铣床主轴系统刚柔耦合多体动力学建模与仿真分析

【作者】 姚廷强；

【导师】 迟毅林；

【作者基本信息】 昆明理工大学 ， 机械电子工程， 2007， 硕士

【摘要】 高速、高效、载荷／质量比大、精密复杂的机械系统已成为研发、生产现代机床产品的主流。高速加工或准高速加工要求机床系统具有很好的动态特性，以满足现代生产力、精度和可靠性的要求。在实际工程中，机床系统的加工性能在很大程度上取决于主轴系统的动态响应特性和可靠性。本文结合云南省省院省校合作项目“共建昆明铣床厂产品开发技术创新中心”，以有限元法和刚柔耦合多体系统动力学方法为基础，提出基于修正的C-B模态集成耦合法的动力学仿真模型，预估刚柔耦合多体主轴系统的动态响应的分析方法。该方法可以有效地解决考虑多动态参数激励的主轴系统的动态响应问题，仿真结果为机床主轴系统的动态设计和分析研究主轴系统的动态响应特性提供重要的参考数据和理论依据。本文在铣床主轴系统的协同设计与仿真的数据交换、主轴多体系统的刚柔耦合动力学建模、角接触球轴承3D接触动力分析、主轴—轴承部件耦合固有特性和动力响应分析、刚柔耦合多体主轴系统的动力分析等几个方面进行了较全面、系统、深入的数值分析和应用研究。基于Hertz接触理论，建立了角接触球轴承的接触动力学模型，提出考虑摩擦力、离心力和陀螺力矩作用的角接触球轴承3D接触动力学分析的方法；利用修正的Craig-Bampton模态集成耦合法，建立主轴—轴承部件耦合的动力分析模型，进行固有特性分析和受迫振动分析。利用文献[91]的模态试验数据验证了分析模型和计算结果的正确性。从总体上看，刚柔耦合多体主轴系统的动态响应具有周期性和稳定性，说明其具有较好的动态性能。分析出铣床主轴4000rpm的转速频率不会激起主轴系统的共振响应；在同转速条件下，刀具为6齿端铣刀时的切削力激励频率并不在主轴系统的安全频率范围。垂直主轴功率实验工况Ⅰ的切削深度为2／3最大值和切削深度为最大值两种边界条件下，柔性主轴最大径向振动位移值均在结点1处的刀具端。该位移值相对较大，具有较强的周期性，说明主轴系统具有较好的动态性能。主轴转速为4000rpm，柔性主轴结点1处的刀具端径向振动的位移值比柔性主轴—轴承部件的径向振动位移值大。刚柔耦合多体主轴系统的振动速度和加速度响应特性，表明柔性主轴具有较大的振动速度和加速度，尤其是冲击加速度，因此，铣床并不适合在4000rpm下，使用6齿刀具进行实际的零件加工。更多还原

【Abstract】 Nowadays the mainstream of research and manufacture of machine tools is mechanical system which has high speed, effect, rate of load and mass, precise and complex properties. From the desire of modern productivity, precision and reliability, High or simi-high Speed Machining requires mechanical systems with high dynamic properties. However, the machining capability of mechanical systems almost depends on the dynamic response properties and reliability of Spindle systems in many engineerings.Based on the co-project of "Establishing Technique Center of Kunming Mill Machine Factory", accomplished by Yunnan Province and Kunming University of Science and Technology, the Spindle system dynamic model was analyzed according to Finite Element Method, Multi-bodies Flexible System Dynamics and the modified modal integral coupling method of Craig-Bampton. A numerical method on forecasting the dynamic response of multi-bodies flexible spindle system effectively was given by this dissertation. The new method can effectively deal with the dynamic response of spindle system with multi-dynamic parameters excitation and the simulation results provide basic data for Spindle system dynamic design and valuable theoretical basis for further research on dynamic response of Spindle system.The numerical analysis and its application were comprehensively and systematically studied. It’s about co-design and simulation of Spindle system of milling machine, modeling the rigid and flexible coupling Spindle system, dynamic contact analysis of angular contact ball bearing, analysis on the inherent characteristics and dynamic response of spindle and bearing coupling model, dynamic analysis on multi-bodies flexible Spindle system.The contact dynamic model and numerical method of angular contact ball bearing was proposed on the basis of the theory of Hertz Contact Dynamic with the effect of speed, axis and radial preload, friction and centrifugal force. The coupled dynamic model of spindle and bearing was proposed on the basis of the modified modal integral coupling method of Craig-Bampton. Accomplish analysis on the inherent characteristics and dynamic response and validate the correctness of the analysis model and results with the data of EAM in the literature [91]. As a whole, the dynamic response of multi-bodies flexible Spindle system takes on periodicity and stability, the results indicate that it has preferable dynamic properties.From the results, we know the speed frequency is safe from triggering off the resonance of Spindle system, but the frequency of cutting force with six tooth-end milling cutter is out of the safe frequency range of Spindle system. Under two special conditions about the power experiment of the vertical Spindle, the cutting depth are 2/3 of max and max, the max displacements of radial vibration of the flexible spindle are both at the milling cutter, NODE ONE. The displacements is relatively big and having strong circles. It supports the Spindle has goog properities. Under the speed 4000rpm, the max displacement of radial vibration of the flexible spindle is at the milling cutter, NODE ONE. It’s more than that of flexible spindle and bearing model. However, the velocity and acceleration of the Spindle vibration are much bigger and support this miling machine may not be suitable for working at the speed 4000rpm using six teeth cutting.更多还原