中文摘要：

调频部分包含齿轮故障信息，而且不受振动传递路径变化的影响。为了避免振动信号频谱的复杂边带结构以及行星轮通过效应或时变振动传递路径的影响，根据行星齿轮箱振动信号的调频特点，提出了基于经验模式分解的频率解调分析方法。提出了本质模式函数的选择原则，推导了瞬时频率Fourier频谱的解析表达式，总结归纳了太阳轮、行星轮和齿圈故障振动信号瞬时频率Fourier频谱的频率结构特点。应用仿真信号和故障实验数据验证了上述理论分析结果，通过频率解调分析诊断出了太阳轮、行星轮和齿圈的局部损伤故障。

英文摘要：

The frequency modulation part contains the gear fault information, and is free from the effect of time varying vibration transfer paths. This feature is helpful to avoid the complex sidebands in Fourier spectra and additional amplitude modulation caused by the planet passing effect or the time variant vibration propagation paths. According to the frequency modulation characteristics of planetary gearbox vibration signals, a frequency demodulation analysis method based on empirical mode decomposition was proposed to simplify the signal analysis in fault diagnosis. The criterion for selecting sensitive intrinsic mode function was proposed, the explicit equations for the Fourier spectra of instantaneous frequency were deduced, and the instantaneous frequency spectral characteristics of sun, planet and ring gear faults were summarized. The proposed method was validated using simulated signal and lab experimental datasets, and the localized damage of sun, planet and ring gears was diagnosed via frequency demodulation analysis.