基于动力学特性的挖掘机工作装置端面摩擦副间隙磨损机理研究

Excavator Working Device Based on Dynamic Characteristics Analysis of Clearance Wear Mechanism of End Face Friction Pair

机械动力装备中常因为作业工况恶劣导致关节端面摩擦副间隙处磨损严重,为了探讨关节端面摩擦副间隙处作业过程中磨损变化行为及作用机理,以某型号挖掘机为例,基于动力学模拟分析两种典型工况下得到动臂关节处动态载荷数据基础上,利用有限元数值模拟技术并修正Archard磨损模型计算得出端面摩擦副间隙处磨损深度与磨损次数的关系,在端面磨损试验机上验证两种工况下关节间隙处耐磨垫片磨损变化过程,在扫描电镜下观察磨损后的表面形貌分析磨损作用机理。结果表明:两种工况下,磨损区域均为环形区域;偏载工况磨损主要与接触应力值大小和偏载角度有关,磨损过程中表面产生锥刺凹坑和交叉犁沟等,磨损机制由疲劳磨损向黏着磨损转化,同时伴随有少量的磨粒磨损;满载启动回转工况磨损主要与接触碰撞程度有关,磨损形式主要为黏着磨损与磨粒磨损。此分析方法对工程机械行业分析其它动力装备关节摩擦副和工程应用具有较好的参考价值。

Mechanical power equipment often because of bad operation condition affecting the face friction pair clearance of wear serious, in order to discuss joint changes in operation in the process of friction pair clearance and wear behavior and mechanism of action, to a certain type excavator as an example, based on dynamics simulation analysis under two kinds of typical working condition of the movable arm joints based on dynamic load data, Using finite element numerical simulation technology and correct Archard wear model calculated friction pair clearance in the relationship between the number of wear depth and wear, in the end wear test machine to verify two joint clearance under the condition of abrasion and gasket change process, and observed under scanning electron microscopy(SEM) analysis of surface topography after wear and wear mechanism. It turns out that the wear areas are annular in both conditions. In off-load condition, the wear is mainly related to the contact stress value and off-load Angle. During the wear process, the surface produces cone-punctured pits and cross furrows, and the wear mechanism changes from fatigue wear to adhesive wear, accompanied by a small amount of abrasive wear. At full load, the wear is mainly related to the degree of contact and collision,and the wear forms are adhesive wear and abrasive wear. This method of analysis has a good reference value for the construction machinery industry to analyze other power equipment joint friction pairs and engineering applications.