考虑随机圆度误差的滑动轴承转子系统非线性动力学研究

发布时间：2018-10-20 18:20

【摘要】：作为旋转机械的重要组成部件,滑动轴承运行过程的动力学特性及稳定性直接影响着旋转机械的运行安全。滑动轴承转子系统的圆度误差由于制造精度的限制往往不可避免,而它的存在直接影响着滑动轴承油膜的形状,进而对滑动轴承动力学特性及稳定性产生明显影响。现有研究方法常采用椭圆等特定形状描述轴颈或轴瓦的圆度误差,在探究对系统动力学特性的影响时也仅针轴颈圆度误差展开,这与工程实际有较大差距,为深入刻画随机性圆度误差对滑动轴承系统的动力学特性的影响,本论文开展了考虑随机圆度误差的滑动轴承转子系统非线性动力学的研究。基于普通滑动轴承转子系统研究的基础上,本文从圆度误差的随机性入手,应用数理统计方法描述随机分布的轴承圆度误差,并将其引入到转子系统动力学分析和稳定性研究中,基于6Sigma质量管理体系中质量特性要求,建立服从Gauss分布的带有随机圆度误差的滑动转子轴承系统统计学分析模型。文中应用Sommerfeld Number正态性,判断了所建的动力学研究模型的正确性。本文基于非线性动力学理论,分析了轴瓦、轴颈的圆度误差以及二者耦合作用时,随机圆度误差对滑动轴承转子系统包括稳定性、能量损失等在内的动力学特性的影响。结果表明:轴颈圆度误差对系统的稳定性的影响随轴颈圆度误差的增加而更加稳定,并大于轴瓦圆度误差对转子系统的影响。为了验证理论的正确性,本文研究中借助专门搭建的转子试验台,对滑动轴承系统的临界转速,轴心轨迹以及频谱等进行实验验证,同时对比相关文献理论,验证了本文分析结果的正确性。本论文的研究揭示了随机圆度误差对系统的动力学特性的影响规律,使预测滑动轴承系统运行性能成为可能,并为滑动轴承的公差设计及系统诊断提供理论依据,为研制低成本高性能滑动轴承转子系统奠定了理论基础。
[Abstract]:As an important component of rotating machinery, the dynamic characteristics and stability of sliding bearings directly affect the running safety of rotating machinery. The roundness error of sliding bearing rotor system is often unavoidable due to the limitation of manufacturing accuracy, and its existence directly affects the shape of oil film of sliding bearing, and then has a significant effect on the dynamic characteristics and stability of sliding bearing. The current research methods often use ellipse and other specific shapes to describe the roundness error of the journal or the bearing, and only expand the roundness error of the needle journal when exploring the influence on the dynamic characteristics of the system, which is quite different from the engineering practice. In order to describe the effect of random roundness error on the dynamic characteristics of sliding bearing system, the nonlinear dynamics of journal bearing rotor system considering random roundness error is studied in this paper. Based on the research of ordinary sliding bearing rotor system, this paper starts with the randomness of roundness error, and applies mathematical statistics method to describe the random distribution of bearing roundness error. Based on the quality characteristic requirement of 6Sigma quality management system, a statistical analysis model of sliding rotor bearing system with random roundness error is established based on Gauss distribution. Sommerfeld Number normality is used to judge the correctness of the established kinetic model. Based on the theory of nonlinear dynamics, this paper analyzes the influence of the roundness error of bearing and journal and the influence of random roundness error on the dynamic characteristics of sliding bearing rotor system, including stability, energy loss, etc. The results show that the influence of journal roundness error on system stability is more stable with the increase of journal roundness error, and is greater than that of bearing roundness error on rotor system. In order to verify the correctness of the theory, the critical speed, axis track and frequency spectrum of the sliding bearing system are experimentally verified by the rotor test rig built in this paper. At the same time, the relevant literature theory is compared. The correctness of the analysis results is verified. The research in this paper reveals the influence of random roundness error on the dynamic characteristics of the system, makes it possible to predict the performance of sliding bearing system, and provides a theoretical basis for the tolerance design and system diagnosis of sliding bearing. It lays a theoretical foundation for the development of low cost and high performance sliding bearing rotor system.
【学位授予单位】：广西科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TH133.31

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