scholarly journals Analysis of the characteristics of electromechanical-hydraulic model of multi-source drive/transmission system based on periodic excitation

2019 ◽  
Vol 11 (1) ◽  
pp. 168781401881712
Author(s):  
Yang Yang ◽  
Yuquan Mi ◽  
Datong Qin ◽  
Aihui Yuan ◽  
Guowei Li
Keyword(s):  
Dynamic Characteristics ◽  
Coupling Model ◽  
Flow Speed ◽  
Transmission System ◽  
Drive System ◽  
Lumped Parameter Model ◽  
Time Varying ◽  
Flow Pulsation ◽  
Meshing Stiffness ◽  
Internal Excitation

Multi-source drive system with the feature of compact, small size and other advantages is widely used in large engineering machinery, such as shield machine, wind turbines, and shearer. In this article, a reasonable power transmission form is designed and the electromechanical-hydraulic coupling model of the multi-source drive system including the hydraulic pump-motor lumped parameter model and gear system dynamics model is established based on the co-simulation of MATLAB and AMEsim. Taking the pump flow pulsation and the time-varying meshing stiffness as the external and internal excitation of the multi-source drive system, respectively, the vibration and the dynamic characteristics of the multi-source drive system and the transfer characteristics of the dynamic excitation are analyzed. Results show that the flow-speed pulsation and the pressure-torque pulsation are gradually reduced along the direction of the transmission chain. As the external and internal excitation, the flow pulsation and the time-varying meshing stiffness will cause complex influences on the vibration and the dynamic characteristics of the multi-source transmission system. The findings provide a reference basis for the design of the multi-source drive system.

Research on dynamic characteristics of gear system considering the influence of temperature on material performance

2021 ◽  
pp. 107754632110026
Author(s):  
Zhou Sun ◽  
Siyu Chen ◽  
Xuan Tao ◽  
Zehua Hu
Keyword(s):  
Elastic Modulus ◽  
Dynamic Characteristics ◽  
Poisson’S Ratio ◽  
Gear System ◽  
Poisson's Ratio ◽  
Effect Of Temperature ◽  
Time Varying ◽  
Influence Of Temperature ◽  
Meshing Stiffness ◽  
Influence Of Temperature On

Under high-speed and heavy-load conditions, the influence of temperature on the gear system is extremely important. Basically, the current work on the effect of temperature mostly considers the flash temperature or the overall temperature field to cause expansion at the meshing point and then affects nonlinear factors such as time-varying meshing stiffness, which lead to the deterioration of the dynamic transmission. This work considers the effect of temperature on the material’s elastic modulus and Poisson’s ratio and relates the temperature to the time-varying meshing stiffness. The effects of temperature on the elastic modulus and Poisson’s ratio are expressed as functions and brought into the improved energy method stiffness calculation formula. Then, the dynamic characteristics of the gear system are analyzed. With the bifurcation diagram, phase, Poincaré, and fast Fourier transform plots of the gear system, the influence of temperature on the nonlinear dynamics of the gear system is discussed. The numerical analysis results show that as the temperature increases, the dynamic response of the system in the middle-speed region gradually changes from periodic motion to chaos.

scholarly journals Frequency and Vibration Characteristics of High-Speed Gear-Rotor-Bearing System with Tooth Root Crack considering Compound Dynamic Backlash

2019 ◽  
Vol 2019 ◽  
pp. 1-19 ◽  
Author(s):  
Jie Liu ◽  
Weiqiang Zhao ◽  
Weiwei Liu
Keyword(s):  
Time Domain ◽  
Crack Depth ◽  
Transmission System ◽  
Gear System ◽  
Time Varying ◽  
Tooth Root ◽  
Meshing Stiffness ◽  
The Time Domain ◽  
Center Distance ◽  
Root Crack

Considering the microstructure of tooth surface and the dynamic characteristics of the vibration responses, a compound dynamic backlash model is employed for the gear transmission system. Based on the fractal theory and dynamic center distance, respectively, the dynamic backlash is presented, and the potential energy method is applied to compute the time-varying meshing stiffness, including the healthy gear system and the crack fault gear system. Then, a 16-DOF coupled lateral-torsional gear-rotor-bearing transmission system with the crack fault is established. The fault characteristics in the time-domain waveform and frequency response and statistics data are described. The effect of crack on the time-varying meshing stiffness is analyzed. The vibration response of three backlash models is compared. The dynamic response of the system is explored with the increase in crack depth in detail. The results show that the fault features of countershaft are more obvious. Obvious fluctuations are presented in the time-domain waveform, and sidebands can be found in the frequency domain responses when the tooth root crack appears. The effect of compound dynamic backlash on the system is more obvious than fixed backlash and backlash with changing center distance. The vibration displacement along meshing direction and dynamic meshing force increases with the increase in crack depth. Backlash and variation of center distance show different tendencies with increasing crack depth under different rotational speeds. Amplitude of the sidebands increases with crack depth increasing. The amplitude of multiplication frequency of rotational frequency has an obvious variation with growing crack depth. The sidebands of the multiplication frequency of meshing frequency show more details on the system with complex backlash and crack fault.

Dynamic Simulation Analysis of Asymmetric Involute Gear Drive System

2012 ◽  
Vol 215-216 ◽  
pp. 974-977 ◽  
Author(s):  
Li Ming Lian ◽  
Gui Min Liu
Keyword(s):  
Dynamic Simulation ◽  
Dynamic Characteristics ◽  
Simulation Analysis ◽  
Dynamic Performance ◽  
Transmission System ◽  
Drive System ◽  
Gear Transmission ◽  
Gear Drive ◽  
Involute Gear ◽  
Gear Transmission System

The dynamic performance of asymmetric involute gear transmission system is analyzed by the MSC.ADAMS software during the paper. By comparative analyzed with the traditional dynamic characteristics of symmetrical involute straight gear transmission, it can be summarized that the asymmetric involute gear transmission system has better vibration characteristics in the course of transmission.

scholarly journals Research of Mechanical Resonance Analysis and Suppression Control Method of the Servo Drive System

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Wenli Li ◽  
Yongkang Liu ◽  
Shuaishuai Ge ◽  
Daming Liao
Keyword(s):  
Model Predictive Control ◽  
Predictive Control ◽  
Notch Filter ◽  
Drive System ◽  
Time Varying ◽  
Servo Drive ◽  
Mechanical Resonance ◽  
Meshing Stiffness ◽  
Transmission Mechanisms ◽  
Servo Drive System

Transmission mechanisms of the servo drive system are not a pure rigid body, and the existence of the elastic transmission mechanisms will make the system generate mechanical resonance. Aiming at mechanical resonance of the servo drive system, the resonance generation mechanism is analyzed, the four-mass model considering the time-varying meshing stiffness of the gear is established, and the influence of different stiffness parameters on the mechanical resonance of the system is researched in this paper. The composite controller of Model Predictive Control (MPC) with Notch Filter is used to simulate the mechanical resonance suppression of the four-mass servo system considering time-varying meshing stiffness, and it is compared with the mechanical resonance suppression method based on Model Predictive Control. The simulation results show that when the step speed is 200 r/min, the overshoot is reduced from 11.6 r/min to 1.1 r/min, which is reduced by 90.5%. Under the impact load condition, from 10 Nm to 30 Nm, overshoot is reduced from 34.3 r/min to 12.8 r/min, reduced by 62%, and torque oscillation is reduced by 81.5%. Therefore, the composite controller of Model Predictive Control with Notch Filter can suppress the mechanical resonance problem effectively, caused by elastic transmission, and improve the robustness of servo drive system.

scholarly journals Nonlinear characteristics of a multi-degree-of-freedom wind turbine’s gear transmission system involving friction

2021 ◽  
Author(s):  
Qiang Zhang ◽  
Xiaosun Wang ◽  
Shaobo Cheng ◽  
Fuqi Xie ◽  
Shijing Wu
Keyword(s):  
Excitation Frequency ◽  
Transmission System ◽  
Friction Model ◽  
Gear Transmission ◽  
Degree Of Freedom ◽  
Gear System ◽  
Time Varying ◽  
High Frequency Region ◽  
Meshing Stiffness ◽  
Gear Transmission System

Abstract In this study, a 42-degree-of-freedom (42-DOF) translation-torsion coupling dynamics model of the wind turbine’s compound gear transmission system considering time-varying meshing friction, timevarying meshing stiffness, meshing damping, meshing error and backlash is proposed. Considering the different meshing between internal and external teeth of planetary gear, the time-varying meshing stiffness is calculated by using the cantilever beam theory. An improved mesh friction model takes account into the mixing of elastohydrodynamic lubrication (EHL) and boundary lubrication to calculate the time-varying mesh friction. The bifurcation diagram is used to analyze the bifurcation and chaos characteristics of the system under the excitation frequency as bifurcation parameter. Meanwhile, the dynamic characteristics of the gear system are identified from the time domain diagrams, phase diagrams, Poincare maps and amplitude-frequency spectrums of the gear system. The results show that the system has complex bifurcation and chaotic behaviors including periodic, quasi-periodic, chaotic motion. The bifurcation characteristics of the system become complicated and the chaotic region increases considering the effects of friction in the high frequency region.

Investigation on Nonlinear Dynamic Characteristics of a New Rigid-Flexible Gear Transmission With Wear

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Zhibo Geng ◽  
Ke Xiao ◽  
Jiaxu Wang ◽  
Junyang Li
Keyword(s):  
Nonlinear Dynamic ◽  
Operating Time ◽  
Transmission System ◽  
Gear Transmission ◽  
Time Varying ◽  
Control Parameters ◽  
Nonlinear Dynamic Model ◽  
Meshing Stiffness ◽  
Gear Backlash ◽  
Gear Transmission System

Abstract At present, the mean value of the meshing stiffness and the gear backlash is a fixed value in the nonlinear dynamic model. In this study, wear is considered in the model of the gear backlash and time-varying stiffness. With the increase of the operating time, the meshing stiffness decreases and the gear backlash increases. A six degrees-of-freedom nonlinear dynamic model of a new rigid-flexible gear pair is established with time-varying stiffness and time-varying gear backlash. The dynamic behaviors of the gear transmission system are studied through bifurcation diagrams with the operating time as control parameters. Then, the dynamic characteristics of the gear transmission system are analyzed using excitation frequency as control parameters at four operating time points. The bifurcation diagrams, Poincaré maps, fast Fourier transform (FFT) spectra, phase diagrams, and time series are used to investigate the state of motion. The results can provide a reference for the gear transmission system with wear.

scholarly journals Analysis of dynamic characteristics of power split spiral bevel gear transmission system based on teeth geometric contact analysis

2019 ◽  
Vol 43 (1) ◽  
pp. 47-62 ◽  
Author(s):  
Hao Dong ◽  
Zhi-Yu Liu ◽  
Xiaolong Zhao ◽  
Ya-Hui Hu
Keyword(s):  
Dynamic Characteristics ◽  
Dynamic Load ◽  
Power Flow ◽  
Transmission System ◽  
Contact Analysis ◽  
Bevel Gear ◽  
Time Varying ◽  
Gear Pair ◽  
Vibration Acceleration ◽  
Power Split

To solve the dynamic load distribution mechanism of the power split transmission system of spiral bevel gears, according to the characteristics of the closed loop of power flow, the deformation coordination condition is deduced. Through the gear teeth geometric contact analysis technique, the time-varying meshing stiffness conditions in the model are solved. The linear time-varying dynamic model of the torsional vibration of the bevel gear split transmission system is established by the lumped mass parameter method. Considering the influence of time-varying mesh stiffness excitation conditions and damping, the dynamic differential equations are treated in a dimensionless way. The dynamic load change and dynamic response characteristics of the system are obtained by numerical solution, and the influence of parameters such as speed and damping on dynamic power flow and dynamic characteristics of the system is revealed. The results show that with an increase of meshing damping ratio, dynamic power flow of each gear pair changes little, and the vibration acceleration and its root mean square value of each gear pair of the system are smaller. With an increase in speed, vibration acceleration and its average amplitude increase.

Dynamic Analysis of Offset Printing Press Gear-Cylinder-Bearing System under Time-Varying Meshing Stiffness Effect

2015 ◽  
Vol 656-657 ◽  
pp. 658-663
Author(s):  
Tian Cheng Ou Yang ◽  
Nan Chen ◽  
Cui Cui Ju ◽  
Cheng Long Li ◽  
Jiang Hu Li
Keyword(s):  
Equations Of Motion ◽  
Transmission System ◽  
Gear Transmission ◽  
Printing Press ◽  
Time Varying ◽  
Offset Printing ◽  
Meshing Stiffness ◽  
Lumped Parameter ◽  
Gear Transmission System ◽  
Bearing System

This study propose a new nonlinear model for offset printing press gear-cylinder-bearing system by the lumped parameter approach. The multi-DOF model consists of helical gear pairs and spur gear pairs with time-varying meshing stiffness. Bearing and shaft flexibilities are include in the model as well. The equations of motion are obtained by Darren Bell principle and Runge-Kutta numerical method is used to slove the equations of motion. The results show that meshing stiffness and bearing stiffness significantly affect critical speed, vibration acceleration and meshing force. Multi-body dynamics software are applied to compare with lumped parameter model. The results show that there are many similarities in different aspects. Results of experimental study on offset printing press are also presented for validation of different models. After Discrete Fourier Transform, the graphics display that acceleration peaks frequencies are an integer multiple of the gear mesh frequency. It demonstrate that mechanical vibration is mainly from gear transmission system at high printing speed and gear transmission system lead to nonlinear vibration. This work provide a foundation for further improvement of the dynamics of gear system.

scholarly journals The Analysis and Modeling of the Synthetical Meshing Stiffness of Inner Gearing considering the Flexible Inner Ring Gear

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Shengyang Hu ◽  
Zongde Fang
Keyword(s):  
Planetary Gear ◽  
Element Model ◽  
Transmission System ◽  
Lumped Parameter Model ◽  
Ring Gear ◽  
Gear Teeth ◽  
Meshing Stiffness ◽  
Lumped Parameter ◽  
Sectional Shape ◽  
The Finite Element Model

As a key part of vibration generation and transmission of planetary gear transmissions, thin-walled inner ring gear deforms under the influence of meshing excitation and seriously affects the reliability and fatigue life of the transmission system. The effect of the flexibility of the inner ring gear on the transmission system is ignored in the calculation of making the inner ring gear as a rigid body in the lumped parameter model, while the calculation amount of the finite element model is too large. Therefore, it is very important to establish an accurate and reasonable model to solve the flexibility of the inner ring gear. In this paper, according to the supporting mode, supporting quantity, thickness, and sectional shape of the inner ring gear, the inner ring gear is reasonably separated into the form of multisection curved beam. The displacement of the gear teeth in the meshing line caused by the flexibility of the inner ring gear is obtained rapidly and accurately. It lays an important theoretical foundation for the dynamic analysis of planetary gear transmission.

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