induced by time-varying displacement excitation, and the relationship between the expression of time-varying contact stiffness excitation local defect size, and contact is established based on the theory of rolling bearing local defect edge morphology evolution dynamics model based on Hertz. To overcome the defects of the local dynamics model of rolling bearing the sharp edges of the hypothesis cannot accurately describe the defect edge morphology on the evolution between the rolling element and the defect edge contact stiffness and vibration response characteristics of faults based on innovation of the rolling bearing defect dynamics model, laid the foundation for the modeling of rolling bearing local defect edge morphology evolution of stochastic dynamics.
Considering the rolling effect, between the bearing outer ring and bearing seat elastic interface, the interface of the elastic shaft rolling bearing - bearing system of internal excitation vibration dynamics model, overcomes the disadvantages of rigid interface shaft rolling bearing housing system internal excitation vibration transmission dynamics model can not accurately describe the bearing internal excitation caused by the bearing outer ring and bearing seat vibration response difference between features and shortcomings, can not explain the transmission mechanism between the bearing and the bearing internal vibration vibration, bearing vibration of internal excitation along the shaft - bearing - bearing system of elastic interface transfer law, according to the experiment result and table frame comparative analysis, verify the correctness of the model.

【学位授予单位】：重庆大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TH133.33;TH165.3

【参考文献】