某型发动机中下水平齿轮断裂故障分析及改进

Fracture Analysis and Process Improvement of Horizontal Gears in Center and Below

对发生于外场的因发动机空中停车导致的一起二等事故进行了故障分析,针对Z8齿轮双向弯曲疲劳断裂的这个直接失效特征,通过与原型样机进行差异对比分析,找出了中传动匣与最新状态原型机样件的差异,并制订了整机振动测试方案和不同状态的中传动匣与全套不同齿型齿轮的振动应力测试部件试验方案。通过进行整机试验与部件试验对比,并结合振动特性分析,证明了中传动匣自身刚度不足为本次事故的主要原因,而零度弧齿锥齿轮与直齿锥齿轮的差异为本次事故的次要原因。在此基础上,以最新状态的原型机中传动匣样件做为改进设计的依据,重新对中传动匣进行了测绘,并在改进措施贯彻到位之前,对部队正常使用发动机需采取的监控措施进行了研究,制订了完善的使用监控措施并组织实施,确保了部队的正常训练及使用安全。

A second class accident caused by engine in-flight shutdown which happened in the field is analyzed. Accord- ing to the direct failure characteristic of gears compound bending fatigue fracture of Z8 engine, after contrast analysis with the prototype engine, we find out the differences between the central gear box and the latest prototype engine. Then we draw up the overall engine vibration testing plan and the vibration stress test plan for centric gear box and full set of different gear dental shape under different condition according to the differences between the central gear box and the latest prototype engine. We drew a conclusion that the first cause of the accident is centric gear being short of rigidity and the secondary cause is odds between zero degree spiral bevel gear and the straight bevel gear. Based on all above, we resurvey the centric gear box, regarding the latest gear box of the prototype engine as the reference. Before carrying out all the improvement, the army＇s monitoring measures for the engine in normal use is studied and a better monitoring measure is established and organized to carry out. Therefore, it ensures the army＇s daily training and safety in running.