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
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 multi body 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
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