scholarly journals Effects of ranging arm housing’s large deformation on the dynamic responses of the cutting transmission system for a drum shearer

2019 ◽  
Vol 11 (4) ◽  
pp. 168781401984436 ◽  
Author(s):  
Hanjie Jia ◽  
Datong Qin
Keyword(s):  
Large Deformation ◽  
Transmission System ◽  
Dynamic Responses ◽  
Drum Shearer

Nonlinear dynamic response analysis on gear-rotor-bearing transmission system

2016 ◽  
Vol 24 (9) ◽  
pp. 1632-1651 ◽  
Author(s):  
Shihua Zhou ◽  
Guiqiu Song ◽  
Mengnan Sun ◽  
Zhaohui Ren
Keyword(s):  
Friction Coefficient ◽  
Friction Force ◽  
Nonlinear Dynamic ◽  
Nonlinear Differential Equations ◽  
Transmission System ◽  
Dynamic Responses ◽  
Response Analysis ◽  
Light Load ◽  
Rotor Bearing ◽  
The Mean

A coupled lateral-torsional nonlinear dynamic model with 16-degree-of-freedom (16-DOF) of gear-rotor-bearing transmission system (GRBTS) is developed after comprehensive considering the nonlinear features associated with time-varying meshing stiffness, backlash, transmission error, friction force, input/output load, gravity and gear eccentricity. Based on the nonlinear differential equations, the coupled multi-body dynamic responses of the GRBTS are demonstrated using the Runge-Kutta numerical method, and the effects of friction coefficient and mean load on the dynamic characteristics are investigated. The results show that the friction force could enlarge the vibration amplitude and affect the low frequency components seriously. The mean load excitation has a complicated influence on the coupled GRBTS, and the torsional vibration is the dominate response. Whereas the mean load excitation has a certain extent vibration suppression, and light load and heavy load could no longer effectively control the nonlinear vibration of the GRBTS. With the increasing of rotational speed, the friction coefficient and mean load ranges of the chaotic behavior widen and the chaotic characteristics strengthens. It is shown that small parameter random perturbation might be propagated in the vibration system and lead to relatively large vibration of the system. The contribution to provide a reference for the design and study of gear system.

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.

Dynamic responses and control of geared transmission system based on multibody modeling methodology

2022 ◽  
pp. 107754632110495
Author(s):  
ZhaoYuan Yao ◽  
JunGuo Wang ◽  
YongXiang Zhao
Keyword(s):  
Control Method ◽  
Control Strategies ◽  
Joint Stiffness ◽  
Transmission System ◽  
Dynamic Responses ◽  
Linear Feedback ◽  
Friction Damper ◽  
Multibody Modeling ◽  
Modeling Methodology ◽  
Bearing System

In this study, an innovative modeling approach is put forward to research the effect of eccentricity on the nonlinear dynamical behaviors of geared-bearing system. This refined model contains the rigid body of the rotor-bearing system and separated gear teeth which are considered as individual bodies elastically attached to the gear hub with revolute joints. The internal and external excitations of the proposed model include torsional joint stiffness, roll bearing forces, friction between gear pair, gear eccentricity, and so on. The systematic procedure for the calculation of torsional joint stiffness, bearing forces and friction coefficient considering elastohydrodynamic is also conducted. After that, the influence of eccentricity on nonlinear dynamic characteristics of the geared transmission system is analyzed. To avoid the system moving in the unstable motion state, a dry friction damper controller is designed to control the nonlinear behaviors simulated on the basis of above model. The linear feedback and periodic excitation non-feedback control strategies are, respectively, selected to design the actuator. It is indicated that undesirable behaviors of the geared transmission system can be avoided effectively by applying the proposed control method.

Effects of gearbox housing flexibility on dynamic characteristics of gear transmission system

2020 ◽  
pp. 107754632095373
Author(s):  
Xiannian Kong ◽  
Jinyuan Tang ◽  
Chen Siyu ◽  
Zehua Hu
Keyword(s):  
Dynamic Analysis ◽  
Natural Frequencies ◽  
Lightweight Design ◽  
Transmission System ◽  
Structure Design ◽  
Gear Transmission ◽  
Dynamic Responses ◽  
Dynamic Behaviors ◽  
Gear Transmission System ◽  
Rotor Bearing

The lightweight design of the gear system is the current tendency. The gearbox housing is modeled as a rigid body and is neglected in the gear dynamic analysis. It is of great significance to introduce the gearbox housing flexibility into the dynamic analysis and analyze the influence of the gearbox housing flexibility on the dynamic behaviors of the gear transmission system, as this can provide important instructions for the lightweight structure design of the housing. The gear–rotor–bearing model and the gear–rotor–bearing–housing model are established by the finite element node method. A Timoshenko beam element is used to represent the shafts. To illustrate the housing effect, two kinds of housing model are established: one tends to be rigid and the other to be flexible and lighter. The housings are simplified as a super element obtained by the dynamic substructure method. Natural frequencies and dynamic responses are illustrated to indicate the effects of housing flexibility. Comparisons of numerical results show that the rigid housing can be neglected for its little effect on the dynamic analysis. The flexibility of the housing slightly reduces the natural frequencies of the gear transmission system, and the maximum reduction is 6.05%. Meanwhile, the amplitudes of the first two resonance peaks of the dynamic transmission error decrease by 9.5% and 5.05%. Besides, more response peaks emerge at higher speeds when the flexibility of housing increases. The complete phenomena of dynamic behaviors of the gear transmission system can be obtained by considering the housing flexibility.

scholarly journals Dynamic characteristics of a high-speed train gearbox in the vehicle–track coupled system excited by wheel defects

2019 ◽  
Vol 234 (10) ◽  
pp. 1210-1226 ◽  
Author(s):  
Zhiwei Wang ◽  
Paul Allen ◽  
Guiming Mei ◽  
Zhonghui Yin ◽  
Yao Cheng ◽  
...  
Keyword(s):  
High Speed ◽  
Dynamic Stress ◽  
Three Dimensional ◽  
Coupled System ◽  
Transmission System ◽  
Dynamic Responses ◽  
Connected Components ◽  
Dynamics Model ◽  
High Speed Trains ◽  
Polygonal Wear

To analyse and simulate the dynamic responses of the gearbox in a vehicle–track system, a three-dimensional vehicle–track coupled dynamics model for high-speed trains has been developed in this study with a comprehensive consideration of the transmission system. Using this dynamics model, the coupling effects between the gearbox housing and its connected components were analysed. Based on the dynamic results, the dynamic stress field of the gearbox housing can be obtained using the finite element methods. The model outputs were successfully validated through comparisons with field test data. Following model validation, the dynamic stress and its distribution throughout the gearbox housing were further investigated under different excitations, including track irregularities, wheel polygonal wear and flatness. The results demonstrate a significant increase in the stress levels of the oil level window aperture and the bottom face of the housing, which coincides with the location of cracks that are formed in the gearbox housing during frequent vehicle operation. While a specific case has been studied here, the proposed dynamics model can be applied to related dynamic assessments, such as vibration or suspension parameter analyses, as well as to stress analyses of any rail vehicle transmission system to guide the maintenance and design.

Periodic and Chaotic Dynamic Responses of Face Gear Transmission System

2013 ◽  
Vol 834-836 ◽  
pp. 1273-1280
Author(s):  
Ze Hua Hu ◽  
Jin Yuan Tang ◽  
Si Yu Chen
Keyword(s):  
Periodic Motion ◽  
Chaotic Dynamic ◽  
Rotational Frequency ◽  
Transmission System ◽  
Gear Transmission ◽  
Dynamic Responses ◽  
Time Varying ◽  
Mesh Stiffness ◽  
Face Gear ◽  
Gear Transmission System

The periodic and chaotic dynamic responses of face gear transmission system considering time-varying mesh stiffness and backlash nonlinearity are studied. Firstly, a nonlinear time-varying dynamic model of face gear pair is developed and the motion equations are presented, the real accurate mesh stiffness is obtained by applying Finite element approach. Then, the dynamic equations are solved using Runge-Kutta numerical integral method and bifurcation diagrams are presented and analyzed. The stability properties of steady state responses are illustrated with Floquet multipliers and Lyapunov exponents. The results show that a process of periodic-chaotic-periodic motion exists with the dimensionless pinion rotational frequency as control parameters. The analysis can be a reference to avoid the chaotic motion and unstable periodic motion through choosing suitable rotational frequency.

Analysis on the vibration reduction for a new rigid–flexible gear transmission system

2021 ◽  
pp. 107754632110132
Author(s):  
Zhibo Geng ◽  
Junyang Li ◽  
Ke Xiao ◽  
Jiaxu Wang
Keyword(s):  
Dynamic Model ◽  
Vibration Reduction ◽  
Surface Friction ◽  
Transmission System ◽  
Gear Transmission ◽  
Dynamic Responses ◽  
Gear Pair ◽  
Nonlinear Dynamic Model ◽  
Gear Transmission System ◽  
Flexible Gear

In this study, a new rigid–flexible gear with metal rubber is proposed to reduce the vibration of the gear transmission system. A nonlinear dynamic model with nine degrees of freedom considering bearing clearance, gear backlash, surface friction, and time-varying meshing stiffness is established. The nondimensional dynamic model of the transmission system is obtained and the bifurcation characteristics of the new rigid–flexible gear pair and the rigid gear pair are analyzed when the damping coefficient is, respectively, 0.03 and 0.1. The result shows that the motion state of the rigid–flexible gear pair is more stable. The dynamic responses of the rigid gear pair and the rigid–flexible gear pair are compared as well through numerical analysis and experiment to illustrate the advantage of the rigid–flexible gear pair in vibration reduction. The results can provide reference for vibration reduction of the novel gear transmission.

scholarly journals Nonlinear Torsional Dynamics of Star Gearing Transmission System of GTF Gearbox

2020 ◽  
Vol 2020 ◽  
pp. 1-15 ◽  
Author(s):  
Siyu Wang ◽  
Rupeng Zhu
Keyword(s):  
Nonlinear Dynamic ◽  
Damping Ratio ◽  
Global Bifurcation ◽  
Period Doubling ◽  
Transmission System ◽  
Dynamic Responses ◽  
Nonlinear Dynamic Model ◽  
Chaotic Motions ◽  
Meshing Stiffness ◽  
And Control

Considering time-varying meshing stiffness, comprehensive errors, and piecewise backlash nonlinearities of gear and spline, a torsional nonlinear dynamic model of star gear-rotor coupling transmission system of (Geared Turbofan Engine) GTF aeroengine is established. By using the Runge–Kutta numerical integration method, the dynamic responses are solved, analyzed, and illustrated with the bifurcation parameters including input rotational speed, gear backlash, damping ratio, and comprehensive meshing errors. The motions of the star gearing system and diverse nonlinear dynamic characteristics are identified through global bifurcation, FFT spectra, Poincaré map, and the phase diagram. The results reveal that the star gear-rotor system exhibits abundant torsional nonlinear behaviors, including multiperiodic, quasi-periodic, and chaotic motions. Furthermore, the roads to chaos via quasi-periodicity, period-doubling scenario, and mutation are demonstrated. These results provide an understanding of undesirable torsional dynamic motion for the GTF transmission system and provide a reference for the design and control of gear system.

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