第9期 2016年9月
组合机床与自动化加工技术
Modular Machine Tool & Automatic Manufacturing Technique
文章编号：10012265(2016)09000504
DO1:10. 13462/j. cnki. mmtamt.2016.09.002
双丝杠驱动直线导轨进给单元轴向
刚度与有限元模态分析
许向荣，宋现春，鹿群鹏，姜洪奎
（山东建筑大学机电工程学院，济南250101）
No.9 Sep.2016
摘要：双丝杠驱动直线导轨进给单元具有良好的抗振性、高系统刚度以及快速系统响应性等优点，能够有效地抑制数控机床在高速和高加减速情况下产生的振动，因此其在高速和高精类数控机床中的应用日益广泛。基于动力学相关理论，对双丝杠驱动直线导轨进给单元进行了轴向刚度建模，并基于Hertz接触理论推导了各部分的度计算公式；以实例计算获得了其各部分刚度的比例关系，找到了影响双丝杠驱动直线导轨进给单元的主要影响因素，获得了螺母位置与进给单元轴向刚度的关系曲线；对采用两端固定支承方式的双丝杠驱动直线导轨进给单元进行了有限元模态分析，得到了螺母处于不同位置处的固有频率和模态振型。结果表明：螺母位置是双丝杠驱动直线导轨进给单元轴
处进行加工。
关键词：双丝杠驱动；进给单元；刚度模型；模态分析；固有频率；振型
中图分类号：TH132;TG659
文献标识码：A
Axial Stiffness and Finite Element Modal Analysis of Dual Ball
Screw Driving Linear Guide Feed Unit
XU Xiang-rong,SONG Xian-chun,LU Qun-peng,JIANG Hong-kui
(School of Mechanical and Electrical Engineering, Shandong Jianzhu University , Jinan 250101,China) Abstract : Dual ball screw driving linear feed unit has good vibration resistance, high stiffness and fast sys tem response, etc. , can effectively suppress vibration of CNC machine tools generated in the case of high speed and high acceleration and deceleration, so it is used widely in the high-speed and high-precision CNC machine tools. This paper is focused on the completion of axial stiffness model of dual ball screw driving
linear guide feed unit based on dynamics theory; stiffness
ferent proportion of each part is
calculatedbas
calculation equation of each part is deduced. Dif-example; the main influencing factor of axial
stiffness of dual ball screw driving linear guide feed unit is found; the relationship curve is plotted between nut position and axial stiffness of feed unit; the finite element modal analysis is carried on, the main natural frequencies and vibration shapes of feed unit are obtained when nut is located at different positions. The re-sults show that nut position is the main influencing factor on the axial stiffness of feed unit; the natural fre quencies at two fixed ends are higher than those at middle position, so the natural frequencies of feed unit at middle position decrease to the lowest. As a result, it is necessary not to make machines working at middle position.
Key words: dual ball screw driving; feed unit; stiffness model; modal analysis; natural frequencies; vibra tion mode
0
引言
由于双丝杠驱动进给系统可以提高系统刚度、降低振动，进而提高加工精度，因而日益成为数控机床、
加工中心研究领域的一个热点。
Hiramoto等设计了工作台和主轴均采用重心驱动的机床模型：建立了实际的双驱动进给系统的实验模型，并通过实验发现重心驱动进给系统可以明显地减小
收稿日期：2015-1221
+基金项目：国家自然科学基金项目（51205235）：山东建筑大学校内博士基金项目（XNBS1246）
作者简介：许向荣（1978一），女，山西曲沃人，山东建筑大学副教授，博士，研究方向为机电系统精密测控及系统动力学，（E-mail)xt7875@163.com 万方数据