scholarly journals Dynamic Analysis of Planetary Gear with Root Crack in Sun Gear Based on Improved Time-Varying Mesh Stiffness

2020 ◽  
Vol 10 (23) ◽  
pp. 8379
Author(s):  
Jian Shen ◽  
Niaoqing Hu ◽  
Lun Zhang ◽  
Peng Luo
Keyword(s):  
Fault Diagnosis ◽  
Dynamic Model ◽  
Theoretical Basis ◽  
Planetary Gear ◽  
Vibration Response ◽  
Gear System ◽  
Transition Curve ◽  
Parameter Method ◽  
Time Varying ◽  
Mesh Stiffness

The time-varying mesh stiffness (TVMS) is the crucial parameter of the dynamic model of the gear system. Accurate calculation of TVMS is essential for effective fault diagnosis of the gear system. A mesh stiffness improved method considering both the gear tooth transition curve and deformation of the gear body is presented in this paper, and the stiffness calculation expressions under healthy and crack states are given, respectively. Based on the lumped parameter method, the dynamic model of planetary gear with crack in sun gear is constructed, and the vibration response is solved. The simulation results show when the tooth root cracks appear, the vibration response of the tooth has obvious shock response characteristics. The characteristic frequency and frequency multiplication of sun gear fault can be found obviously by envelope analysis. The simulation signal and the test signal obtained by the drivetrain dynamics simulator gearbox test rig are compared and verified. The comparison and verification results show that the proposed TVMS calculation method and the dynamic model are accurate, which can provide a certain theoretical basis for the fault diagnosis of planetary gear with crack fault. The test results are consistent with the numerical analysis results, which provides a theoretical basis for the fault diagnosis of tooth crack.

scholarly journals Dynamic modeling and vibration analysis of a cracked 3K-II planetary gear set for fault detection

2021 ◽  
Vol 12 (2) ◽  
pp. 847-861
Author(s):  
Meng Sang ◽  
Kang Huang ◽  
Yangshou Xiong ◽  
Guangzhi Han ◽  
Zhenbang Cheng
Keyword(s):  
Fault Diagnosis ◽  
Torsional Vibration ◽  
Gear Tooth ◽  
Planetary Gear ◽  
Gear System ◽  
Gear Train ◽  
Lumped Parameter Model ◽  
Time Varying ◽  
Vibration Signals ◽  
Planetary Gear System

Abstract. The 3K planetary gear system is a basic planetary transmission structure with many advantages over the 2K-H planetary gear system. However, the vibration characteristics will be more complicated due to the increase of central gears meshing with each planet gear simultaneously. In this paper, a lumped-parameter model for a 3K-II planetary gear set was developed to simulate the dynamic response. The time-varying stiffness of each meshing pair for different gear tooth root crack faults is calculated via the finite element method. By considering the effect of time-varying transmission paths, the transverse synthetic vibrations are obtained. Subsequently, the feasibilities of transverse synthetic vibration signals and output torsional vibration signals as reference for fault diagnosis are analyzed by studying the time-domain and frequency-domain characteristics of these two vibration signals. The results indicate that both the transverse synthetic vibration signals and output torsional vibration signals can be used for fault identification and localization of the 3K-II planetary gear train, and yet they both have their limitations. Some results of this paper are available as references for the fault diagnosis of 3K planetary gear trains.

Influence of Sliding Friction on the Dynamic Characteristics of a Planetary Gear Set With the Improved Time-Varying Mesh Stiffness

2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Wei Luo ◽  
Baijie Qiao ◽  
Zhixian Shen ◽  
Zhibo Yang ◽  
Hongrui Cao ◽  
...  
Keyword(s):  
Dynamic Model ◽  
Dynamic Characteristics ◽  
Sliding Friction ◽  
Planetary Gear ◽  
Time Varying ◽  
Mesh Stiffness ◽  
Friction Forces ◽  
Basic Model ◽  
Internal Excitation ◽  
Improved Model

Abstract Acting as an important internal excitation, sliding friction can cause the vibration and noise of the planetary gear set. In this paper, a dynamic model is developed to study the influence of sliding friction on the dynamic characteristics of the planetary gear set by including the time-varying mesh stiffness (TVMS), sliding friction forces and torques. An improved analytical model is proposed to calculate the TVMS with sliding friction. The explicit analytical expressions of the sliding friction forces and torques are also derived. Three kinds of different models are applied to investigate the influence of sliding friction: (1) the basic model: sliding friction is neglected in the dynamic model; (2) the improved model I: only the sliding friction forces and torques are considered in the dynamic model; and (3) the improved model II: both the influence of sliding friction on the TVMS and the sliding friction forces and torques are introduced into the dynamic model. The planetary gear set with three equally spaced planet gears is applied to analyze the dynamic characteristics under sliding friction. The simulation results show that the dynamic characteristics can be enhanced or disturbed by sliding friction. In the end, the dynamic model is validated by the experiments. Therefore, the influence of sliding friction is non-negligible when investigating the dynamic characteristics of the planetary gear set. The developed dynamic model provides a feasible dynamic research scheme for the planetary gear set with sliding friction.

Torsional Vibrations and Dynamic Loads in a Basic Planetary Gear System

1986 ◽  
Vol 108 (3) ◽  
pp. 348-353 ◽  
Author(s):  
R. August ◽  
R. Kasuba
Keyword(s):  
Dynamic Model ◽  
Degrees Of Freedom ◽  
Planetary Gear ◽  
Gear System ◽  
Dynamic Loads ◽  
Ring Gear ◽  
Gear Mesh ◽  
Input And Output ◽  
Planetary Gear System ◽  
Three Degrees Of Freedom

An interative method has been developed for analyzing dynamic loads in a light weight basic planetary gear system. The effects of fixed, semi-floating, and fully-floating sun gear conditions have been emphasized. The load dependent variable gear mesh stiffnesses were incorporated into a practical torsional dynamic model of a planetary gear system. The dynamic model consists of input and output units, shafts, and a planetary train. In this model, the sun gear has three degrees of freedom; two transverse and one rotational. The planets, ring gear, and the input and output units have one degree of freedom, (rotation) thus giving a total of nine degrees of freedoms for the basic system. The ring gear has a continuous radial support. The results indicate that the fixed sun gear arrangement with accurate or errorless gearing offers in general better performance than the floating sun gear system.

Calculation of time dependent mesh stiffness of helical planetary gear system using analytical approach

2018 ◽  
Vol 32 (8) ◽  
pp. 3537-3545 ◽  
Author(s):  
Mohsen Rezaei ◽  
Mehrdad Poursina ◽  
Shahram Hadian Jazi ◽  
Farhad Haji Aboutalebi
Keyword(s):  
Analytical Approach ◽  
Planetary Gear ◽  
Gear System ◽  
Time Dependent ◽  
Mesh Stiffness ◽  
Planetary Gear System

Dynamic Response Analysis of Wind Turbine Planetary Gear System With Interval Stiffness Parameters

2014 ◽  
Author(s):  
Sha Wei ◽  
Qinkai Han ◽  
Zhipeng Feng ◽  
Yanhua Shen ◽  
Fulei Chu
Keyword(s):  
Wind Turbine ◽  
Planetary Gear ◽  
Transmission Error ◽  
Gear System ◽  
Dynamic Responses ◽  
Lumped Parameter Model ◽  
Response Analysis ◽  
Mesh Stiffness ◽  
Gear Trains ◽  
Planetary Gear System

Planetary gear transmission system is one of the primary parts of the wind turbine drive train. Due to the assembly state, lubrication conditions and wear, the mesh stiffness of the planetary gear system is an uncertain parameter. In this paper, taking the uncertainty of mesh stiffness into account, the dynamic responses of a wind turbine gear system subjected to wind loads and transmission error excitations are studied. Firstly, a lumped-parameter model is extended to include both the planetary and parallel gears. Then the fluctuation ranges of dynamic mesh forces are predicted quantitatively and intuitively based on the combined Chebyshev interval inclusion function and numerical integration method. Finally, examples of gear trains with different interval mesh stiffnesses are simulated and the results show that tooth separations are becoming more obvious at the resonant speed by considering the fluctuating mesh stiffness of the second parallel gear stage. The nonlinear tooth separations are degenerated obviously as the fluctuation error of the mesh stiffness of the second parallel gear set is increased.

scholarly journals Dynamic Model of Spur Gear Pair with Modulation Internal Excitation

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Zhong Wang ◽  
Lei Zhang ◽  
Yuan-Qing Luo ◽  
Chang-Zheng Chen
Keyword(s):  
Dynamic Model ◽  
Transmission Error ◽  
Spur Gear ◽  
Experimental Result ◽  
Time Varying ◽  
Gear Pair ◽  
Mesh Stiffness ◽  
Gear Mesh ◽  
Internal Excitation ◽  
Modulation Sideband

In the actual measurements, vibration and noise spectrum of gear pair often exhibits sidebands around the gear mesh harmonic orders. In this study, a nonlinear time-varying dynamic model of spur gear pair was established to predict the modulation sidebands caused by the AM-FM modulation internal excitation. Here, backlash, modulation time-varying mesh stiffness, and modulation transmission error are considered. Then the undamped natural mode was studied. Numerical simulation was made to reveal the dynamic characteristic of a spur gear under modulation condition. The internal excitation was shown to exhibit obvious modulation sideband because of the modulation time-varying mesh stiffness and modulation transmission error. The Runge-Kutta method was used to solve the equations for analyzing the dynamic characteristics with the effect of modulation internal excitation. The result revealed that the response under modulation excitation exhibited obvious modulation sideband. The response under nonmodulation condition was also calculated for comparison. In addition, an experiment was done to verify the prediction of the modulation sidebands. The calculated result was consistent with the experimental result.

Effects of Temperature on the Time-Varying Mesh Stiffness, Vibration Response, and Support Force of a Multi-Stage Planetary Gear

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Hui Liu ◽  
Pengfei Yan ◽  
Pu Gao
Keyword(s):  
Temperature Change ◽  
Dynamic Characteristics ◽  
Nonlinear Dynamic ◽  
Thermal Deformation ◽  
Planetary Gear ◽  
Time Varying ◽  
Mesh Stiffness ◽  
Vibration Displacement ◽  
Influence Of Temperature ◽  
Nonlinear Dynamic Characteristics

Abstract The thermal deformation of gears will affect the vibration of the planetary system; this research mainly studied the effect of thermal conditions on planetary systems nonlinear vibration under the thermal equilibrium state. To study the influence of gear temperature on the planetary gear system, a nonlinear dynamic model considering thermal deformation was established. The mathematical expression of the thermal time-varying mesh stiffness (TTVMS) varied with temperature, and the backlash caused by the temperature change was also computed. The influence of temperature on the TTVMS was investigated. The calculation results indicated that the methods used to determine the TTVMS and backlash of gear pairs were effective, and the trends of the change in the nonlinear dynamic characteristics with temperature were obtained. According to the fast Fourier transform (FFT) spectrums and root-mean-square (RMS) analysis, the influence of temperature change on the nonlinear dynamic characteristics of the system was analyzed. When the temperature was lower than 80 °C, the vibration displacement and the supporting shaft load remained unchanged or decreased. Once the temperature was higher than 80 °C, the vibration displacement and load of the system were strengthened.

Effects of gear eccentricity on time-varying mesh stiffness and dynamic behavior of a two-stage gear system

2019 ◽  
Vol 33 (3) ◽  
pp. 1019-1032 ◽  
Author(s):  
Xiuzhi He ◽  
Xiaoqin Zhou ◽  
Zhen Xue ◽  
Yixuan Hou ◽  
Qiang Liu ◽  
...  
Keyword(s):  
Dynamic Behavior ◽  
Gear System ◽  
Time Varying ◽  
Mesh Stiffness ◽  
Two Stage
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