平行轴系—转子系统动态特性分析

发布时间：2018-10-10 15:04

【摘要】：随着旋转机械转速不断增加、性能不断提高,转子系统的振动特性越来越成为人们研究的焦点。含有齿轮传动的转子系统获得了广泛的应用,并已成为转子中重要的一个研究领域。在大型旋转机械中,转子系统是其中最为关键的部件,对转子轴系振动特性的分析一直都是该领域研究的必要问题之一。国内外的研究表明,对于耦合系统弯扭特性的研究还不是很透彻,有待于进一步研究,对这一问题的研究成果将对弯扭耦合振动故障的判别具有指导意义。本文主要研究内容如下：首先介绍了现有转子系统动力特性的常用计算方法,建立了斜齿轮的动力学模型,并简单介绍了有限元的基本理论基础。根据有限元法的基本划分原理,利用MATLAB的强大绘图功能,通过编程,实现了单轴和多轴单元划分的二维直观图,并标记出质量点的位置以及支承的位置,多轴的单元图还标记出了相啮合两轴的啮合位置。其次,对某转子系统进行了详细的模态分析,研究了其固有特性的变化,得出了耦合系统中出现的新频率以及新频率的变化特征；并研究了啮合刚度以及支承刚度对耦合系统固有频率的影响。在上述分析基础上,对系统进行不平衡响应分析,得到了系统在不同加载方式下的振动响应情况,并对系统啮合力的变化进行了比较详细的分析,得到了系统啮合力随速度、传递误差以及不平衡量变化的变化规律。分析表明,传递误差和速度对系统的啮合力影响较大,传递误差并非越小越好,因此齿轮系统设计时要做好传递误差的优化工作；不平衡量的变化对系统啮合力的影响相对较小,正常工作条件下,不平衡量越小越好。最后,对系统的启机和停机特性进行了分析,分别分析了系统在定加速度和变加速度的启机和停机特性。研究表明,加速度的选取对启停机过程有着重要的影响,选择适当的启动及停机加速度,不仅可以越过某些临界转速,还可以略微减小振动的幅值,从而延长设备的使用寿命。此外,研究还表明,启停机产生振幅的时问所对应的频率均与之前章节中的频率相吻合,表明这部分分析在理论上是合理的。
[Abstract]:With the increase of rotating speed and performance of rotating machinery, the vibration characteristics of rotor system become the focus of research. Rotor system with gear transmission has been widely used and has become an important research field in rotor. In large rotating machinery, rotor system is the most important component, and the analysis of vibration characteristics of rotor shafting is always one of the necessary problems in this field. The research at home and abroad shows that the study on the bending and torsional characteristics of coupled systems is not very thorough and needs to be further studied. The research results of this problem will be of guiding significance for the identification of the coupled bending and torsional vibration faults. The main contents of this paper are as follows: firstly, the commonly used calculation methods of dynamic characteristics of rotor system are introduced, the dynamic model of helical gear is established, and the basic theoretical basis of finite element method is briefly introduced. According to the basic partition principle of finite element method, by using the powerful drawing function of MATLAB, the two-dimensional visual diagram of uniaxial and multi-axis element partition is realized by programming, and the position of mass point and the position of support are marked out. The multi-axis cell diagram also marks the meshing position of the two-axis meshing. Secondly, the modal analysis of a rotor system is carried out in detail, the change of its inherent characteristics is studied, and the new frequency change characteristics of the coupling system are obtained. The influence of meshing stiffness and supporting stiffness on the natural frequency of coupling system is studied. On the basis of the above analysis, the unbalanced response of the system is analyzed, and the vibration response of the system under different loading modes is obtained. The variation of the meshing force of the system is analyzed in detail, and the meshing force of the system with the velocity is obtained. The law of variation of transfer error and unbalance. The analysis shows that the transmission error and speed have a great influence on the meshing force of the system, and the smaller the transmission error is, the better, so the transmission error optimization should be done well in the design of the gear system. The influence of the unbalance on the meshing force of the system is relatively small. Under normal working conditions, the smaller the unbalance is, the better. Finally, the startup and shutdown characteristics of the system are analyzed, and the startup and shutdown characteristics of the system at constant acceleration and variable acceleration are analyzed respectively. The results show that the selection of acceleration has an important effect on the starting and stopping process. Choosing proper starting and stopping acceleration can not only cross some critical speeds, but also slightly reduce the amplitude of vibration, thus prolonging the service life of the equipment. In addition, it is also shown that the frequency corresponding to the time question of starting and stopping amplitude is consistent with the frequency in the previous chapter, which indicates that this part of the analysis is reasonable in theory.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH113.1

【相似文献】