含间隙转动副冗余约束机构的动力学特性  

Dynamic Performance Analysis for Over-Constrained Mechanisms with Multiple Revolute Clearance Joints

作　　者：张健 余海东[2] 李琳[1] 王皓[1,2] 

机构地区：[1]上海交通大学机械系统与振动国家重点实验室,上海200240 [2]上海交通大学上海市复杂薄板产品数字化制造重点实验室,上海200240

出　　处：《机械设计与研究》2018年第1期76-81,86,共7页Machine Design And Research

基　　金：国家自然科学基金(51275292);国家重点基础研究发展规划(973)(2013CB035403)资助项目

摘　　要：运动副间隙将引起机构运动精度降低，产生振动与噪声，甚至导致机构失效。基于单个平面间隙全文的存在将导致系统增加两个自由度，对含间隙冗余约束平行四边形机构实际自由度进行分析，采用间隙铰接触碰撞模型和拉格朗日方法建立该机构动力学模型，分析了间隙值和间隙位置对机构动力学特性的影响规律。结果表明，随着转动副间隙值的增加，机构运动精度降低，同时平衡力矩的冲击特征减弱；不同位置的转动副两元素接触频率存在差异，因此间隙位置对机构振动存在影响。通过研究含间隙转动副冗余约束机构动力学特性，可以为机构运动副元素尺寸设计及加工过程提供理论指导。The presence of clearance joints may cause the deterioration of the kinematic accuracy, vibration, noise and even fatigue failure of the system. The number of DOFs is more than the number of independent coordinates in the over-constrained mechanism with multiple clearance joints since two degrees of freedom are introduced when a clearance joint is considered, and the difference is the number of redundant constraints. A common angular coordinate in the clearance of the redundant constraint is eliminated to revise the DOFs and overcome difficulties in dynamic modeling and simulation. The equations of motion for the system is established based on the Impact Ring Model and Lagrange method to study dynamic performance of the planar mechanism. The effects of clearance size and the location of clearance joint on the characteristics of kinematic accuracy, velocity, acceleration, counterbalance moment, and the impact frequency are discussed. The results show that smaller clearance combinations could lead to high kinematic accuracy, obvious vibrations and impact phenomenon. In addition, the components of the revolute joints under smaller clearances experience contact-impact phenomenon more frequently. From the main results obtained in this study, the dynamic model may provide a guidance to the dimension design and machining process of the joint components.

关 键 词：冗余约束机构 转动副间隙 动力学分析 运动精度 冲击振动 

分 类 号：TH113.22[机械工程—机械设计及理论]