柴油机轴瓦抱轴故障分析

Failure Analysis of Diesel Engine Bearing Bushing

某型巡逻船用柴油机在试航过程中出现自动停车故障,停车后无法盘车,检查发后现轴瓦抱轴,对引起柴油机轴瓦抱轴可能原因采用故障树进行逐一分析,对可能引起故障因素进行排查,找出了引起故障的原因主要为:柴油机使用CF-415W-40机油,属于多级油。多级油是在低粘度基础油中加入粘度指数改进剂等调合而成,粘度指数改进剂属于高分子聚合物,在高剪切条件下可能断裂,高分子聚合物断裂后是不可逆的,导致粘度很快降低,机油承载能力下降。另外在隔振器安装支脚压缩高度超差及其他外部原因多重因素下,油膜不能起到良好的润滑作用,引发轴瓦损坏故障。

A certain type of patrol Reciprocating diesel engines was found to have an automatic stop failure during the course of the trial run.After stopping,it was unable to turn the vehicle around.After checking and discovering the bearing bushing,the possible causes of bearing bushing were analyzed one by one by using a fault tree,the possible causes of the failure were found out through investigation.The main causes were as follows:the diesel engine carrying CF-415 W-40 belongs to multi-grade oil.The multi-grade oil is made by blending low viscosity base oil with viscosity index improver,which belongs to polymer and may break under high shear condition,resulting in a rapid reduction in viscosity,oil bearing capacity decline.In addition,the oil film can not play a good role in lubrication and lead to the failure of bearing bush due to excessive compression height and other external factors.