Analysis of coupling fault correlation and nonlinear vibration of multi-stage gear transmission system

Abstract

In the multistage gear transmission system, when multiple faults are coupled, the faults with weak signals are often hidden and hard to identify. Multi-fault coupling may also cause new coupling fault characteristics, such as new peaks or side bands in the spectrum. These characteristics are likely to contain fault information. Studying the sources of frequency components in coupled fault signals will help to decouple the signals and dig out the correlation characteristics between faults. The coupling fault of fixed-axis gear crack and planetary gear tooth broken was studied in this paper. The nonlinear dynamic model of the multi-stage gear transmission system was used for simulation, and the fault frequency characteristics of the system varying with the excitation frequency were obtained. The short-time Fourier transform (STFT) and waterfall plot analysis were applied to the experimental signals to separate the fault features. By comparing the theoretical and experimental signals, we found the natural frequency of the system, the side frequency characteristics of single fault and coupling fault, and the cause of new peaks. This study has a guiding significance for the separation and identification of coupling faults of the multi-stage gear transmission system.

Nonlinear Dynamics of a Multi-shaft Gear System in Parameter-state Space

“…Besides, the experimental method is also the key way to verify and correct the theoretical analysis of dynamic characteristics in the gear system. Zhao, Rigaud, Martynenko and their co-workers [13][14][15] built vibration testing benches for different types of gear transmission systems and verified the accuracy and feasibility of system dynamics behavior by the diagrams of phase, bifurcation and time domain. With the development of nonlinear dynamics theories, Saghafi, Donmez, Arian, et al [16][17][18] used the numerical simulation results of the gear system dynamic responses to study how to suppress or eliminate chaotic behavior.…”

Study on the Vibration Characteristics of the Helical Gear-Rotor-Bearing Coupling System of a Wind Turbine with Composite Faults

“…For the study of gear dynamics with composite faults, Liang and Zuo [20] published a review on gear fault dynamic modeling, in which they pointed out that establishing more efficient and accurate dynamic models containing composite faults is an important task for future gear dynamics research. Zhao et al [21] took into account that it is difficult to identify the faults with weak signals in a multistage gear transmission system that contains multiple faults in the case of coupled faults and established a fixed-axis nonlinear dynamics model of the coupled faults of gear crack and planetary gear broken teeth, obtained the fault frequency characteristics of the system with the change of excitation frequency, and by comparing the theoretical and experimental signals, obtained the intrinsic frequency of the system, the side frequency characteristics of the single faults, and the coupled faults. Cao et al [22] proposed a time-varying mesh stiffness calculation method for the fatigue cracks and wear-coupled faults, then combined them with the coupled fault evolution model and established the coupled fault evolution model.…”