Model Of Gear Transmission System Research Articles

Simulation Analysis of Tooth Break Faults of Gear Transmission System based on Electromagnetic Torque Signal

The traditional gear fault simulation model focuses on the vibration signal. However, the vibration sensor is not easy to install, and the vibration signal is easily affected by the installation location and environment of the vibration sensor. The motor itself has the characteristic of sensor. But in the traditional integrated model of motor and gear, the gear model is established based on the dynamical equation of the gear. However, the gear transmission established by the dynamics of the gear can’t fully reflect the running state of the gear. Moreover, the more complex the gear transmission system, the more complex and inaccurate the dynamical equation will be. Based on the above situation, in this paper, the virtual prototype model of the two-stage gear transmission system with broken tooth fault in different parts of the gear is established in Adams, which is imported into Matlab and co-simulated with the motor control model built in Matlab. Then the electromagnetic torque signal is analyzed. The results show that different characteristic frequencies of gear faults can be detected in the electromagnetic torque signal. The virtual prototype model of gear transmission system can accurately reflect the motion state of gear, and the fault of the complex gear transmission system can be simulated.

Dynamics research on gear transmission system of oscillating float wave energy generator

Aiming at the problem of dynamic characteristics and dynamic reliability of gear transmission system in point wave acquisition system, combined with the characteristics of randomness and instability of waves, the dynamic model of gear transmission system is established based on the simulation of actual wave excitation, and the dynamic response of gear transmission system is solved. Using rain flow counting method, the time history of gear contact stress is statistically analyzed, and the contact stress spectrum and probability distribution function of each gear pair are obtained. Based on the random process function of the stress-strength interference model, the Monte Carlo method is used to calculate and analyze the change law of the reliability of the gear transmission system over time. The results show that the reliability of the gear transmission system gradually decreases with the increase of time within 20 years, and finally the reliability is 0.8. Speed increasing gear has the greatest impact on the reliability of the transmission system.

Nonlinear dynamic model of gear transmission system under the influence of vibration and noise

Nonlinear dynamic model of gear transmission system under the influence of vibration and noise

Vibration and Stress Response of High-Speed Train Gearboxes under Different Excitations

The vibration data of the gearbox on a high-speed train was measured, and the vibration characteristics were analyzed in this paper. The dynamic stress of the gearbox under the internal and external excitation was examined by a railway vehicle dynamic model with a flexible gearbox and a flexible wheelset. The ideal 20th polygonal wear was considered, and dynamic stresses of the gearbox under different polygonal wear amplitudes were calculated. The gear transmission model was established to study the dynamic stress of the gearbox under the influence of the time-varying stiffness of the gear meshing. Based on the rigid–flexible coupling model, and considering the influence of wheel polygonization, gear meshing time-varying stiffness, and wheelset elastic deformation, the dynamic stress of the gearbox was investigated with consideration of the measured polygonal wear and measured rail excitation. The results show that the dynamic stress of the gearbox is dominated by the wheel polygonization. Moreover, not only the wheel polygonization excites the resonance of the gearbox, but also the flexible deformation of the wheelset leads to the deformation of the gearbox, which also increases the dynamic stress of the gearbox. Within the resonant bandwidth of the frequency, the amplitude of the dynamic stresses in the gearbox will increase considerably compared with the normal case.

Scaling law of gear transmission system obtained from dynamic equation and finite element method

When the size of the gearbox is too large, the test will be difficult to carry out. It is an effective method to replace prototype with scale model. The original contribution of the paper is that the dynamic similarity theory is introduced into gear transmission system, and a method to predict the dynamic characteristics of gear system is proposed. The scale model of gear transmission system is designed by using dynamic equation and similarity theory, and the scaling law of dynamic response is obtained. By unifying the units of vector, the problem that the similarity ratio of the matrix in the dynamic equation can not be obtained is solved. Taking the parallel shaft gear transmission system as an example, the dynamic responses of different scale models and full size models are calculated by the node finite element method. The validity of scaling law is verified by the free vibration response and forced vibration response of the system. The numerical value and trend of the dynamic response of the full size model at different speeds can be obtained from the scale model.

Dynamic characteristics for coal shearer cutting unit gearbox housing

Long wall mining is most widely used in coal mining of China, and coal shearer is the most important machine due to its direct role in cutting coal. Nevertheless, coal mining enterprises are suffering from faults of coal shearer, especially cutting unit gearbox housing (CUGH). Published dynamic studies on CUGH have not considered the excitation caused by gear meshing and complete machine vibration. Due to the apparent lack of experimental validation of these published papers, the dynamic response of CUGH is not convincing. In this study, dynamic behavior of CUGH is investigated both theoretically and experimentally for finding out failure mechanism and improving reliability. Complete machine vibration and gear meshing vibration are two excitation sources for CUGH, and vibration is transferred via articulated holes and bearing holes. Hence, complete machine dynamics model is established for obtaining force on articulated holes. Dynamics model of gear transmission system is established for obtaining force on bearing holes. Stochastic cutting forces model is established as external load of complete machine dynamics model. Dynamics response is calculated by finite element model established by ANSYS. A measurement system to capture three-dimensional vibratory motions under realistic working conditions of coal mines is implemented by National Energy Mining Equipment Laboratory of China. Direct comparisons between predicted and measured results are presented to demonstrate the accuracy of the proposed model in predicting three-dimensional vibrations of CUGH. Maximum deformation and stress positions of CUGH are determined, and the excitation sources are investigated.

Hierarchical Modeling and Dynamic Analysis of Hoist System in Electric Mining Shovel

The hoist system of electric mining shovel (EMS) always encounters excessive vibration in present work. However, the shortage of suitable dynamic model has been the bottleneck of reducing vibration. In order to analyze the vibration of the EMS hoist system, a coupled dynamic model is proposed using the hierarchical modeling method, which contains couplings of bolt, bear, coupling, rope, and gear mesh. The components were equivalent to mass elements with several nodes corresponding to their structure. Considered helical gears and motors, a dynamic gear transmission model with couplings of bending, torsion, and axes was developed. Based on the dynamic model, the modal characteristics were calculated, and the vibration modes were classified to five types. Under the ripple drive torque simulated by Simulink, the dynamic characteristics of the hoist system in time domain and frequency domain were obtained using numerical integration with the Runge–Kutta method in Matlab. At last, the model validity was verified by contrasting the responses under actual test and the model. The dynamic model and study results can provide support for dynamic characteristic evaluation and dynamic optimization of the EMS hoist system.

Effects of macro-parameters on vibration and radiation noise for high speed wheel gear transmission in electric vehicles

Considering flexible shafts, a coupled dynamic model for the gear transmission system of wheel reducer used in electric vehicle was developed. By combining the acoustics finite element modal for housing in Virtual Lab and the coupled dynamic model for gear transmission system, a simulation method was proposed for the prediction of the radiation noise for the wheel reducer. Then, the effects of different macro geometry gear parameters including pressure angle and helical angle on the dynamic response and radiation noise were investigated under the rated working condition. Results show that the peak-peak value of the transmission error dramatically falls in the starting zone, followed by an upward trend with the increase of the pressure angle for the low speed stage gear pair. The minimum transmission error and vibration acceleration occur when the pressure angle is 17°. The increase of the pressure angle does not affect the sound pressure level at the field point obviously. The design case with 17° pressure angle shows the optimum radiation noise level, which is 4.41dB less than the original model. Compared to the pressure angle, the helix angle has a major influence on the transmission error, vibration acceleration and acoustic radiation noise. With the increase of the helix angle, the time-varying transmission error curve becomes more smooth with a lower peak-peak value. Besides, the increase of helix angle results in lowering the varying and fluctuating trend of both vibration acceleration and acoustic radiation noise. The design case with 24° helix angle shows the prime radiation noise level, which is 7 dB less than the original scheme.

Study on dynamic characteristics of spur gear transmission system based on different calculation models of time-varying mesh stiffness

Three kinds of gear mesh stiffness calculation models are developed for spur gear transmission system in this paper, namely, the dynamic model of gear transmission system based on the analytical mesh stiffness calculation by “slice method”, the gear transmission system dynamic model based on SIMPACK 225 force element, and the finite element dynamic model of gear transmission system. Based on these dynamic models, the mesh force and dynamic transmission error for the high speed and the low speed operation conditions are analyzed, respectively. The research results indicate that the results obtained by the three dynamic models are in good agreement with each other for both low and high speed operation conditions. The dynamic transmission error calculated by gear transmission system dynamic model based on mesh stiffness calculation with “slice method” are much closer to the results obtained by the finite element dynamic model. Consequently, considering the computation accuracy and computation time, the gear transmission system dynamic model based on the mesh stiffness calculated by “slice method” could be better applied to analyze the dynamic performance of gear transmission system considering the trade off between the computational accuracy and the efficiency.

Volume models for different structures of spur gear

The volume of gear transmission system has been concerned by people. At present, the researchers mainly focus on the optimization algorithm, but there is a lack of research on the volume model of gear transmission system. In the paper, the single-stage spur-gear transmission system is considered and the volume models for different structures of spur gear are built. Firstly, the influence of bottom clearance and the modification coefficient on the spur-gear volume are analysed. The formula of clearance volume is derived. Secondly, volume models of different structure of spur gear are built. In order to illustrate the accuracy of the models, the corresponding three-dimensional models of different structure of spur gear are established. Finally, the design parameters of spur gear are as the optimisation variables, the spur-gears design and transmission requirements are as the constraint conditions, the total minimum volume of single-stage spur-gear transmission system is as the optimisation target, the genetic algorithm (GA) toolbox in Matlab software is adopted in the optimisation. A single-stage spur-gear system is as an example, and the optimisation for minimum volume of single-stage spur-gear transmission is carried out.

Vibration analysis of shearer cutting system using mechanical hydraulic collaboration simulation

The cutting unit of a mining shearer is composed of a drum, gear transmission and hydraulic height adjusting mechanism. To obtain the dynamic characteristics of crucial components in the coal cutting process, a model of a drum cutting coal was constructed using LS-DYNA. The model of gear transmission was constructed with Adams, and a model of the hydraulic height adjusting system was constructed with AMESim. Data transmission and co-simulation of these three models were implemented with MATLAB. Changes of the meshing force, acceleration and amplitude–frequency characteristics of key gears under different conditions were obtained. From the research, we conclude that it is effective and feasible to apply the multi-software co-simulation used by this paper to research a complex mechanical–hydraulic system such as a shearer cutting unit; supports from a hydraulic cylinder can decrease the meshing force of gears to some extent; and the meshing force of gears increases significantly as the mining height of the drum increases.

Vibration performance discrete optimization of a gear system featuring confluence transmission used in marine gearbox

A dynamic model of gear transmission system which includes time-varying meshing stiffness, meshing damp and transmission error is established. Next, the analytical solution of the vibration response would be obtained by solving the dynamic model based on the harmonic balance method. And on this basis, a dynamic performance discrete optimization model of transmission sub-system would be constructed, which sets objective function up from vibration acceleration and the total mass of transmission sub-system, treats the module, number of teeth and helix angle as design variables, and takes gear strength and assembly relationship as constraints. Last, the optimal solution of design variables could be obtained through the multivariable mixed discrete optimization program which based on the branch-bound algorithm. The results show that the vibration acceleration and the total mass of transmission sub-system reduce by 34.6% and 6.8%, respectively.

Dynamic Efficiency of a Container Crane’s Hoisting Transmission System under Hoisting Dynamic Load

The dynamic efficiency of hoisting transmission system on a container crane is fundamental for accurate efficiency prediction, while the dynamic efficiency of hoisting transmission system has not been investigated sufficiently. This paper will focus on dynamic efficiency of hoisting transmission system under hoisting dynamic load. A power loss model of gearbox was built. Then the dynamic model of gear transmission was developed including time-varying mesh stiffness and hoisting dynamic load was studied. Power loss, dynamic efficiency, and equivalent static efficiency were conducted in hoisting and lowering working conditions. The result shows that dynamic efficiency which consists of the significant lower frequency component coincided with hoisting load torque of the higher frequency component which is directly related to dynamic mesh and bearing force. And in two processes, the equivalent static efficiency in constant speed stage is min, whereas maximum value occurs in different stage. The research results lay a foundation for hoisting gear transmission dynamic efficiency analysis.

Mathematical and Finite Element Modeling of Micro-Modification for Marine Gear

Based on the computer simulation technique, this paper used the professional gear design software MASTA and finite element software ANSYS combined with the method of gear micro-modification to redesign the gear profile and eventually realized the optimization design of gear micro-modification. Then the gear transmission model of one-level reducer was established to simulate and analyze the contact equivalent stress, transmission error, and meshing impact before and after gear modification. By comparing the simulations results it is found that gear micro-modification can lower meshing impact load, reduce the vibration strength, make gear transmission steady, and improve the gear bearing capacity. By comparing the transmission error curves and meshing impact load curves before and after gear micro-modification, this helps to understand the effects of gear micro-modification on the gear transmission and provides basis references for the future redesign of the marine gears with high strength and long service life.

Dynamic Reliability Analysis of Gear Transmission System of Wind Turbine in Consideration of Randomness of Loadings and Parameters

A dynamic model of gear transmission system of wind turbine is built with consideration of randomness of loads and parameters. The dynamic response of the system is obtained using the theory of random sampling and the Runge-Kutta method. According to rain flow counting principle, the dynamic meshing forces are converted into a series of luffing fatigue load spectra. The amplitude and frequency of the equivalent stress are obtained using equivalent method of Geber quadratic curve. Moreover, the dynamic reliability model of components and system is built according to the theory of probability of cumulative fatigue damage. The system reliability with the random variation of parameters is calculated and the influence of random parameters on dynamic reliability of components is analyzed. In the end, the results of the proposed method are compared with that of Monte Carlo method. This paper can be instrumental in the design of wind turbine gear transmission system with more advantageous dynamic reliability.

The Research on Modeling and Dynamic Simulation of Gear Box Virtual Prototype Based on Pro/E and ADAMS

In this paper, the combination of Pro\/E and ADAMS to build a virtual prototype model of gear transmission, the dynamic simulation of the gear meshing process, study on dynamic speed, mesh force bearing load, where, for the gear box of the engineering analysis and optimization design. A 3D modeling and designing software, established a parametric model of a gear box of the rack and pinion drive mechanism, which is used in large gantry milling machine XK2425-600. The data interface module MECHANISM/Pro is used to convert the Pro/E model data to ADAMS, and then the virtual prototype is built in it. The rotational speeds, meshing forces, and reactive loads at bearings are obtained by dynamic simulation of the virtual prototype, which can be used in finite element analysis as boundary condition, helped to calculate the strength and stiffness of the box.

Vibration Analysis of Gear Transmission System in Electric Vehicle

This paper presents a systematic research on the gear transmission system of the electric vehicle. An accurate 3-D model of the gear transmission system is established in UG (Unigraphics NX) using software Gearwizard, and then imported to ADAMS/View environment. Based on the contact force of ADAMS, the vibration at 3 different test points of the model are simulated. The simulation results seem to be in good accordance with the test results, which proved the validity of the gear transmission model. Finally, the influence of helix angle on vibration at 3 different test points are also researched. The results of the total analysis can be used further to optimize the gear transmission system of the electric vehicle.

Dynamics Model of Gear Transmission with Combined Friction and Clearance by Using Bond Graph Method

Aiming at the problem of nonlinear dynamics of gear transmission system with clearance and friction,a bond graph model of the gear transmission system with clearance and friction is build based on the nonlinear features of tooth surface friction,time-varying gear mesh stiffness and gear clearance,in which modulated resistive element is used to describe the parameters of tooth surface friction characteristics and two modulated transformers are uded to present driving friction arm and driven friction arm respectively.Accordingly,the deformation of gear along the meshing line is divided into three statuses as gear clearance is the nonlinear function of piecewise-linear,thus the concept of switched power junctions is introduced to describe time-varying gear mesh stiffness with clearance that uses clearance as the signal,and flow source element(Sf) to represent the influences of the gear transmission error on the system.A spur gear pair is taken as an example,advanced software 20-sim is used to simulate the model.The results are compared with those from Matlab to check the bond graph model and verity its credibility.

A Nonlinear Dynamics Bond Graph Model of Gear Transmission

A nonlinear dynamics bond graph model of gear pair is established including the time-varying stiffness, transmission error and tooth surface friction. A capacitive component C is introduced to represent the loads and tooth elastic deformation while introducing the concept of switched power junctions (SPJ) to describe time-varying gear mesh stiffness with clearance, and flow Sf represents the influences of the gear transmission error on the system dynamic equations. The tooth surface friction bond graph model involving the relationship of the relative velocity and the direction of friction are developed. According to the causal relations and the power flow, the state-space equations of the gear bond graph model are obtained. Research results show that bond graph modeling method can solve the modeling problem of the gear nonlinear dynamics.

A Model of Gear Transmission: Fractional Order System Dynamics

A theoretical model of multistep gear transmission dynamics is presented. This model is based on the assumption that the connection between the teeth of the gears is with properties within the range from ideal clasic to viscoelastic so that a new model of connection between the teeth was expressed by means of derivative of fractional order. For this model a two-step gear transmision with three degrees of freedom of motion has been used. The obtained solutions are in the analytic form of the expansion according to time. As boundary cases this model gives results for the case of ideally elastic connection of the gear teeth and for the case of viscoelastic connection of the gear teeth, as well. Eigen fractional modes are obtained and a vizualization is done.