滚珠丝杆进给系统的多自由度柔体建模研究

Flexible Body and Multi Degree of Freedom Modeling of Ball Screw Feeding System

考虑滚珠丝杠进给系统的机电耦合特性,对系统结构进行分块细化,降低系统的耦合复杂度,提出了丝杠进给系统的分-总式建模方法。将滚珠丝杆系统作多自由度柔体处理,综合考虑系统的弯曲、扭转及沿丝杠轴向的变形,基于动力学理论,采用瞬时变分法,推导出滚珠丝杠进给系统动力学模型,分析得出基于系统结构柔性影响与丝杠轴弯曲剪切综合变形而引起的耦合影响,不同于以往滚珠丝杠进给系统集中质量模型(混合模型)下各向振动之间的耦合影响及振动方程。通过振动实验,借助主分量分析法验证了所建立的动力学模型的正确性,为后续的丝杠进给驱动系统的动力学分析提供研究依据。

Considering the electromechanical coupling characteristics of a ball screw feed system into account,the system structure is subdivided to several fine parts. By reducing the complexity and coupling degree of feed system,a block-lumped modeling method for the screw feed system is proposed. Based on the dynamic theory,the dynamic model of the ball screw feed system was established by using the instantaneous variation method,and the ball screw system was processed by the multi-degree-of-freedom（ DOF） flexible system. The bending,torsion and axial deformation were also taken into account. The coupling effect of the flexible bodies and the bending deformation of the screw shaft were analyzed and deduced,which was different from the coupling effect between the vibration of the concentrated mass model（ or mixed model） of the ball screw feed system and equations. Finally,the validity of the established dynamic model is verified by the vibration experiment and principal component analysis（ PCA）,which provides the study basis for the dynamic analysis of the screw feed drive system.