scholarly journals Dynamic Modeling and Vibration Characteristics Analysis of Transmission Process for Dual-Motor Coupling Drive System

Symmetry ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1171
Author(s):  
Wei Fan ◽  
Yongfei Yang ◽  
Xiangang Su
Keyword(s):  
Dynamic Model ◽  
Electric Vehicles ◽  
Dynamic Characteristics ◽  
Low Frequency ◽  
Planetary Gear ◽  
Drive System ◽  
Dynamic Responses ◽  
Effective Control ◽  
Analysis Method ◽  
Transmission Process

The dual-motor coupling drive system (DCDS), which is widely used in electric vehicles, has attracted increasing attention due to its high transmission efficiency and economical fuel consumption. Current research has mainly focused on the control scheme of dual motors and has ignored the dynamic characteristics of the asymmetrical transmission structure. This paper presents an investigation of a dynamic model and an analysis method of the transmission process for the DCDS. The entire dynamic model of the DCDS was established by considering the planetary gear, differential bevel gear, and drive shaft with the transfer matrix method (TMM). Then, a detailed theoretical analysis was developed to study the influence of meshing stiffness and excitation source on the dynamic characteristics. Finally, the DCDS experimental platform was utilized to validate the effectiveness of the proposed dynamic model. For susceptibility to low-frequency vibrations, the first four natural frequencies and vibration modes of the DCDS were analyzed through the processing and analysis of acceleration signals. The experimental dynamic responses were generally consistent with the numerically computed results, which demonstrates the effectiveness of the proposed dynamic model with TMM. Furthermore, the proposed dynamic analysis method may be helpful for developing effective control algorithms to suppress vibrations and achieving highly smooth motions for electric vehicles.

Dynamics of the Gear Train Set in Wind Turbine

2011 ◽  
Vol 697-698 ◽  
pp. 701-705
Author(s):  
D.D. Ji ◽  
Y.M. Song ◽  
J. Zhang
Keyword(s):  
Wind Turbine ◽  
Dynamic Model ◽  
Harmonic Balance Method ◽  
Planetary Gear ◽  
Gear Train ◽  
Dynamic Responses ◽  
Multi Stage ◽  
Lumped Parameter ◽  
Cartesian Coordinate ◽  
The Impact

A lumped-parameter dynamic model for gear train set in wind turbine is proposed to investigate the dynamics of the speed-increasing gear box. The proposed model is developed in a universal Cartesian coordinate, which includes transversal and torsional deflections of each component, time-varying mesh stiffness, gear profile errors and external excitations. By solving the dynamic model, a modal analysis is performed. The results indicate that the modal properties of the multi-stage gear train in wind turbine are similar to those of a single-stage planetary gear set. A harmonic balance method (HBM) is used to obtain the dynamic responses of the gearing system. The responses give insight into the impact of excitations on the vibrations.

scholarly journals Dynamic Characteristics Analysis with Multi-Directional Coupling in a TBM Mainframe

2019 ◽  
Vol 32 (1) ◽  
Author(s):  
Laikuang Lin ◽  
Yimin Xia ◽  
Zhengguang Li ◽  
Caizhang Wu ◽  
Yongliang Cheng ◽  
...  
Keyword(s):  
Dynamic Model ◽  
Dynamic Characteristics ◽  
Field Tests ◽  
Fatigue Cracking ◽  
Tunnel Boring Machine ◽  
Dynamic Responses ◽  
Water Diversion ◽  
Practical Significance ◽  
Lumped Mass ◽  
Response Characteristics

AbstractThe cutterhead of a full-face rock tunnel boring machine (TBM) is constantly subjected to varying impact and dynamic loads during tunneling processes, resulting in relatively large vibrations that could easily lead to fatigue cracking of the entire machine and affect the tunneling performance and efficiency. To explore the dynamic characteristics of the TBM mainframe, a TBM from a water-diversion project is investigated in this research. According to the TBM vibration transmission route, an equivalent dynamic model of the TBM mainframe is established using the lumped-mass method in which the relevant dynamic parameters are solved. Additionally, the dynamic response characteristics of the TBM mainframe are analyzed. The results indicate that the vibration levels in three directions are approximately the same, the multi-directional vibration of the cutterhead is more intense than that of other components, and the vibration and external excitation exhibit identical change trends. A set of vibration field tests is performed to analyze the in situ dynamic responses of the mainframe and verify the correctness of the dynamic model. The theoretical and measured acceleration values of the TBM mainframe have the same magnitude, which proves the validity of the dynamic model and its solution. The aforementioned results provide an important theoretical value and practical significance for the design and assessment of the TBM mainframe.

Dynamic Analysis of Helical Planetary Gear Train

2013 ◽  
Vol 404 ◽  
pp. 312-317 ◽  
Author(s):  
Xian Zeng Liu ◽  
Jun Zhang
Keyword(s):  
Steady State ◽  
Free Vibration ◽  
Dynamic Model ◽  
Planetary Gear ◽  
Gear Train ◽  
Dynamic Responses ◽  
Design Parameters ◽  
Planetary Gear Train ◽  
State Dynamic ◽  
The Impact

A dynamic model for helical planetary gear train (HPGT) is proposed. Based on the model, the free vibration characteristics, steady-state dynamic responses and effects of design parameters on system dynamics are investigated through numerical simulations. The free vibration of the HGPT is classified into 3 categories. The classified vibration modes are demonstrated as axial translational and torsional mode (AT mode), radial translational and rotational mode (RR mode) and planet mode (P mode) followed by the characteristics of each category. The simulation results agree well with those of previous discrete model when neglecting the component flexibilities, which validates the correctness of the present dynamic model. The steady-state dynamic responses indicate that the dynamic meshing forces fluctuate about the average static values and the time-varying meshing stiffness is one of the major excitations of the system. The parametric sensitivity analysis shows that the impact of the central component bearing stiffness on the dynamic characteristic of the HPGT system is significant.

Modeling and Dynamic Characteristics of Planetary Gear Transmission in Non-inertial System of Aerospace Environment

2019 ◽  
Vol 142 (3) ◽  
Author(s):  
Jing Wei ◽  
Aiqiang Zhang ◽  
Lei Shi ◽  
Datong Qin ◽  
Teik C. Lim
Keyword(s):  
Dynamic Behavior ◽  
Dynamic Characteristics ◽  
Planetary Gear ◽  
Gear Transmission ◽  
Dynamic Responses ◽  
Inertial System ◽  
Dominant Factor ◽  
Central Component ◽  
Traditional Research ◽  
Planet Gear

Abstract The traditional research on the dynamics of planetary gear transmission (PGT) is based on the assumption that the support is on the ground. However, the PGT inside the aircraft is spatially moved along with the airframe, which is not only subject to gravity, but also to additional inertia forces. These loads should affect the dynamic characteristics of the PGT. The PGT itself is a non-inertial system (NIS) and is called the internal non-inertial system (INIS). By contrast, an airframe in the aerospace environment is named an external non-inertial system (ENIS). In order to investigate the dynamic behavior of the PGT in a compound NIS, the kinematic equations of various components in arbitrary spatial motion state of the airframe are deduced. Subsequently, the coupled dynamics model of PGT in NIS is improved. The dynamic responses of PGT in different non-inertial conditions are compared based on the hovering motion of the airframe. The results indicate that INIS is the main factor affecting the trajectory of planet gear, while ENIS is the force source changing the trajectory of the central component. The aircraft’s hovering motion makes the gravity effect become a relatively time-varying excitation, but the dominant factor is still the additional inertial forces. The non-inertial effect during aerospace operation can significantly affect the bearing force, vibration and load sharing performance. It will lead to serious errors if the traditional research method is still used to obtain the dynamic behavior of PGT in the aerospace environment.

Dynamic Analysis and Optimization for Wafer Handling Robot

2014 ◽  
Vol 898 ◽  
pp. 657-662
Author(s):  
Ming Yue Wu ◽  
Yan Jie Liu ◽  
He Gao Cai
Keyword(s):  
Dynamic Analysis ◽  
Dynamic Model ◽  
Natural Frequency ◽  
Dynamic Optimization ◽  
Dynamic Characteristics ◽  
Low Frequency ◽  
Numerical Procedure ◽  
Optimization Result

Aiming at suppressing the vibration of low-frequency, a procedure of dynamic optimization of wafer handling robot is presented. The dynamic model of wafer handling robot is firstly build, and following that the dynamic characteristics of the robot are analyzed to find the main parameters which will influence the natural frequency. Then, the numerical procedure of the optimization of the natural frequency is introduced, and the constraint functions are obtained by considering the workspace and the structure of the robot. And at the end, as a case study, the procedure is applied to a wafer handling robot. Optimization result shows that the natural frequency is enhanced to 32.56Hz after the optimization.

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.

Application of the piecewise constant method in nonlinear dynamics of drill string

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jialin Tian ◽  
Jie Wang ◽  
Yi Zhou ◽  
Lin Yang ◽  
Changyue Fan ◽  
...  
Keyword(s):  
Nonlinear Dynamics ◽  
Dynamic Model ◽  
Dynamic Characteristics ◽  
Drill String ◽  
Vibration Velocity ◽  
Kutta Method ◽  
Time Step ◽  
Piecewise Constant ◽  
Runge Kutta Method ◽  
Runge Kutta

Abstract Aiming at the current development of drilling technology and the deepening of oil and gas exploration, we focus on better studying the nonlinear dynamic characteristics of the drill string under complex working conditions and knowing the real movement of the drill string during drilling. This paper firstly combines the actual situation of the well to establish the dynamic model of the horizontal drill string, and analyzes the dynamic characteristics, giving the expression of the force of each part of the model. Secondly, it introduces the piecewise constant method (simply known as PT method), and gives the solution equation. Then according to the basic parameters, the axial vibration displacement and vibration velocity at the test points are solved by the PT method and the Runge–Kutta method, respectively, and the phase diagram, the Poincare map, and the spectrogram are obtained. The results obtained by the two methods are compared and analyzed. Finally, the relevant experimental tests are carried out. It shows that the results of the dynamic model of the horizontal drill string are basically consistent with the results obtained by the actual test, which verifies the validity of the dynamic model and the correctness of the calculated results. When solving the drill string nonlinear dynamics, the results of the PT method is closer to the theoretical solution than that of the Runge–Kutta method with the same order and time step. And the PT method is better than the Runge–Kutta method with the same order in smoothness and continuity in solving the drill string nonlinear dynamics.

scholarly journals The Structure and Optimal Gear Tooth Profile Design of Two-Speed Transmission for Electric Vehicles

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3736
Author(s):  
Jae-Oh Han ◽  
Won-Hyeong Jeong ◽  
Jong-Seok Lee ◽  
Se-Hoon Oh
Keyword(s):  
Electric Vehicle ◽  
Electric Vehicles ◽  
Automobile Industry ◽  
Bending Strength ◽  
Gear Tooth ◽  
Planetary Gear ◽  
Maximum Speed ◽  
Compact Structure ◽  
Simple Method ◽  
Paris Climate Agreement

As environmental regulations have been strengthened worldwide since the Paris Climate Agreement, the automobile industry is shifting its production paradigm to focus on eco-friendly vehicles such as electric vehicles and hydrogen-battery vehicles. Governments are banning fossil fuel vehicles by law and expanding the introduction of green vehicles. The energy efficiency of electric vehicles that use a limited power source called batteries depends on the driving environment. Applying a two-speed transmission to an electric vehicle can optimize average speed and performance efficiency at low speeds, and achieve maximum speed with minimal torque at high speeds. In this study, a two-speed transmission for an electric vehicle has been developed, to be used in a compact electric vehicle. This utilizes a planetary gear of a total of three pairs, made of a single module which was intended to enable two-speed. The ring gear was removed, and the carrier was used in common. When shifting, the energy used for the speed change is small, due to the use of the simple method of fixing the sun gear of each stage. Each gear was designed by calculating bending strength and surface durability, using JGMA standards, to secure stability. The safety factor of the gears used in the transmission is as follows: all gears have been verified for safety with a bending strength of 1.2 or higher and a surface pressure strength of 1.1 or higher. The design validity of the transmission was verified by calculating the gear meshing ratio and the reference efficiency of the gear. The transmission to be developed through the research results of this paper has a simple and compact structure optimized for electric vehicles, and has reduced shift shock. In addition, energy can be used more efficiently, which will help improve fuel economy and increase drive range.

Analytical Solution for Rotational Rub-Impact Plate Under Thermal Shock

2016 ◽  
Vol 32 (3) ◽  
pp. 297-311
Author(s):  
T.-Y. Zhao ◽  
H.-Q. Yuan ◽  
B.-B. Li ◽  
Z.-J. Li ◽  
L.-M. Liu
Keyword(s):  
Thermal Shock ◽  
High Frequency ◽  
Equations Of Motion ◽  
Low Frequency ◽  
Cantilever Plate ◽  
Analysis Method ◽  
Multiple Frequency ◽  
Width Direction ◽  
Blade Tip ◽  
High Frequency Vibrations

AbstractThe analysis method is developed to obtain dynamic characteristics of the rotating cantilever plate with thermal shock and tip-rub. Based on the variational principle, equations of motion are derived considering the differences between rubbing forces in the width direction of the plate. The transverse deformation is decomposed into quasi-static deformation of the cantilever plate with thermal shock and dynamic deformation of the rubbing plate under thermal shock. Then deformations are obtained through the calculation of modal characteristics of rotating cantilever plate and temperature distribution function. Special attention is paid to the influence of tip-rub and thermal shock on the plate. The results show that tip-rub has the characteristics of multiple frequency vibrations, and high frequency vibrations are significant. On the contrary, thermal shock shows the low frequency vibrations. The thermal shock makes the rubbing plate gradually change into low frequency vibrations. Because rub-induced vibrations are more complicated than those caused by thermal shock, tip-rub is easier to result in the destruction of the blade. The increasing friction coefficient intensifies vibrations of the rubbing plate. Minimizing friction coefficients can be an effective way to reduce rub-induced damage through reducing the surface roughness between the blade tip and the inner surface of the casing.

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