基于变分模式分解的行星齿轮箱齿轮组合故障频率解调分析

行星齿轮箱组合故障振动信号具有多源调制特点,在频域内边带结构复杂,通过常规Fourier频谱分析难以有效提取故障特征;组合故障振动信号的调频部分包含故障信息,且不受传递路径影响。为了准确提取行星齿轮箱组合故障特征,提出基于变分模式分解的频率解调分析方法。根据采样频率和载波频率确定单分量个数,通过变分模式分解将多分量信号自适应地分解为一系列本质模式函数;计算本质模式函数的瞬时频率,根据中心频率和啮合频率的匹配关系选取敏感单分量;通过分析敏感单分量瞬时频率频谱诊断组合故障。通过仿真信号和实验信号分析验证了方法的有效性,诊断了太阳轮与行星轮、太阳轮与齿圈、行星轮与齿圈的组合故障。

Combined fault frequency demodulation analysis for a planetary gearbox based on VMD

Combined fault vibration signals of a planetary gearbox with features of multi-source modulation and complex sideband structure in frequency domain.It is difficult to effectively extract gear fault features with conventional Fourier spectral analysis.However, the frequency modulation part of combined fault vibration signals contains fault information and is independent on the vibration transfer path.Here, a frequency demodulation analysis method based on the variational mode decomposition was proposed to extract combined fault features of a planetary gearbox.Firstly, the single-component number was determined according to sampling frequency and carrier one.Then, a multi-component signal was adaptively decomposed into a series of intrinsic mode functions with the variational mode decomposition.Instantaneous frequency of each intrinsic mode function was calculated, and sensitive single-component was selected according to the matching relation between central frequency and meshing one.Finally, instantaneous frequency spectrum of each sensitive single-component was analyzed to diagnose combined faults.The effectiveness of the proposed method was verified through analyzing simulated vibration signals and test ones, and combined faults of sun gear-planet one, sun gear-gear ring and planet gear-gear ring were diagnosed.