Analysis of nonlinear dynamic characteristic of a planetary gear system considering tooth surface friction

2021 ◽  
pp. 135065012199174
Author(s):  
Jingyue Wang ◽  
Ning Liu ◽  
Haotian Wang ◽  
Jiaqiang E
Keyword(s):  
Damping Ratio ◽  
Excitation Frequency ◽  
Planetary Gear ◽  
Gear System ◽  
Tooth Surface ◽  
Lumped Mass ◽  
Heavy Load ◽  
Light Load ◽  
Planetary Gear System ◽  
Bifurcation Behavior

Based on the lumped mass method, a torsional vibration model of the planetary gear system is established considering the nonlinear factors such as friction, time-varying meshing stiffness, backlash, and comprehensive error. The Runge–Kutta numerical method is used to analyze the motion characteristics of the system with various parameters and the influence of tooth friction on the bifurcation and chaos characteristics of the system. The numerical simulation results show that the system has rich bifurcation behavior with the excitation frequency, damping ratio, comprehensive error amplitude, load and backlash, and experiences multiple periodic motion and chaotic motion. Tooth friction makes the bifurcation behavior of the system fuzzy in the high frequency and heavy load areas, makes the chaos of the system restrained in the low-damping ratio and light load areas, advances the bifurcation point of the system in the small comprehensive error amplitude area, and makes the period window of the chaos area larger in the large-backlash area, which makes the bifurcation behavior of the system more complex.

Research on bifurcation and chaos characteristics of planet gear transmission system with mixed elastohydrodynamic lubrication (EHL) friction

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jingyue Wang ◽  
Ning Liu ◽  
Haotian Wang ◽  
Lixin Guo
Keyword(s):  
Periodic Motion ◽  
Elastohydrodynamic Lubrication ◽  
Planetary Gear ◽  
Surface Friction ◽  
Gear System ◽  
Tooth Surface ◽  
Gear Transmission System ◽  
Planet Gear ◽  
Planetary Gear System ◽  
Ehl Friction

Abstract In order to study the influence of friction on the nonlinear dynamic characteristics of a planetary gear system, the dynamic model of a planet gear transmission system considering mixed elastohydrodynamic lubrication (EHL) friction, time-varying meshing stiffness, backlash and comprehensive meshing error is established. The Runge–Kutta method is used to solve the dynamic differential equations, and the bifurcation and chaos characteristics of the system are analysed through the bifurcation diagram, largest lyapunov exponent (LLE), Poincaré map, phase diagram, time history curve diagram and fast fourier transform (FFT)spectrum. The results of numerical simulation show that the planetary gear system with mixed EHL friction exhibits rich bifurcation characteristics, and the system experiences short-periodic motion, long-periodic motion, quasi-periodic motion and chaotic motion. The effect of tooth surface friction on the bifurcation characteristics of the planetary gear system is more obvious at high frequency than that at low frequency. Tooth surface friction causes the system to enter chaotic motion in advance.

scholarly journals Dynamic Analysis of a Fault Planetary Gear System under Nonlinear Parameter Excitation

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Jianchao Han ◽  
Yinghui Liu ◽  
Lei Liang ◽  
Yang Zhao ◽  
Huibo Zhang
Keyword(s):  
Equations Of Motion ◽  
Excitation Frequency ◽  
Global Bifurcation ◽  
Planetary Gear ◽  
Gear System ◽  
Fault System ◽  
Nonlinear Dynamic Model ◽  
Motion State ◽  
Planetary Gear System ◽  
Potential Energy Method

In order to facilitate lubrication and avoid the gear stuck due to thermal expansion, there needs to be a gap between the tooth profiles. As a strong nonlinear factor, the backlash will affect the motion state of the planetary gear system. When the gear failures occur, the motion state of the system will accordingly change. In this study, the meshing stiffness of the gear pair with tooth tip chipping fault is calculated by combining the analytic geometry method and the potential energy method. Then, a new nonlinear dynamic model including tooth backlash, time-varying mesh stiffness, and manufacturing error is established to study the dynamic response of the system. The equations of motion are derived by the Lagrangian method and solved by the numerical integration method. Taking the excitation frequency and tooth backlash as the variation parameters, respectively, the dynamic characteristics of the system are analyzed by comparing the global bifurcation diagrams between the health system and the fault system, and the path of the system into chaos is revealed. At the same time, the local characteristics of the system are revealed through the phase diagrams and Poincaré maps. The results show that with the variation of excitation frequency and tooth backlash, the fault system presents a more complex motion state. This study can provide the theoretical support for dynamic design and fault diagnosis of planetary gear transmission systems under the environment of gear fault-prone.

Dynamical load sharing behaviors of heavy load planetary gear system with multi-floating components

2018 ◽  
Vol 09 (01) ◽  
pp. 1850005 ◽  
Author(s):  
Xiangyang Xu ◽  
Tianhong Luo ◽  
Jiayuan Luo ◽  
Xia Hua ◽  
Reza Langari
Keyword(s):  
Planetary Gear ◽  
Load Sharing ◽  
External Input ◽  
Gear System ◽  
Central Component ◽  
Heavy Load ◽  
Position Errors ◽  
Planet Gear ◽  
Planetary Gear System ◽  
Input Load

To investigate the dynamical load sharing behaviors of multi-floating components in the heavy load planetary gear system, a multi-floating planetary gear system that includes a floating central component and a quasi-floating planet flexible supporting pin is employed. Then a 21 degree of freedom lumped parameters dynamical model of this system is presented to study the dynamical load sharing behaviors. Some influencing factors, such as supporting stiffness, positions error of sun or carrier, and external input load are analyzed on the dynamical load sharing of the planetary gear system with multi-floating components. The results demonstrate that the load sharing condition of the system is best when both the sun gear and planet gears are multi-floating at the same time. When the planet gear position errors remain constant, reducing the flexible pin stiffness of planet gear or increasing external input load can effectively improve the load sharing. These conclusions are verified by the relevant experiments.

An analyzing method of coupled modes in multi-stage planetary gear system

2014 ◽  
Vol 15 (11) ◽  
pp. 2357-2366 ◽  
Author(s):  
Wei Sun ◽  
Xin Ding ◽  
Jing Wei ◽  
Xinglong Hu ◽  
Qingguo Wang
Keyword(s):  
Planetary Gear ◽  
Gear System ◽  
Coupled Modes ◽  
Multi Stage ◽  
Planetary Gear System

Effect of the bearing clearance on vibrations of a double-row planetary gear system

2019 ◽  
Vol 234 (2) ◽  
pp. 347-357
Author(s):  
Jing Liu ◽  
Shizhao Ding ◽  
Linfeng Wang ◽  
Hongwu Li ◽  
Jin Xu
Keyword(s):  
Contact Stiffness ◽  
Planetary Gear ◽  
Gear Ratio ◽  
Gear System ◽  
Double Row ◽  
External Torque ◽  
Bearing Clearance ◽  
Gear Systems ◽  
Planetary Gear System ◽  
Stiffness And Damping

The bearing clearance, external torque, and input speed can greatly affect vibrations of the planetary gear system. The double-row planetary gear systems are commonly used in the gearbox of special vehicles, which are the key parts to obtain a larger gear ratio. Although many works have been presented to study those factors on vibrations of the single-row planetary gear system, a few works were focused on vibrations of the double-row planetary gear system with the bearing clearance. To overcome this problem, a multi-body dynamic model of a double-row planetary gear system with six planet bearings and one supported bearing of the sun gear is presented. This model is the main part of a gear box transmission system. The new model is developed for studying the effect of the bearing clearance on the planetary system. The meshing stiffness and damping between the gears are obtained by current methods in the listed references, as well as the contact stiffness and damping in bearings. The liner stiffness and damping model is used. The effects of the bearing clearance, external torque, and input speed on vibrations of the system are analyzed. The results show that vibrations of the ring gear and sun gear decrease with the increment of the external torque and increase with the increment of the input speed. Moreover, a reasonable bearing clearance can be helpful for reducing system vibrations for some mating external torque and input speed conditions. The results can provide some guidance to find new method to reduce vibrations and increase the service life of planetary gear systems.

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.

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