基于阶次解调谱的变速齿轮箱复合故障诊断方法

针对变速齿轮箱中复合故障的故障特征提取,提出了一种基于阶次解调谱的变速齿轮箱复合故障诊断方法。变速齿轮箱中的转速具有时变的特性,而故障特征往往与转速相关,亦具有时变特性。本文方法先用线调频小波路径追踪算法从原始振动信号中提取转频曲线,再根据转频曲线对原始振动信号进行等角度重采样,将时域非平稳信号转化为角域周期平稳信号,最后对角域周期平稳信号进行能量算子解调分析,根据阶次解调谱中的调制信息进行变速齿轮箱复合故障诊断。通过算法仿真和应用实例对包含齿轮局部故障和轴承局部故障的变速齿轮箱复合故障进行了分析,结果表明,本文方法在无转速计的情况下能有效地提取变速齿轮箱复合故障的故障特征。

A compound faults diagnosis method for changing-speed gearbox based on order tracking demodulating spectrum

Aiming at the problem of extracting fault characteristic from changing-speed gearbox with compound faults, a compound faults diagnosis method for changing-speed gearbox based on order tracking demodulating spectrum is proposed. The rotate speed of changing-speed gearbox has the characteristic of time-varying, while the fault characteristic is always related to the rotate speed, and also has the characteristic of time-varying. In the proposed method, the rotate speed is estimated from original vibration signal by chirplet path pursuit algorithm. In order to transform the time domain non-stationary signal to the angular domain cyclostationary signal, the even angle resampling is carried out to the original signal according to the obtained rotate speed. The angular domain cyclostationary signal is analyzed by energy operator demodulating, and the compound faults diagnosis of changing-speed gearbox is executed according to the modulation information in the order tracking demodulating spectrum. The results, obtained by the analysis of algorithm simulation and application examples to the changing-speed gearbox with compound faults consisted of gear local fault and bearing local fault, show that the proposed method can effectively extract fault characteristic from changing-speed gearbox with compound faults under the condition of lack of tachometer.