基于球轴承刚度计算的电主轴结构分析与优化

发布时间：2018-06-30 20:59

本文选题：电主轴 + 角接触球轴承　；参考：《华中科技大学》2011年硕士论文

【摘要】：电主轴技术是随着高速磨削等现代化制造技术以及高速CNC加工中心的发展和需求而发展起来的,随着电主轴转速和功率的不断提高,高速电主轴的应用越来越广泛。高速电主轴的工作转速常接近于转子系统的一阶临界转速,因此,需要对电主轴的结构,固有频率和临界转速等动态性能进行分析计算。本文利用球轴承分析计算的基本理论与方法,在分析角接触球轴承内部静力学及动力学状态和进行静、动刚度计算的基础上,应用有限元分析软件ANSYS建立电主轴球轴承—转子系统的参数化有限元模型,以提高电主轴静刚度为优化目标,对电主轴结构进行优化分析,使电主轴结构更紧凑,固有频率及临界转速更高,振动特性更好,尤其是其在临界转速内的振动特性。本文具体工作如下: 以Hertz弹性接触理论为基础,对球轴承的几何关系,接触应力变形及载荷分布进行介绍。以角接触球轴承为研究对象,分析其在径向、轴向、轴向预紧及联合载荷作用下的受力变形情况,得到其静刚度。并进一步考虑了角接触球轴承高速旋转时产生的离心力、陀螺力矩及其内部运动时产生的摩擦力,对高速时角接触球轴承内部的动力学状态与动刚度进行分析计算。利用角接触球轴承刚度分析的结果,在有限元软件ANSYS中建立电主轴球轴承—转子系统的参数化有限元模型,并以提高电主轴静刚度为优化目标,对电主轴支承跨距和电机安装位置进行优化分析计算,使电主轴的静刚度提高了7.81%,并对优化前后的电主轴系统进行模态分析,发现其频率增大,其中一阶固有频率增大了1.93%。最后对电主轴进行三维模态分析,更直观的展现电主轴的前五阶振型。
[Abstract]:Motorized spindle technology is developed with the development and demand of modern manufacturing technology such as high-speed grinding and high-speed CNC machining center. With the increasing speed and power of motorized spindle, the application of high-speed motorized spindle is becoming more and more extensive. The working speed of the high speed motorized spindle is usually close to the first order critical speed of the rotor system. Therefore, it is necessary to analyze and calculate the dynamic performance of the motorized spindle, such as its structure, natural frequency and critical speed. Based on the basic theory and method of ball bearing analysis and calculation, the static and dynamic state of angular contact ball bearing and the calculation of static and dynamic stiffness are analyzed in this paper. The finite element analysis software ANSYS is used to establish the parameterized finite element model of the motorized spindle ball bearing rotor system. With the aim of improving the static stiffness of the motorized spindle, the structure of the motorized spindle is optimized and analyzed so as to make the motorized spindle structure more compact. The natural frequency and critical speed are higher, and the vibration characteristics are better, especially in the critical speed. The main work of this paper is as follows: based on Hertz's elastic contact theory, the geometric relationship, contact stress deformation and load distribution of ball bearings are introduced. The static stiffness of angular contact ball bearing is obtained by analyzing its deformation under radial, axial preloading and combined loads. The centrifugal force, the gyroscopic moment and the internal friction produced by the angular contact ball bearing are further considered. The dynamic state and dynamic stiffness of the angular contact ball bearing at high speed are analyzed and calculated. Based on the results of stiffness analysis of angular contact ball bearings, the parametric finite element model of motor spindle ball bearing-rotor system is established in the finite element software ANSYS, and the optimization goal is to improve the static stiffness of motor spindle. The optimum analysis and calculation of the span of the motorized spindle and the installation position of the motor make the static stiffness of the motorized spindle increase by 7.81%. The modal analysis of the motorized spindle system before and after optimization shows that the frequency increases, and the first natural frequency increases by 1.93%. Finally, the three-dimensional modal analysis of the motorized spindle is carried out to show the first five modes of the motorized spindle more intuitively.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH133.3

【引证文献】