【作者】 钱恩；

【导师】 秦大同；

【作者基本信息】 重庆大学 ， 机械设计及理论， 2009， 硕士

【摘要】 随着齿轮传动系统转速不断增加、性能不断提高,对于高速齿轮传动转子系统的动力特性研究越来越成为人们研究的焦点。由于齿轮的啮合作用,使得各转子之间的弯曲振动和扭转振动相互耦合,因而齿轮转子系统的动力学特性不能仅从单个转子来考察,为此必须建立系统的弯扭耦合系统模型来分析其动力学特性。论文依托国家科技支撑项目计划《高速、重载齿轮传动系统共性关键技术》,以高速重载燃气轮机齿轮传动转子系统为研究对象,结合现有的对简单转子系统动力特性的研究方法,对齿轮转子的动力学特性包括临界转速及不平衡响应进行研究,为燃气轮机齿轮箱的设计提供参考。论文首先简单介绍了转子振动问题的研究现状和当前面临的主要问题以及国内外对此问题的解决方法。总结了计算转子系统临界转速及振动模态的传递矩阵法,对简单转子系统弯振和扭振分析问题做了细致的研究,列举了几种典型单元的传递矩阵;并对滑动轴承支承转子的动力学特性的计算方法进行了研究。讨论了滑动轴承动力特性及油膜动力特性系数的确定,并就转子振动量的复数表示进行了深入研究,对转子系统的运动形态进行了分析,推导了各向异性支承转子典型单元的传递矩阵。应用整体传递矩阵法的基本理论对多平行轴耦合转子系统进行了建模及分析,推出了其整体传递矩阵。针对高速、重载燃气轮机齿轮转子系统,讨论并计算其轴承阻尼,刚度,齿轮啮合刚度,啮合阻尼以及齿轮转子系统各相关参数,导出耦合刚度阵,阻尼阵,运用传递矩阵法建立单轴转子的弯振模型及齿轮耦合转子系统的弯扭耦合振动模型,并对其固有特性进行了分析计算。结果表明,由于齿轮的啮合作用,使得转子系统的弯曲振动和扭转振动耦合在一起,并派生出一些新的临界转速及相应模态,因此在系统设计时需特别注意齿轮传动对这些模态的影响。最后,本文对齿轮转子系统的不平衡量响应进行了分析,结果表明,由于齿轮耦合作用,系统某一转子上的激振力将传递给其他转子,特别是高速轴上的不平衡量将引起转子系统的剧烈振动,因此要注意提高转子尤其是高速转子的动平衡精度,降低不平衡激励,以提高系统的动态品质。更多还原

【Abstract】 With the increase of rotational speed of gear-rotors and the improvement of its performance, the study of the dynamic characteristic of the gear-rotor system has been becoming a research focus. Because of the gears meshing, bending vibration and torsional vibration of rotors are coupling, so we can’t analyze the dynamic characteristic of rotors system with only one rotor. In order to analyze the dynamic characteristic of gear-rotor system, the lateral-torsional coupling vibration modal must be set up.Papers rely on the support of national science and technology project“the Common Key Technology of High-speed, Heavy-duty Gear Drive System”, combined with the currently research method of simple rotor dynamic characteristics, to study dynamic characteristic of High-speed, Heavy-duty gas turbine gear-rotor system, which including the critical speed and unbalance response. It has provided reference for the design of gas turbine gear box.Papers briefly introduced the present research of rotor dynamics, and presented the problem facing in domestic research along with the solutions to that problem have realized. Then we described the transfer matrix method for calculating the critical speed and their vibration modal of the rotor system. The bending and torsional vibration issues of simple rotor were studied separately, many transfer matrixes of several typical units were appended. Furthermore, the method to calculate the characteristic of the rotor which supported by sliding bearing was studied. We discussed the method for calculating the dynamic coefficient of sliding bearing along with its dynamic characteristics, and the plural value of the vibration characteristics was intensively researched, as well as the vibration modal. Then the transfer matrix of rotor supported by sliding bearings was deduced. In succession, the paper gave an overview of basic theory of the whole transmission matrix, with this method the whole transmission matrix of multi-axis parallel coupling rotor system was built.Basing on the topic of high speed and heavy duty gas turbine gear-rotor system, the bearing damping, stiffness, gear meshing stiffness, meshing damping, the coupling stiffness and the related parameters of gear-rotor system were studied and discussed,. According to the work above, the coupled stiffness and damping matrix were deduced. Then using the transfer matrix method, the bending vibration modal and the lateral-torsional coupling vibration model of gear-rotor system was established. Moreover, its inherent characteristics were analyzed and calculated. The result shows that, because of the gear meshing, making bending vibration of rotor system coupled with the torsional vibration, which derived some new critical speed and the corresponding mode. Therefore, we should pay particular attention to the impact made by gear transmission when designed the system.Finally, papers analyzed the unbalance response of the gear-rotor system. We can conclude, as the result of the gear coupling effect, when we imposed the exciting force on one rotor, the vibration will be transfer to the others which link together with the running shaft through gear meshing, especially high-speed shaft unbalance will cause intense vibration. Therefore, we should pay attention to improve the precision of dynamic balance of rotor, and reduce the unbalance quantity to improve the dynamic performance of system.更多还原