Dynamic Simulation of Tooth Root Crack Failure in Planetary Gearbox Based on Torsional Vibration Signal

2020 ◽  
Author(s):  
Jingyuan Liang ◽  
Jianchuan Dai ◽  
Hang Niu ◽  
Chenggang Hou ◽  
Yunpeng Li
Keyword(s):  
Dynamic Simulation ◽  
Torsional Vibration ◽  
Vibration Signal ◽  
Tooth Root ◽  
Planetary Gearbox ◽  
Root Crack

Dynamic Simulation of Planetary Gearbox With Tooth Root Crack Based on a Rigid-Flexible Coupled Model

2019 ◽  
Author(s):  
Jianchuan Dai ◽  
Hang Niu ◽  
Chenggang Hou ◽  
Xiaodong Zhang
Keyword(s):  
Crack Propagation ◽  
Dynamic Models ◽  
Gear Tooth ◽  
Coupled Model ◽  
Vibration Signal ◽  
Propagation Path ◽  
Tooth Root ◽  
Crack Propagation Path ◽  
Planetary Gearbox ◽  
Root Crack

Abstract Tooth root crack is one of the most common failures in the gearbox which can lead to the failure of the whole transmission system. However, it is difficult to simulate the gear fault impact in practical work. To solve this problem and to study the relationship between tooth crack propagation and vibration features, various dynamic models have been built. However, the crack propagation path and the bearings are simplified in most of the models, which leads to obvious deviation in the dynamic response. In this paper, a rigid-flexible coupled model of a single-stage planetary gearbox in normal and fault conditions are built by ADAMS software. The crack propagation path is considered a parabolic curve and the thickness of the crack decreases along the path. As a reference, a rigid-body model has also been built to prove that the rigid-flexible coupled model can be more accurate and suitable for analyzing the response of the planetary gearbox with fault. Afterward, the effects of gear tooth root crack size on the gear dynamics are simulated and the corresponding changes in statistical indicators are investigated. By studying the torsional vibration signal of the planetary gearbox with varying severity of the damage, the fault characteristics and damage evolution mechanics can be analyzed and by comparing the fault sensitivity of these indicators, the critical and sensitive fault indicators are screened out.

Wind Turbine Planetary Gearbox Fault Analysis Based on Bispectrum

2014 ◽  
Vol 1070-1072 ◽  
pp. 1861-1868
Author(s):  
Yong Xin Feng ◽  
Wei Peng Zhang ◽  
Tao Yang ◽  
Xiao Wen Deng ◽  
Shi Liu
Keyword(s):  
Wind Turbine ◽  
Vibration Signal ◽  
Noise Signal ◽  
Fault Analysis ◽  
Planetary Gearbox ◽  
Quadratic Phase ◽  
Signal Characteristics ◽  
Coupling Phenomena ◽  
Quadratic Coupling ◽  
Root Crack

Through researching the fault vibration signal characteristics of planetary gearbox, various forms of quadratic phase coupling phenomenon were found in the signals. Bispectrum has properties such as detecting the quadratic coupling phenomena and restraining gaussian noise signal, and it can be well used in the planetary gearbox fault diagnosis. Meanwhile, the sun gear distributed fault (gear wear) and partial fault (root crack, partial broken teeth) are simulated in the wind turbine test bench built in the laboratory. By analyzing the structure characteristics of its frequency through bispectrum, the fault of the gear is effectively diagnosed.

scholarly journals Root Crack Identification of Sun Gear in Planetary Gear System Combining Fault Dynamics with VMD Algorithm

2021 ◽  
Vol 2021 ◽  
pp. 1-24
Author(s):  
Hongwei Fan ◽  
Yiqing Yang ◽  
Hongwei Ma ◽  
Xuhui Zhang ◽  
Xiang Wan ◽  
...  
Keyword(s):  
Planetary Gear ◽  
Gear System ◽  
Crack Identification ◽  
Crack Model ◽  
Tooth Root ◽  
Intrinsic Mode Functions ◽  
Dynamics Model ◽  
Planetary Gearbox ◽  
Planetary Gear System ◽  
Root Crack

Planetary gearbox is widely used in various low-speed machines due to its large transmission ratio. However, the gears in a planetary gearbox are prone to the mechanical faults due to the complex dynamic heavy load. Vibration frequencies caused by an early tooth root crack of sun gear are usually difficult to accurately extract, so its fault diagnosis is one of the main challenges of planetary gearbox reliability. In this paper, a simplified tooth root crack model of sun gear is proposed, and then a rigid-flexible coupled dynamics model of the whole planetary gear system is constructed. By the numerical simulation, the fault frequencies caused by a tooth root crack of sun gear are obtained. A Variational Mode Decomposition (VMD) algorithm for the vibration frequency extraction is proposed. The measured vibration signals are decomposed into the sparse Intrinsic Mode Functions (IMFs) by the VMD, and then the IMFs are further analyzed by the spectral method to accurately extract the crack-induced frequency components. The experimental results show that the proposed dynamics model and VMD method are feasible; an error between the characteristic frequencies from the tested signal analysis and the theoretical calculation is less than 1%.

scholarly journals Preliminary Evaluation of the Influence of Surface and Tooth Root Damage on the Stress and Strain State of a Planetary Gearbox: An Innovative Hybrid Numerical–Analytical Approach for Further Development of Structural Health Monitoring Models

Computation ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 38
Author(s):  
Franco Concli ◽  
Athanasios Kolios
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Analytical Approach ◽  
Surface Defects ◽  
Local Stress ◽  
Computational Effort ◽  
Preliminary Evaluation ◽  
Tooth Root ◽  
Planetary Gearbox ◽  
Structural Health

Wind turbine gearboxes are known to be among the weakest components in the system and the possibility to study and understand the behavior of geared transmissions when subject to several types of faults might be useful to plan maintenance and eventually reduce the costs by preventing further damage. The aim of this work is to develop a high-fidelity numerical model of a single-stage planetary gearbox selected as representative and to evaluate its behavior in the presence of surface fatigue and tooth-root bending damage, i.e., pits and cracks. The planetary gearbox is almost entirely modelled, including shafts, gears as well as bearings with all the rolling elements. Stresses and strains in the most critical areas are analyzed to better evaluate if the presence of such damage can be somehow detected using strain gauges and where to place them to maximize the sensitivity of the measures to the damage. Several simulations with different levels, types and positions of the damage were performed to better understand the mutual relations between the damaged and the stress state. The ability to introduce the effect of the damage in the model of a gearbox represents the first indispensable step of a Structural Health Monitoring (SHM) strategy. The numerical activity was performed taking advantage of an innovative hybrid numerical–analytical approach that ensures a significant reduction of the computational effort. The developed model shows good sensitivity to the presence, type and position of the defects. For the studied configuration, the numerical results show clearly show a relation between the averaged rim stress and the presence of root cracks. Moreover, the presence of surface defects seems to produce local stress peaks (when the defects pass through the contact) in the instantaneous rim stress.

3-D elastic coupling vibration and acoustical radiation characteristics of cracked gear under elastic support condition

2015 ◽  
Vol 23 (9) ◽  
pp. 1548-1568 ◽  
Author(s):  
Shao Renping ◽  
Purong Jia ◽  
Xiankun Qi
Keyword(s):  
Dynamic Response ◽  
Support System ◽  
Three Dimensional ◽  
Elastic Support ◽  
Dynamic Responses ◽  
Tooth Root ◽  
Support Condition ◽  
Elastic Boundary ◽  
Root Crack ◽  
Elastic Disc

According to the actual working condition of the gear, the supporting gear shaft is treated as an elastic support. Its impact on the gear body vibration is considered and investigated and the dynamic response of elastic teeth and gear body is analyzed. On this basis, the gear body is considered as a three-dimensional elastic disc and the gear teeth are treated as an elastic cantilever beam. Under the conditions of the elastic boundary (support shaft), combining to the elastic disk and elastic teeth, the influence of three-dimensional elastic discs on the meshing tooth response under an elastic boundary condition is also included. A dynamic model of the gear support system and calculated model of the gear tooth response are then established. The inherent characteristics of the gear support system and dynamics response of the meshing tooth are presented and simulated. It was shown by the results that it is correct to use the elastic support condition to analyze the gear support system. Based on the above three-dimensional elastic dynamics analysis, this paper set up a dynamics coupling model of a cracked gear structure support system that considered the influence of a three-dimensional elastic disc on a cracked meshing tooth under elastic conditions. It discusses the dynamic characteristic of the cracked gear structure system and coupling dynamic response of the meshing tooth, offering a three-dimensional elastic body model of the tooth root crack and pitch circle crack with different sizes, conducting the three-dimensional elastic dynamic analysis to the faulty crack. ANSYS was employed to carry out dynamic responses, as well as to simulate the acoustic field radiation orientation of a three-dimensional elastic crack body at the tooth root crack and pitch circle with different sizes.

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