某型涡扇发动机中介轴承微弱故障特征信号提取技术

研究航空发动机在降转速过程中中介轴承微弱故障特征信号的提取技术,提出了一种基于计算阶次分析、三次样条插值分析与包络谱分析相结合的新方法。基于滚动轴承模拟故障实验和航空发动机中介轴承微弱故障实验测得的降速工况下的转速信号和振动信号,首先对转速信号在时域内积分获得角位移-时间信号;再对该信号进行线性插值获得等角度间隔的角位移-时间信号;然后利用该时间序列对振动信号进行三次样条差值获得等角度间隔分布的重采样振动信号;最后对重采样振动信号进行包络分析及快速傅里叶变换获得阶次包络谱。通过两种实验分析表明该方法能有效提取出复杂路径下航空发动机中介轴承微弱故障特征信息。该方法为航空发动机中介轴承微弱故障特征信号提取提供了一种重要手段,具有广泛的应用前景。

Technology to extract weak fault characteristic signal of intermediate bearing of some turbofan engine

In this paper, the extractive technique of weak fault characteristic signal of the intermediate bearing of aero-engine under the lowing speed condition is presented, and a new method based on calculation order analysis, cubic spline interpolation analysis and envelope spectrum analysis is presented. They were based on the speed signal and vibration signal of the run-down condition measured by the weak fault experiment of rolling bearing and the aircraft engine intermediate bearing weak failure experiment. Firstly, the angular displacement - time signal was obtained by integrating the speed signal in the time domain, then the angular displacement - time signal was obtained by the linear interpolation of the signal. Then, the re-sampling vibration signal of the interval distribution was obtained by the three samples of the vibration signal which is used the angular displacement - time signal. Finally, the order envelope spectrum was got by the re-sampling vibration signal envelope analysis and fast Fourier transform. The analysis results of two experiments show that this method can extract the weak fault feature information of the intermediate bearing of aero-engine under complex path. This may provide a virtual basis on the signal extraction of the aircraft engine intermediate bearing weak fault feature and has widely application prospect.