scholarly journals Analysis of Dynamic Characteristics of the Multistage Planetary Gear Transmission System with Friction Force

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Zhengming Xiao ◽  
Fu Chen ◽  
Kongliang Zhang
Keyword(s):  
Planetary Gear ◽  
Transmission System ◽  
Gear Transmission ◽  
Dynamical Model ◽  
Tooth Surface ◽  
Time Varying ◽  
Two Stage ◽  
Friction Coefficients ◽  
Planetary Gearbox ◽  
Gear Transmission System

Multistage planetary gear transmission system has been widely utilized in engineering practice due to the salient characteristics, such as high bearing load and large speed ratio. This paper addresses a two-stage planetary gearbox and establishes a system coupling torsional dynamical model which considers the time-varying mesh stiffness, friction forces, and interstage coupling factors. Meanwhile, the friction and lubrication states are classified to comprehensively analyze the calculation of friction coefficients under different conditions. Considering the time-varying influence of friction on the tooth surface under the condition of fluid lubrication, the vibration response under parametric excitation is solved by a numerical method. A multistage planetary transmission test bench is built in the back-to-back form so as to test the vibration of the two-stage planetary gearbox. It shows that the simulation results of the dynamical model are consistent with the test data. Consideration of the calculation of friction on the tooth surface and the friction coefficients is helpful for the establishment of the more accurate dynamical model and lays the foundation for the structural design, fault diagnosis, and dynamic optimization of the multistage planetary gear transmission system.

Optimal Design of Gear Transmission System of Increasing Speed for Half-Direct-Drive Tidal Current Energy Station

2010 ◽  
Vol 450 ◽  
pp. 345-348 ◽  
Author(s):  
Fan Kai Kong ◽  
Su Ge Yin ◽  
Hong Yun Lin ◽  
Qi Hu Sheng
Keyword(s):  
Genetic Algorithm ◽  
Tidal Current ◽  
Planetary Gear ◽  
Transmission System ◽  
Gear Transmission ◽  
Direct Drive ◽  
Tidal Current Energy ◽  
Planetary Gearbox ◽  
Gear Transmission System ◽  
Mixed Genetic Algorithm

The half-direct-drive transmission is conducted for the transmission system of tidal current power stations using a small speed-up ratio of planetary gearbox between turbine and generator. A design model is developed for the optimization of the planetary gear transmission system. And a mixed genetic algorithm is applied on the basis of fundamentals of genetic algorithm to carry out the optimization. From the example calculation, a better design scheme is obtained by the optimization.

Modelling and modal analysis of a hoist equipped with two-stage planetary gear transmission system

2016 ◽  
Vol 231 (4) ◽  
pp. 739-749 ◽  
Author(s):  
Wei Yang ◽  
Xiaolin Tang
Keyword(s):  
Modal Analysis ◽  
Natural Frequencies ◽  
Planetary Gear ◽  
Transmission System ◽  
Gear Transmission ◽  
Gear Train ◽  
Contact Method ◽  
Two Stage ◽  
Gear Transmission System ◽  
Viscoelastic Contact

The connection between a gear pair is commonly treated as constant stiffness in the literature of planetary gear transmission dynamics, leading to inaccurate results. Based on the theory of viscoelastic contact, according to low speed or stationary gear pairs have the characteristics of small relative sliding velocity, viscoelastic contact method is proposed to solve this problem. A hoist equipped with two-stage planetary gear reducer is used as research object to investigate the dynamic properties. The natural frequencies and corresponding vibration modes of this planetary gear transmission system are presented. Accordingly, the natural frequencies are recognized using operational modal analysis under ambient excitation, and the experimental studies are in close agreement with theoretical expectation. In addition, the dynamic behaviours of this planetary gear train are investigated.

scholarly journals Study on Dynamics of a Two-Stage Gear Transmission System with and without Tooth Breakage

Processes ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 2141
Author(s):  
Deyi Fu ◽  
Shiqiao Gao ◽  
Haipeng Liu
Keyword(s):  
Numerical Simulation ◽  
Periodic Motion ◽  
Domain Analysis ◽  
Transmission System ◽  
Gear Transmission ◽  
Time Varying ◽  
Two Stage ◽  
Meshing Stiffness ◽  
Vibration Condition ◽  
Gear Transmission System

This paper studies the dynamics of a two-stage gear transmission system in both the normal state and the fault state with tooth breakage. The torsional vibration model of the two-stage parallel shaft gear was developed by using the lumped parameter method. The time-varying meshing stiffness of the gear transmission system is described by Fourier series which is determined by the periodical meshing characteristics of the gears with both the single-tooth and the double-tooth contacts. By introducing the pulse into the regular time-varying meshing stiffness, the tooth breakage existing in the gear transmission system is mimicked. Based on the numerical simulation of the developed dynamic model, both the time domain analysis and the frequency domain analysis of the gear transmission system under both the normal condition and the tooth breakage are compared accordingly. The influence of the tooth breakage on the dynamic characteristics of the gear transmission system is analyzed comprehensively. Furthermore, based on the developed test bench of a two-stage gear transmission system, the experimental research was carried out, and the experimental results show great agreements with the results of numerical simulation, and thus the validity of the developed mathematical model is demonstrated. By comparing the periodic motion with the chaotic motion, the fault identification for the gear transmission system is verified to be tightly related to its vibration condition, and the control of the vibration condition of the gear transmission system as periodic motion is of great significance to the fault diagnosis.

scholarly journals A Coupling Dynamics Analysis Method for Two-Stage Spur Gear under Multisource Time-Varying Excitation

2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Zizhen Qiao ◽  
Jianxing Zhou ◽  
Wenlei Sun ◽  
Xiangfeng Zhang
Keyword(s):  
Dynamic Response ◽  
Spur Gear ◽  
Frequency Component ◽  
Transmission System ◽  
Gear Transmission ◽  
Mode Shapes ◽  
Time Varying ◽  
Two Stage ◽  
Gear Transmission System ◽  
Shaft Flexibility

A new modeling method is proposed to simulate the dynamic response of a two-stage gear transmission system using the finite element method (FEM). The continuous system is divided into four modules: shaft-shaft element, shaft-gear element, shaft-bearing element, and gear-gear element. According to the FEM, the model is built with each element assembled. Meanwhile, the model considers the time-varying mesh stiffness (TVMS), bearing time-varying stiffness (BTVS), and the shaft flexibility. The Newmark integration method (NIM) is used to obtain the dynamic response of the spur gear system. Results show that vibration amplitude and the number of frequency components decrease after considering shaft flexibility through comparing the gear dynamic response under the condition of flexible shaft and rigid shaft. When the effect of bearing stiffness is considered, there will be a bearing passing frequency component in the frequency spectrum. In addition, the result shows that the simulation and experimental test of the frequency component are basically consistent. Furthermore, the theoretical model is validated against an experimental platform of the two-stage gear transmission system and the dynamic responses are compared under the condition of increasing speed. Additionally, the increase of shaft stiffness not only changes some of the dominant mode shapes (torsional mode shapes) but also makes the number of primary resonance speeds added. The method can be used to guide the design of gear systems.

scholarly journals Dynamic characteristics analysis of planetary gear system with internal and external excitation under turbulent wind load

2021 ◽  
Vol 104 (3) ◽  
pp. 003685042110356
Author(s):  
Hexu Yang ◽  
Xiaopeng Li ◽  
Jinchi Xu ◽  
Zemin Yang ◽  
Renzhen Chen
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Nonlinear Dynamic ◽  
Planetary Gear ◽  
Wind Load ◽  
Transmission System ◽  
Gear Transmission ◽  
Stiffness Ratio ◽  
Gear Transmission System ◽  
Planetary Gear System

According to the working characteristics of a 1.5 MW wind turbine planetary gear system under complex and random wind load, a two-parameter Weibull distribution model is used to describe the distribution of random wind speed, and the time-varying load caused by random wind speed is obtained. The nonlinear dynamic model of planetary gear transmission system is established by using the lumped parameter method, and the relative relations among various components are derived by using Lagrange method. Then, the relative relationship between the components is solved by Runge Kutta method. Considering the influence of random load and stiffness ratio on the planetary gear transmission system, the nonlinear dynamic response of cyclic load and random wind load on the transmission system is analyzed. The analysis results show that the variation of the stiffness ratio makes the planetary gear have abundant nonlinear dynamics behavior and the planetary gear can get rid of chaos and enter into stable periodic motion by changing the stiffness ratio properly on the premise of ensuring transmission efficiency. For the variable pitch wind turbine, the random change of external load increases the instability of the system.

scholarly journals Nonlinear Dynamic Analysis and Optimization of Closed-Form Planetary Gear System

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Qilin Huang ◽  
Yong Wang ◽  
Zhipu Huo ◽  
Yudong Xie
Keyword(s):  
Differential Equations ◽  
Closed Form ◽  
Dynamic Model ◽  
Total Mass ◽  
Nonlinear Differential Equations ◽  
Equations Of Motion ◽  
Planetary Gear ◽  
Transmission System ◽  
Gear Transmission ◽  
Gear Transmission System

A nonlinear purely rotational dynamic model of a multistage closed-form planetary gear set formed by two simple planetary stages is proposed in this study. The model includes time-varying mesh stiffness, excitation fluctuation and gear backlash nonlinearities. The nonlinear differential equations of motion are solved numerically using variable step-size Runge-Kutta. In order to obtain function expression of optimization objective, the nonlinear differential equations of motion are solved analytically using harmonic balance method (HBM). Based on the analytical solution of dynamic equations, the optimization mathematical model which aims at minimizing the vibration displacement of the low-speed carrier and the total mass of the gear transmission system is established. The optimization toolbox in MATLAB program is adopted to obtain the optimal solution. A case is studied to demonstrate the effectiveness of the dynamic model and the optimization method. The results show that the dynamic properties of the closed-form planetary gear transmission system have been improved and the total mass of the gear set has been decreased significantly.

Dynamical Analysis of Planetary Gear Transmission System Under Support Stiffness Effects

2020 ◽  
Vol 30 (06) ◽  
pp. 2050080
Author(s):  
Ling Xiang ◽  
Zeqi Deng ◽  
Aijun Hu
Keyword(s):  
Excitation Frequency ◽  
Global Bifurcation ◽  
Planetary Gear ◽  
Transmission System ◽  
Gear Transmission ◽  
Dynamic Responses ◽  
Dynamical Analysis ◽  
Largest Lyapunov Exponent ◽  
Meshing Stiffness ◽  
Gear Transmission System

The transverse-torsional nonlinear model of multistage gear transmission system which is comprised of a planetary gear set and two parallel gear stages is proposed with time-varying meshing stiffness, comprehensive gear errors and gear backlash. The nonlinear dynamic responses are analyzed by applying excitation frequency and support stiffness as the bifurcation parameters. The motions of the system are identified through global bifurcation diagram, largest Lyapunov exponent (LLE) and Poincaré map. The numerical results demonstrate that the support stiffness affects the system, especially on planetary gear set. The motions of the system with the changes of the support stiffness are diverse including some different multiperiodic motions. Also, the state of the system undergoes 2T-periodic motion, chaos, quasi-periodic behavior and multiperiodic motion. For the support stiffness or other nonlinear factors of the gear system, the suitable range of working frequencies could make the system stable. Correspondingly, parameters of the system should be designed properly and controlled for the better operation and enhancing the life of the system.

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