항공기 보조동력장치 내 입구안내익 구동기어의 마모 결함 개선 연구

Abstract

In this study, the wear and sticking defects that occur repeatedly in the inlet guide vane (IGV) in the aircraft auxiliary power unit (APU) were analyzed. Vibration was confirmed to be the cause of the defect through two cases of improvement performed to improve the defect. Root cause corrective action (RCCA) was performed for vibration analysis, and the results of vibration analysis confirmed that the fault occurred due to friction between gears while the order component of the APU and the vibration frequency of the components matched. To improve this, a method to avoid resonance or reinforce the driving gear was proposed, and the effectiveness of four methods for applying this was verified. A proof of concept test was conducted to verify each method, which confirmed that there was no wear on the drive gear coated with lubricant. In addition, the rig test was performed to confirm that the degree of wear of the drive gear treated with salt bath decreased by approximately 1/5 compared to the conventional material. In addition, it was confirmed that the wear occurrence time of the improved shape increased more than five times compared to the previous one because the wear occurrence time of the existing shape took 182h. Through this, along with lubricant application, reinforcement of the drive gear through salt bath nitriding treatment was selected as the optimal improvement plan.