挖掘机工作装置关节摩擦副动态接触特性分析

Analysis of Dynamic Contact Characteristics of Joint Friction Pair of Excavator Working Device

挖掘机工作装置关节摩擦副直接关系到挖掘机的作业质量以及产品可靠性。针对挖掘机在使用过程中出现关节摩擦副耳板外翻以及端面磨损严重问题,建立工作装置动力学模型,并基于ADAMS进行了动力学仿真,得到工作装置3个主要承重关节载荷谱数据,同时加以应变片实验验证,确保动力学仿真结果的正确性。在此基础上,基于动力学仿真结果载荷谱数据,应用ANSYS对工作装置的动臂-底座关节进行动态接触特性仿真分析。结果表明:工作装置在挖掘过程启动和结束时候存在较大突变载荷,对耳板产生冲击;接触端面的峰值应力远低于材料许用应力,端面破坏主要是由疲劳破坏造成;接触磨损区域主要集中于一侧端面外边缘处,伴随着相互之间的黏附,端面的磨损由外向内将逐渐延伸。研究结果为挖掘机工作装置关节端面碰撞冲击、磨损分析以及关节接触优化提供依据。

The joint friction pair of excavator working device is directly related to the operation quality and product reliability of excavator.Aiming at the joint friction pair ear plate eversion and end face wear in the use of excavator,the dynamic model for working device is established,and the dynamic simulation is carried out via ADAMS to obtain the load spectrum of three main load-bearing joints of working device.At the same time,it is verified by using the strain gauge experiment to ensure the correctness of dynamic simulation results.Based on the load spectrum of dynamic simulation results,the dynamic contact characteristics of boom base joint of working device are simulated and analyzed by using ANSYS.The results show that the working device has a large sudden load at the start and end of the excavation process,which has an impact on the ear plate,the failure of joint end face is caused by fatigue failure,the contact wear area is mainly concentrated at the outer edge of one end face.With the adhesion between them,the wear of the end face will gradually extend from the outside to the inside.The conclusions provide a basis for the impact,wear analysis and joint contact optimization of the joint end face of the excavator working device.