柴油机连杆小头衬套磨损仿真及改进
刘飞1,唐靖1,白书战2
1.重庆潍柴发动机有限公司,重庆 402260; 2.山东大学 能源与动力工程学院,山东 济南 250061
摘要:为解决某中速柴油机出现的连杆小头衬套异常磨损故障,建立多体动力学模型,进行连杆实际工作过程仿真,分析衬套异常磨损原因,提出改进方案,并对改进方案进行仿真与试验验证。仿真分析结果表明,连杆衬套异常磨损的主要原因是油膜总压和粗糙接触压力过大。基于分析结果,将连杆衬套和活塞销之间的接触宽度从56 mm增加到66 mm,增大连杆衬套的承载面,减少油膜总压和粗糙接触压力。改进前、后仿真对比分析表明:衬套的油膜总压降低约50%,粗糙接触压力降低约70%。试验验证结果表明,衬套下部承压面边缘和油孔周围无磨损痕迹。增加衬套与活塞销的接触宽度可以有效减小衬套的油膜总压和粗糙接触压力,避免连杆小头衬套异常磨损。
关键词:连杆小头衬套;磨损;总压;粗糙接触压力
Wear simulation of small end bush for diesel engine connecting rod and its improvement
LIU Fei1, TANG Jing1, BAI Shuzhan2
1. Weichai(Chongqing)Engine Co., Ltd., Chongqing 402260, China;
2. School of Energy and Power Engineering,Shandong University,Jinan 250061, China
Abstract:In order to solve the abnormal wear failure of the small end bushing of the connecting rod of a medium speed diesel engine, a multibody dynamics model is established to simulate the actual working process of the connecting rod, analyze the causes of the abnormal wear of the bushing, and propose an improvement. The improvement is verified by simulation and experiment. The simulation results show that the excessive total oil film pressure and rough contact pressure are the main reasons for the abnormal wear of the connecting rod bushing. Based on the analysis results, the contact width between the connecting rod bushing and the piston pin is increased from 56 mm to 66 mm, which increases the bearing surface of the connecting rod bushing and reduce the total oil film pressure and rough contact pressure. The simulation results before and after the improvement show that the total oil film pressure drop of the bushing is about 50% , and the rough contact pressure is about 70% lower. The test results show that there is no wear trace on the edge of the lower pressure bearing surface of the bushing and around the oil hole. Increasing the contact width between the bushing and the piston pin can effectively reduce the total oil film pressure and rough contact pressure of the bushing, and avoid abnormal wear of the small end bushing of the connecting rod.
Keywords:small end bush of connecting rod;wear;total pressure;rough contact pressure