A Study on Coupling Faults’ Characteristics of Fixed-Axis Gear Crack and Planetary Gear Wear

Xin Wang

doi:10.1155/2018/4692796

Abstract

To identify the fault frequency characteristics of the gear transmission system under coupling fault of fixed-axis gear crack and planetary gear wear, dimensionless dynamical equations of gear transmission system were established. Bifurcations in normal condition and coupling fault condition were contrasted. The affected excitation frequency range was found. Fault frequency characteristics in sensitive interval caused by the coupling fault of fixed-axis gear crack and planetary gear wear were analyzed. Simulation analysis shows that the crack fault in fixed-axis gear brings up peaks in doubling of 1~10 for fault frequency, the wear fault in planetary gear increases the amplitude of meshing frequency and its double and triple, and the coupling of both shows two kinds of fault features around the planetary gear meshing frequency.

Highlights

The wind turbine gearbox is the core component of the wind turbine; its transmission system is a multistage gear transmission system with a two-stage fixed-axis gear and a one-stage planetary gear
When the system has the coupling fault, the fault characteristics are similar to single fixed-axis crack fault when the excitation frequency is less than 3, and the fault characteristics are similar to single planetary gear wear fault when the excitation frequency is greater than 3
With contrasted bifurcation and frequency spectrum characteristics of system in normal condition and coupling faults condition, it found that when the system has the coupling fault, the fault characteristics are similar to single fixed-axis crack fault when the excitation frequency is less than 3, and the fault characteristics are similar to single planetary gear wear fault when the excitation frequency is greater than 3

Summary

Introduction

The wind turbine gearbox is the core component of the wind turbine; its transmission system is a multistage gear transmission system with a two-stage fixed-axis gear and a one-stage planetary gear. By studying the vibration mechanism and fault mechanism of the multistage gear transmission system and finding out the complex signal correlation characteristics caused by the fault, can the early fault of the gear be identified by the signal processing method. For the study of coupling faults, Li et al [1, 2] used the combined intelligent signal analysis method based on wavelet packet, empirical mode decomposition, Wigner distribution, and AR model to identify five single faults and three coupling faults. In the article [6], the coupling fault of fixed-axis crack and planetary gear chipping was studied from the nonlinear angle, and the fault frequency characteristics of the coupling fault were analyzed. According to the numerical simulation results, the fault frequency of the measured signal is identified

Torsional Dynamic Model of Gear

Analysis of Nonlinear Dynamic Behavior of Coupling Fault

Experimental Failure Analysis

Conclusion