某航空发动机滑油位异常下降故障分析

针对某航空发动机在试飞过程中连续出现多起滑油箱油位异常下降情况,对滑油系统进行排查分析,确认为由滑油泵皮碗裂纹引起的。经对皮碗故障件进行复查、断口分析、设计复查等工作,确定了皮碗裂纹产生的原因。结果表明:滑油泵级间壳体上通油孔与增压泵出口相连,使得皮碗封严压力过大,为导致皮碗裂纹故障发生的主要原因;泵轴与皮碗装配过盈量大促进了皮碗裂纹故障萌生和扩展。通过对滑油泵结构参数优化设计,降低皮碗承载油压和摩擦力,提高皮碗密封性能和寿命,从而有效避免此类故障再次发生。

Failure Analysis of Oil Level Abnormally Declined for an Aeroengine

Aiming at the problem of oil level of tank anomaly declined occurred several times in the flighttest for aeroengine, the reason was identified that the crack of oil pump seal cup caused oil level decline through the analysis of lubrication system. According to the faulty component review, fracture analysis and design review, the cause of failure was identified finally. The result shows that the oilthrough hole in the oil pump''s inter stage shell is connected with pressure pump''s outlet. It resulted that seal cup''s sealing pressure was too large, which was the main reason of the occurrence of seal cup crack fault. The large interference between seal cup and pump''s axial is the auxiliary reason. The hydraulic pressure and friction of the cup seal is reduced through the optimization design of structure parameters of oil pump, and the sealing performance and life is improved, accordingly, the analogous failure can be avoided