某型柴油机曲轴裂纹故障原因分析

Reasons Analysis for Crankshaft Crack on a Certain Type of Engine

针对某型柴油机故障情况,检查曲轴、活塞、连杆大端瓦故障分析讨论,可以得出柴油机故障原因如下:曲轴裂纹属扭转疲劳裂纹,其形成原因主要是扭振附加应力超限和工作载荷过载;曲轴裂纹影响轴瓦油膜建立并刮瓦,逐渐导致连杆大端瓦失效;连杆大端瓦的损坏,影响活塞冷却和活塞运行姿态,导致活塞故障。

This text analyzes and discusses the faults of crankshaft, piston and con-rod big end shell according to the inspection of running condition on a certain type of engine. The analysis results show that the cause of engine fault is as following： crankshaft crack is torsional fatigue crack, which is mainly caused by overrunning of additional stress of torsional vibration and working overload; crankshaft crack affects the oil film formation to scrape shell, resulting con-rod big end shell loses effectiveness; cooling and working attitude of piston is affected by damage of con-rod big end shell, resulting in piston fault.