Wear fault diagnosis of planetary gearbox based on 
active frequency of 1.5-dimensional spectrum

BI Hao-cheng, JIANG Zhang-lei, LI Yu-heng, WU Guo-xin, WANG Hong-jun
(The Ministry of Education Key Laboratory of Modern Measurement and Control Technology, 
Beijing Information Science & Technology University, Beijing 100192, China)

Abstract: Aiming at the problem that the multiple frequency components in the planetary gearbox were coupled with each other, which led to the problem that the fault characteristics cannot be extracted,a method for the wear fault diagnosis of planetary gearbox based on the active frequency of the 1.5-dimensional spectrum (onedimensional diagonal slice spectrum of the thirdorder cumulant) was proposed. This method first was used to extend the secondary phase coupling that could be identified by the 1.5-dimensional spectrum to the secondary frequency coupling; then was used to multiply the decoupled participating coupling frequency and the coupling generation frequency point by point to obtain the active frequency; finally, by observing the relationship between the active frequency and the fault frequency, it was judged whether the planetary gearbox was malfunctioning. For the experimental part, first this method was used to extract the active frequency from the simulation signal ; then a planetary gearbox tooth surface wear failure test platform was set up to collect vibration signals, and this method was used to extract the wear failure characteristic frequency. The results indicate that the traditional Fourier transform method cannot extract the characteristic frequency of the fault, and the wear fault diagnosis method based on the active frequency of the 1.5-dimensional spectrum can extract the characteristic frequency of the fault from the vibration signal of the planetary gearbox, and realize the wear of the planetary gearbox. The diagnosis of the fault is of great significance to the diagnosis of the wear and tear of the planetary gearbox.

Key words:  planetary gearbox; fault diagnosis; 1.5-dimensional spectrum; active frequency; frequency coupling

BI Hao-cheng, JIANG Zhang-lei, LI Yu-heng, et al. Wear fault diagnosis of planetary gearbox based on active frequency of 1.5-dimensional spectrum［J］.Journal of Mechanical & Electrical Engineering, 2021,38(10):1305-1310.