航空活塞发动机挺杆体异常磨损失效分析

Failure Analysis on Tappet Abnormal Wear in Aviation Piston Engine

某飞行训练机构所属的航空活塞发动机在翻修后首次100 h定检时,连续多次在滑油滤上发现异常金属屑,此情况严重影响飞行安全。进一步分解发动机检查,发现此金属屑均为发动机内部挺杆体与其对偶的凸轮轴凸峰异常磨损所致。为了查找原因,对失效的挺杆体及凸轮轴进行了化学成份、物理硬度及金相结构等理化分析。结果表明,挺杆体端面的硬度不均和脆性倾向是产生此类异常磨损的主要原因。

A flight training institution abnormal metal shavings repeatedly in the oil filter of it＇s aviation piston engines during the first 100 h inspection after overhaul, this status has seriously affected flight safety. Further, disassembly check indicates that these metal shavings from abnormal wear of tappets and camshafts lobes engine insides. In order to fmd the cause of abnormal wear, the physicochemical analysis of chemic component, physics hardness and metallography structure on the failure tappets and camshaft were researched. The results show that the uneven hardness and brittleness trend of tappet face is the main cause of the abnormal wear.