【作者】 赵鹏；

【导师】 王晓光；

【作者基本信息】 武汉理工大学 ， 机械制造及其自动化， 2005， 硕士

【摘要】 磁力轴承作为目前可应用于工程实际、且能够实施主动控制的支承部件之一,具有一般传统轴承和支承技术所无法比拟的优点,目前己在各个领域的高速旋转机械中开始应用。虽然磁力轴承的基础理论已经取得了丰硕的成果,也有成功实例,但样机在实验时实际稳定转速达不到设计工作转速,且在高速运行状态下稳定性差等问题,已经严重制约了该技术的推广应用。磁悬浮转子系统的动力学特性就成为其进入应用基础研究阶段后,研究者普遍关注的诸多实际问题之一。本文的主要工作内容就是针对这些问题和现象,解决在磁力轴承支承条件下高速转子系统的临界转速分析和计算问题。 本文首先引述和概括了传统转子动力学的研究方法及有关理论,并以此作为磁悬浮轴承转子动力学的研究基础,接着,以单自由度等效刚度阻尼系数计算方法为基础,详细分析了完整的磁力轴承动力特性系数的计算方法。然后,本文分别对磁悬浮刚性转子系统和磁悬浮柔性转子系统进行了数学建模,并用Riccati传递矩阵法结合磁力轴承的有关特点,建立了磁悬浮柔性转子系统的动力学计算和分析方法。最后,对一实际的磁悬浮柔性转子系统进行了理论计算和实验验证。 通过本文的研究,得到以下主要结论:磁力轴承的动力特性系数可以由八个等效的刚度阻尼系数来表示,这八个等效的动力特性系数和轴承的结构参数和控制器的控制参数密切相关;磁悬浮转子系统的低阶临界转速主要由磁力轴承支承刚度决定,其大小与磁力轴承和控制器的参数有关,可以通过改变磁力轴承的结构参数和控制器的控制参数来改变低阶临界转速的值;而高阶临界转速受磁力轴承支承刚度的影响很小,很难通过改变支承刚度来改变它们的大小,只能通过改变转子的几何尺寸或结构来调整。更多还原

【Abstract】 As one of the supporting components, which can be controlled actively, active magnetic bearing (AMB) has been widely used in many machines with high rotation speed in all kinds of field because of its high performances beyond other traditional bearings. The basic research of the AMB has been achieved, but there are still many problems to be solved before putting them into industrial applications. One of them is bearing-rotor system dynamics and its stability. This paper will deal with these problems, and mainly focus on the critical speeds of the high speed rotating machinery supported AMB.First, some useful methods and theories in traditional bearing-rotor dynamics are summarized as the basis of study on dynamics of active magnetic bearing-rotor system. Next, basic on the analysis and calculation formulas of stiffness and dampness of one-degree-of-freedom, calculation formulas of stiffness and dampness of five-degree-of-freedom is given. Secondly, the mathematical model and mechanic models have been established using traditional dynamics combined with the characteristics of AMB. Then, by considering the characteristics of AMB and adapting the traditional Riccati transfer matrix method to active magnetic suspension rotor system, a method is established for calculating and analyzing dynamics. Finally, an actual active magnetic bearing-rotor system is calculated and validated by using above method and experiment.Some conclusions are formed by analyzing the results of the calculations: Like traditional bearings, the dynamic characteristic coefficient can be described by eight equivalent stiffness and dampness coefficients. The stiffness and dampness coefficients relate with not only parameters of bearing itself but those of controller as well and thus stiffness and dampness coefficients can be adjusted by changing those parameters. Low critical speed of magnetic suspension rotor system is mainly determined by bearing structure and parameters of controller on AMB, while high critical speed is mainly affected by rotor structure.更多还原