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1
Wang, Zhongwei. "Dynamic modelling of planetary gear systems for gear tooth fault." Thesis, Curtin University, 2010. http://hdl.handle.net/20.500.11937/1284.
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Geared systems have been widely used in mechanical applications for more than a hundred years. A large range of literature has been published especially for spur/helical gear systems and the investigations into technical areas of spur/helical gears have been very well developed, including understanding of condition monitoring systems, diagnostic and prognostic methods. However, there is a lack of understanding on the general dynamic behavior of planetary gear systems with tooth faults. Planetary gears are normally used as effective power transmission elements with high power to weight/volume ratios, large speed reductions in compact volume, and high reliability. They tend to have high efficiency and are used in many applications, such as automotive, heavy truck/tractor, helicopter, wind turbines and bucket wheel reclaimer gearboxes.The purpose of this research is to develop a vibration analysis system that simulates dynamic behavior of large low speed, high torque planetary spur gear systems such as used in bucket wheel reclaimer and wind turbine gearboxes, with and without gear element faults. This thesis investigates lumped mass modelling methods for planetary gearbox dynamic behavior based on previous gearbox modelling research including the use of the coupled torsional-transverse behavior of the gear body. The dynamic model of the planetary spur gear system includes effects such as: variable tooth mesh stiffness, dynamic transmission error effects, and pitch and profile excitation for gear fault detection purposes. Different tooth faults are simulated using the concept of combined torsional mesh stiffness. The dynamics of spur planetary gear systems with and without tooth faults are compared and analyzed to improve the understanding of fault detection in the present gear systems.Dynamic modelling of gear systems, such as outlined in this thesis can assist in understanding the consequence of large transient events, including the fluctuations in tooth loads which can reduce gear fatigue life and lead to further tooth damage. Early detection of faults on gear teeth can be used to initiate maintenance actions in order to reduce repair work and avoid catastrophic breakdown.
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Xue, Song. "An investigation of gear meshing behaviour of planetary gear systems for improved fault diagnosis." Thesis, Curtin University, 2016. http://hdl.handle.net/20.500.11937/141.
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This research has presented gear dynamic models and associated simulations to improve gear fault detection. These models include the use of finite element and lumped parameter methods for both fixed axis and planetary gear systems. The findings in this research provide an improved understanding of the gear fault mechanism and advance the gear fault detection capability of the whole drive train system. It also suggests further effective ways of monitoring the whole gear train system.
3
Ding, Huali. "Dynamic wear models for gear systems." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1194025602.
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Sommer, Andrew Patrick. "VIBRATION-BASED HEALTH MONITORING OF MULTIPLE-STAGE GEAR TRAIN AND DIFFERENTIAL PLANETARY TRANSMISSION INVOLVING TEETH DAMAGE AND BACKLASH NONLINEARITY." DigitalCommons@CalPoly, 2011. https://digitalcommons.calpoly.edu/theses/631.
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The objective of this thesis is to develop vibration-based fault detection strategies for on-line condition monitoring of gear transmission systems. The study divides the thesis into three sections. First of all, the local stresses created by a root fatigue crack on a pinion spur gear are analyzed using a quasi-static finite element model and non-linear contact mechanics simulation. Backlash between gear teeth which is essential to provide better lubrication on tooth surfaces and to eliminate interference is included as a defect and a necessary part of transmission design. The second section is dedicated to fixed axis power trains. Torsional vibration is shown to cause teeth separation and double-sided impacts in unloaded and lightly loaded gearing drives. The transient and steady-state dynamic loading on teeth within a two stage crank-slider mechanism arising from backlash and geometric manufacturing errors is investigated by utilizing a non-linear multi-body dynamics software model. The multi-body model drastically reduces the computation time required by finite element methods to simulate realistic operation. The gears are considered rigid with elastic contact surfaces defined by a penalty based non-linear contact formulation. The third section examines a practical differential planetary transmission which combines two inputs and one output. Planetary gears with only backlash errors are compared to those containing both backlash and tooth defects under different kinematic and loading conditions. Fast Fourier Transform (FFT) analysis shows the appearance of side band modulations and harmonics of the gear mesh frequency. A joint time-frequency analysis (JTFA) during start-up reveals the unique vibration patterns for fixed axis gear train and differential planetary gear, respectively, when the contact forces increase during acceleration.
5
Fang, Brian. "CAE Methods on Vibration-based Health Monitoring of Power Transmission Systems." DigitalCommons@CalPoly, 2013. https://digitalcommons.calpoly.edu/theses/1143.
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This thesis focuses on different methods to analyze power transmission systems with computer software to aid in detection of faulty or damaged systems. It is split into three sections. The first section involves utilizing finite element software to analyze gear stiffness and stresses. A quasi-static and dynamic analysis are done on two sets of fixed axis spur gears and a planetary gear system using ABAQUS to analyze the stress, strain and gear mesh stiffness variation. In the second section, the vibrational patterns produced by a simple bevel gear system are investigated by an experiment and by dynamic modeling in ADAMS. Using a Fast Fourier Transform (FFT) on the dynamic contact forces, a comprehensive frequency-domain analysis will reveal unique vibration spectra at distinct frequencies around the gear mesh frequencies, their super- and sub- harmonics, and their side-band modulations. ADAMS simulation results are then compared with the experimental results. Constraints, bearing resistant torques, and other key parameters are applied as closely as possible to real operating conditions. The third section looks closely at the dynamic contact forces of a practical two-stage planetary gear. Using the same FFT approach in the second section, a frequency-domain analysis will reveal distinct frequencies around both the first-stage and the second-stage gear mesh frequencies, and their harmonics. In addition, joint time-frequency analysis (JTFA) will be applied to damaged and undamaged planetary gear systems with transient start-up conditions to observe how the frequency contents of the contact force evolve over time.
6
Ligata, Haris. "Impact of system-level factors on planetary gear set behavior." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1172599656.
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Linderstam, Albin. "Analytical tool for electromechanical actuators for primary and secondary flight control systems : Optimization of the initial design of the EMA using parametric sizing models." Thesis, Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-74246.
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The number of flights have increased by 80% between 1990 and 2014, and the demand for air travel continues to increase. Even though the aviation sector contributes to economical and social benefits, it still affects the climate change [1]. A first step to minimize the environmental impact is to develop more electric aircraft (MEA), where the idea is to maximize the use of electricity and improve the overall energy effciency [2]. In most of today's aircraft, large mechanical transmission shafts with a lot of components are driven by central power units, termed centralized drive systems. By the use of electromechanical actuators (EMAs), a distributed drive systems can be used instead, which increases functionality, reduces mass, maintenance and energy consumption, as well as improves manufacturing and assembly [3]. When designing electromechanical actuators, one must take into account a lot of parameters that affect each other in various ways. It is often a time-consuming job to find the most optimal choice of architecture. Parameters such as temperature, load, lifetime and effciency to mention a few. This master thesis offers a new analytical tool for EMAs of primary and secondary flight control systems for Saab Avionics Systems. The aim of the analytical tool is to characterize the parts of the system and identify important parameters in order to find the most optimal choice of architecture. The tool focus on the main mechanical components such as the three-phase synchronous permanent magnet motor, power-off brake, two-stage planetary gearbox and ball screw. The tool developed in this project generates an initial design of the EMA with optimized dimensions in order to minimize both mass and energy consumption. It functions by identifying three main groups of parameters: The input parameters: fixed values defined by the customer demands The design parameters: variables that the user can change to find the optimal choice of architecture The output parameters: resulting values of either performance or dimensions By defining few design parameters for each component, and implementing multidisciplinary design optimization (MDO), the analytical tool can find an optimized solution for each specific project in a time-efficient way. The final values of the parameters characterize the performance of the EMA.
8
Boguski, Brian C. "An Experimental Investigation of the System-Level Behavior of Planetary Gear Sets." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1291009879.
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Cooley, Christopher Gary. "High-Speed Dynamics and Vibration of Planetary Gears, Vibration of Spinning Cantilevered Beams, and An Efficient Computational Method for Gear Dynamics." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1354558979.
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Liang, Chun-Chieh, and 梁竣傑. "Dynamic Load Analysis of Planetary Gear Systems." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/53926229843237199791.
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碩士中華大學
機械與航太工程研究所
94
This thesis expects to analyze the dynamic characteristics of the 2K-H planetary gear systems that includes the investigation effect of the design parameter on the gear system dynamics. The analysis techniques of planetary gear system dynamics will be established. Due to their special features of the high power-volume ratio and easy realization of the concentric input and output shafts, the planetary gear sets have been widely used in machine transmissions. However with the increase of their higher demand of specs such as rotation speed, precision, and noise and vibration etc, the analysis of dynamics for the gear systems has become important. Firstly, the tooth profiles of standard and nonstandard gears, mesh points, and phasing relation of variant teeth pairs are formulated. Then, the time varying stiffness of sun gear- planet gear and ring gear- plant gear meshing gears can thus be calculated. Next, after employing Lagrange’s equation, the equations of motion of the gear systems in an equivalent discrete from, including the models of gears, a motor, gear shafts, and loadings, are derived. Further, the torques applied on the driving and driven shafts are the excitation force of the systems. Finally, using the Jacobi transformation and the Runge-Kutta integration respectively, natural frequencies, dynamic deformations and meshing forces, and dynamic factor will be calculated. Additionally, this thesis, using the commercialized software LS-DYNA, calculates the planetary gear system dynamics in a continuous approach. The analyzing process; including geometric model and mesh generation, initial and boundary conditions, and numerical and output controls; are introduced abundantly. The result by using LS-DYNA is compared to the result by the above discrete model by which the proposed discrete model both in theory and in numerical can be verified. Finally the influences of the design parameters including the rotation speed, damping, and correction factor on the gear system dynamics analysis are investigated. It demonstrates that the theoretic model and the calculated results of this thesis can be successfully applied when designing planetary gear systems.
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Chen, Song-Shyong, and 陳松雄. "Design and Development of a Planetary Gear Locomotive Systems." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/46762861079183493291.
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碩士國立臺灣科技大學
電機工程研究所
82
This main purpose for the development of walking machines is to replace wheel or tracked vehicles advancing on rugged road or areas which is inaccessible to either wheeled or tracked vehcles. This thesis aims at the research of a high performance plane- tary gear locomotive leg. In addition, various control algorithms shall be developed and applied to perform the "walk". In the developed hardware, we have designed a multiaxis cont- rol system for the leg. In addition, interface circuits are also included. As for the developed software, there are system testi- ng programs, trajectory planning program and the position and force control software. Experimental results shows that the developed leg''s performa- nce has met our expectation. This leg shall pave a way for furth- er development of a quadrupeed walking machine.
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Chen, Jian-Yu, and 陳建羽. "Investigations on Dynamic Characteristics of Spur and Helical Planetary Gear Systems." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/83935478526713870294.
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碩士中華大學
機械工程學系碩士班
96
This thesis investigates dynamic characteristics of spur and helical planetary gear systems using continuously geometric models of the finite element approach (FEM). Not through a CAD geometric process but directly using the derived involute tooth profile equations generated by a rack cutter, high quality element models of planetary gear systems are parametrically and automatically constructed. After assigning suitable analysis conditions, numerical modal and dynamic responses of the planetary gear systems are solved by the commercialized general purpose dynamic FEM software, LS-DYNA, through which system natural frequencies, modal shapes, and dynamic fillet stresses are calculated. Additionally, the harmonic resonance of fillet stresses arising from excitation of nonlinear meshing stiffness of tooth pairs is also discussed. Accordingly, the connection between system modal characteristics and dynamic fillet stresses can be found. Finally, sophisticate parametric studies are performed in order to reveal the effects of variant influential factors on the modal and dynamic characteristics of planetary gear systems. Effect of material properties and design factors on modal behaviors and dynamic responses are incorporated. In the aspect of modal analyses, influences of Young's modulus (stiffness) and density (inertia), carrier stiffness, supporting bearing stiffness, gear module, helical angle, distributing angles of planet gears, number and meshing position of engaging tooth pairs on the modal characteristics are investigated. Plentiful useful results of gear modal property are obtained through the study. In the dynamic aspect, influences of the ring gear addendum and backlash of meshing gears on the dynamic fillet stresses of planetary gear systems are also discussed. Potentially, the proposed continuum geometry FEM approach can be served in analyzing dynamic problems of wide categories of planetary gear systems. The obtained modal and dynamic results are quite referable in design of planetary gear systems.
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VincentSebastian and 高京正. "On the Innovative Design of Double Planetary Gear Transmission Systems for Hybrid Electric Vehicles." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/a22ny7.
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Chen, Dao-Hong, and 陳道鴻. "Study of Planetary Gear Power Split System." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/21738007840821932468.
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碩士明志科技大學
機械工程系機械與機電工程碩士班
103
This study designs and produces a power split drive (PSD) of the planetary gear set in order to verify the operation of parallel hybrid vehicles and its electromechanical energy conversion efficiency. Planetary gear contains a 30 teeth of the sun gear, three 24 teeth of planetary gear and a 78 teeth of ring gear. For the convenience to measure the energy conversion efficiency of the power split drive, this study uses the test rated power of 1000W BLDC to instead the engine, and the rated power of 750W BLDC and 350W BLDC to instead MG2 as motor and MG1 as generator respectively to test the operation of the power split drive (PSD) of the planetary gear set and measuring the energy power systems in normal mode and recirculation mode of conversion efficiency. These results indicate that the production of this study, a power split drive (PSD) of the planetary gear set, maximum system efficiency is 50% approximately. This study uses ADVISOR as a simulation platform to analyze each operation mode calculation of TOYOTA Prius. And power split drive is simulatedrespectivelyin the normal and re-circulation driving modes. The speed and torque of engine and MG1 and MG2 are inputs and the ring gear is output to measure the output torque, the speed and power variation ofpower split drive in two driving modes.
15
Wu, Yu-lung, and 吳昱龍. "Design of Planetary Gear System with Double Circular-Arc Hilical Gear." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/82683420792134468931.
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碩士正修科技大學
機電工程研究所
95
This paper studied and improved a three stage planetary gear winch with double circular-arc gears. Tooth contact analysis and bending stress were studied by chinese standard double circular-arc gear. The contact stress can be reduced largely because the relative curvature of tooth of double circular-arc gear is smaller than involute gear. The winch with double circular-arc gear can sustain a larger torque than the winch with other type of gear, therefore the size of the winch can be reduced too. Tooth contact stress and bending stress were studied in this paper. Finally, we developed a new tooth profile for double circular-arc gear. This paper improved original double circular-arc gear, developed a new design and applied analysis software to this drive. The processes of design and manufacture were more simple. The advantage of the new drive was confirmed.
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Chih-HsiangLiang and 梁智翔. "Design and Analysis of Small-Module Planetary Gear System." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/e6qck7.
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碩士國立成功大學
航空太空工程學系碩士在職專班
103
SUMMARY The objective of this research is to design and develop a small-module planetary gear system which is applied to medical dental low speed Handpiece. To design this planetary gear system, the MITCalc and Solidworks softwareare used, and through mechanical manufacturing methods to produce the hardware. Through measurements this planetary gear system is verified to be consistent with the requirement of ISO 14457. Also it is found the relationship between the parameters and performance. As the result of the experimental, upgrade the accuracy of gear can reduce the temperature rise, noise and vibration. Decreasing the gear backlash can reduce the noise, but the temperature rise will be high; Increasing the gear backlash can lower the temperature rise, but the noise will be raised also. Therefore, the gear backlash will affect the temperature and noise. With or without the profile shifting coefficient makes no big difference of the temperature; however, the noise and the vibration is obvious lower than that of the gear with profile shifting coefficient. Keywords: planetary gears, small-module gear, spectral response, vibration and noise. INTRODUCTION There are many gear design software, however, no one focus on the important gear parameter of its accuracy, backlash, profile shifting coefficient...etc. All of those parameters are dependent on designer’s experience to adjust, and it often requires a lot of time to make adjustments. This thesis will analyze and discuss the effects of the parameter to the temperature rise, noise, vibration data by experiment to find the relationship between these parameters, to reduce research and development time and to improve gear quality. METHODS AND MEASUREMENT In this study, MITCalc software is utilized as the design platform to calculate gear parameters and output 3D models. Solid models is also built by 3D CAD software – Solidworks. By mechanical manufacturing methods, a planetary gear system with module is 0.25 and reduction ratio is 1: 4 is produced with its model no. 2K-H. In experimental and analysis, install the planetary gear system onto a medical dental low speed handpiece which is commercially available. The measuring instruments including: digital thermometer to measure the temperature, programmable sound level meter to measure noise, and spectrum analyzer to measure the vibration data. RESULTS AND DISCUSSION As the result of the experimental work, accuracy class will be the most important parameters affecting the quality of the gear system. When the gear accuracy class upgrade from 4 to 2, it can reduce the temperature rise 4℃, reducing the noise 8 dBA, and reducing the vibration quantity 2 Grms. The performance of profile shifting coefficient of gear is better than that of no profile shifting coefficient of gear, reducing the noise 2 dBA, reducing the vibration quantity 0.75 Grms, but for temperature rise is no big difference. As the gear backlash from 0.01 ~ 0.02mm is enlarged to 0.02 ~ 0.03mm, lubricating effect becomes better, and temperature rise can be reduced 1.4 ℃, because the gear backlash increased; however, the noise increased to 2.8dBA and vibration quantity increased to 0.24 Grms. CONCLUSIONS The design software of MITcalc a planetary gear system is successfully used in the small-module gear system design with a satisfactory performance. It can be made conformable to the medical regulations requirements of ISO 14457. As one needs a high quality planetary gear system, it can be upgraded by raise the accuracy class. When one needs a low noise and low vibration planetary gear system, it can be set profile shifting coefficient and decrease backlash of gear. And as you need to reduce the temperature rise of the planetary gear, it can be appropriately enlarged gear backlash.
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Wei-CheHsu and 許維哲. "Analysis of Dynamic Characteristics of a Planetary Gear System." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/87024544299855666506.
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碩士國立成功大學
航空太空工程學系碩博士班
101
Dynamic characteristics of a heavily-loaded planetary gear speed increaser of a wind turbine is analyzed by using the finite element method in this thesis. All gears and carrier are considered to be rigid and rotating shafts are modeled as Timoshenko beams. The Lagrangian approach is used to derive the equations of motion of planetary gear system, and dynamic response is obtained by using the Runge-Kutta method. The effects of number of planetary gears on the lateral displacement of gears, pressure angle and contact ratio between the sun gear and the planetary, reaction force of bearings of the system are investigated. Numerical results of this research show that when the number of planetary gears increases, lateral displacements of gears and of the bearing at the output terminal decrease, and so do the amplitude of pressure angle and contact ratio. However, lateral displacements of the bearing at the input terminal increase as the number of planetary gears increases.
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Lin, Kai-Yi, and 林凱毅. "Analysis and Design of Planetary Gear for Vehicle Steering System." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/ybnnrw.
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碩士國立臺北科技大學
車輛工程系所
98
Most of steering systems use the rack and pinion to transform the rotation of motor into straight-line motion currently. The rack and pinion have good performance in mechanical efficiency, but the overall size will increase when the motor and gear box are used .Not only the manufacturing cost raise ,but the spatial arrangement becomes complicated. Therefore, this study plans to substitute the lower cost and smaller size of the planetary gear set for the existing mechanism to meet the required straight-line motion. In this research, the new straight-line motion mechanism use a basic five planetary gear set with the ring gear fixed and sun gear input. In this study, the three-DOF gear steering mechanism is based on the basic planetary gear straight line , the mechanism refer steering angle and speed to adjust the motors to achieve the appropriate steering condition.
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Chang, Chia-Chen, and 張家禎. "A Design of the Planetary Gear Mechanism for Non-Independent Suspension System." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/ef9u8j.
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碩士國立臺北科技大學
車輛工程系所
101
Most current Non-Independent suspensions use simple 4-bar linkages by linking them to bodies to achieve the resistance of rolling. However, some of these mechanisms occupy a large quantity of space, which reduce the passenger space, and even increase the weight of entire vehicle. This study proposes several types of planetary gear mechanism to substitute the original 4-bar linkage, by using the features of straight track on specific condition, in addition to minimize the size of mechanism, then develop a novel Non-Independent suspension. According to body roll angle versus roll stiffness and body center gravity translation, this study selects the best mechanism design way which has good performance on roll stiffness, center gravity location and size. The purpose is to let passengers tilt less during cornering, and maintains the axle being horizontal to the road, which made more tire contact to the road to ensure the safety and stability of driving.
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Tsai, chia-jen, and 蔡嘉仁. "Mode Analysis of Planetary Gear System by Using a Finite Element Approach." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/g4qj8c.
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碩士中華大學
機械工程學系碩士在職專班
101
Large wind turbines can reduce carbon dioxide and have been the most potential renewal alternative to fossil energies. The tendency is to enhance power efficiency and reduce the cost. The current issue is how to improved benefit of electricity generation and cost down for wind turbine. According to the aspect of cost, volume, reliability and so on, single stage and multi stage gear box play an important role on large scale wind turbine. This analysis of this study uses the finite element software of LS-DYNA discussion modal analysis of planetary gear system. Especially main point is focused both on single stage and multi stage planetary gear system, analysis of natural frequency and mode response. Also, it is includes that investigation on the influences of supporting bearing stiffness and carrier stiffness on gearing modal properties of planetary gear systems, and analyzing the effect of large scale wind turbines which can be the key issues of the larger wind turbines in the future. This research key point are supporting bearing stiffness and carrier stiffness on gearing modal properties effect of the mode of planetary gear systems. In addition, I also study the modal characteristics of a double-stage system. When change materials and rigid module, the effect of natural frequency and mode relationship for double-stage system is discussed. By comparing of stiffness variation and natural frequency, relation of different materials on sun gear, ring gear and planetary gear is attained. It is also expected that the obtained results in this study can facilitate the design of the large-scale planetary gear systems.
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Wu, Bing-Siou, and 吳秉修. "Design and Analysis of Planetary Gear System by CAD and CAE Technology." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/32576394547768096167.
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碩士正修科技大學
機電工程研究所
96
With the development of computer science and manufacturing technique, CAD and parametric technique are used in mechanical field. The development of production parametric CAD system has become certain trend in information and digital enterprise production. At present, although in volute planet gear reducer are applied extensively in mechanism, the complex structure of the system brings great difficulty to designer. Therefore , an in volute plant gear reducer three demonism parametric CAD system of based on AMD will be discussed in this thesis , and can design all parts of the reducer conveniently on visual circumstance . This system not only should improve the design efficiency, but also should be valuable to the user. This plan with focus a software development about planet reducer Firstly, the CAGD of spur gear using VBA wall be study, which com solved the problem of twitch profile drawing in AMD. Then, the FEM package will be use to solve several important problem in simulation, and the result will be analyze the various parameters of gear forging process. There are several important factors such as the friction factor which has great influence on the radial flow of the material will be investigated. Finally the DEFORM-3D package will be solved the slightly Defoe of the die. Additionally, lot of simulations will be done to analyst, the different factors influencing the gear tooth accuracy, such as the elastic expansion of die and the spring-back of the forged gear consequently the deformation mechanism of the closed die will be obtained and a new method of tooth profile modification will put forward.
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Wu, Ji-Shuo, and 吳基碩. "Dynamic Response Analyses of Planetary Gear System Including Stiffness and Inertia Effect." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/51580286082390640972.
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碩士中華大學
機械工程學系碩士班
103
Gear transmission has been widely used for fine operation performance of smooth running, high efficiency and high load to weight. With increasing quantity of large scale wind turbines become the most potential source of renewal energies. However, reliability increase in the harsh operation condition and performance enhancement of their geared transmission trains is the most critical topic. Recently, nonlinear dynamic effect due to the weight has been highly concerned. Thus in this study dynamic analyses are undertaken to a single-stage helical planetary gear system using a 3D discrete stiffness model. The bearing stiffness, weight, and inertia of wind rotor and generator are also incorporated. Accordingly, the dynamic responses of the planetary system are resulted after assigning at constant speed and input load operation. The dynamic contact forces between gear pairs and gear-bearing pairs are calculated, the dynamic contact force of planet gearing are discussed at kinds of weight, inertia, and bearing stiffness. Planetary helical speed increasing gearings used in large scaled wind turbines are complex and multi-degrees of freedom dynamic systems. This study focuses on modal characteristics of single stage planetary gear systems and their dynamic characteristics under variant wind types of extreme fluctuation excitations. The harmonic vibration due to non-linear mesh stiffness of gear pairs is also investigated. Both approaches which respectively use an equivalent discrete model and finite element model to calculate dynamic responses and modal characteristics are used. In the discrete approach, the equivalent time varying mesh stiffness and meshing phases among the external and internal gear pairs will be derived. The geometry and assembly constraints of the planetary gear sets are also established. Then, equations of dynamic analyses for single stage planetary helical gearings are derived. Additionally, stiffnesses of ball bearing and shafts are also incorporated. The excitations exerting on gearing input and output shafts are applied. After performing numerical calculations, the dynamic responses of gearings are obtained. Natural frequencies and modal shapes are also resulted using the modal analysis. The FE results are compared with the numerical results of the discrete model. Basing on the variant operation conditions, the dynamic contact forces between gear pairs and gear-bearing pairs are calculated, the dynamic contact force of planet gearing are discussed at kinds of weight, inertia, and bearing stiffness, The result shows weight, inertia, and bearing stiffness are extremely important for investigation for gear dynamic behavior.
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You, Tian-Fu, and 游添福. "The Study on Improving Shift Quality of Transaxles of Planetary Gear System." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/hbwmbd.
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碩士國立臺北科技大學
車輛工程系所
94
The front engine front drive (FF) vehicles with automatic transaxles were produced before 2004, their shift control mechanism of transaxles of planetary gear system, such as hydraulic/electronic control unit or components of clutch didn’t have well shift control. So it caused unusual vibration in the shift process when vehicles start moving or driving. The vehicles with automatic transaxles used the oil pressure to release or compress the band assy-trans. and components of clutch to control the planetary gear system in order to achieve the shift task. When vehicles shift during start moving or driving, the oil pressure influence on the components of clutch will produce the vibration and noise which were caused by the torque change and the slip of speed ratio. These vibration phenomenon in the long time use will cause the clutch house or the connect place between clutch house and the clutch shaft broken. Moreover will reduce the life-time of transaxles or engine supporter and affect the drivers’ or the passengers’ comfort. This study improved the backing plate in the clutch of transaxles, during long time and long distance testing bench and road testing. The results show that the improved transaxles can reduce the vibrations and noise when the clutch operating. It can efficiently solve the problems which occur in clutch house and the connect place between clutch and clutch shaft. Then it also increase the life time of transaxles and promote the comfort of the car driving.
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LU, PO CHING, and 呂柏慶. "Dynamic Analyses of Single-Stage Planetary Gear System in Large Scaled Wind Turbines." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/67812239693414676412.
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碩士中華大學
機械工程學系
103
MW wind turbine is the most promising changes in various green energy program, but the growth rate of planetary gear set of wind turbines use wind field height changes due to the grid for security reasons, needs to consider starting, running, shutdown, emergency brake, etc. shock loading effects, master up gearbox to withstand intense changes load temporarily / steady-state response of the lower gear, the safety not only important for the reliable operation of wind turbines, the vibration noise reduction and long-term monitoring of the operation of technological development is also a key technology, especially towards a more the development trend of large offshore units, its performance and stability of the gear box is an important key. This study established a three-dimensional helical wind turbine planetary gear set of discrete mode calculation and dynamic contact force between the bearing, via setting various initial conditions and operating conditions in order to analyze the load and speed of the wind turbine startup and operation of gear change dynamic characteristics of the process of driveline extensive discussion, and ladder diagram shows the various operating conditions of the analysis conditions setting. The use of gear planetary gear set of dynamic contact force and experimental results verified by NREL. And finally discuss the impact of the various gear initial conditions and operating conditions of the planetary gear set of dynamic contact force, and obtained important results: Initial conditions for the static value, impact load torque and acceleration effects hardly affect the dynamic response of the gear. Mode and amplitude of the rotation speed increases hardly affects the contact force, the cycle of the sine wave is changed. The influence of gravity can be regarded as a sine wave approximation static but change in load force, but it causes the engagement corresponding to the respective planetary gear dynamics of phase. A sudden increase of the rated torque significant dynamic effect and produced a large amplitude, the effects of gravity will cause the dynamic response corresponding to the engagement between different planetary pairs of phase and produce a large inertial force applied to the planetary gear set.
25
Liu, Kun-Nan, and 劉坤南. "An Experimental study on identification of planetary gear train system by Using Genetic Algorithms." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/33789138060958665266.
Full textAbstract:
碩士國立中山大學
機械工程學系研究所
89
Abstract In this thesis, a simple dynamic model of the planetary gear train system is developed. Because of the dynamic equations deriving from designing a planetary gear train system are complex and nonlinear, and the controller design is difficult. If we take the planetary gear train system as a pure speed-down mechanism, and then the accuracy of the planetary gear train system will lose. So, we develop the dynamic equations of the planetary gear train system concerning with the conception of friction losses. Furthermore, the MGA method is used to identify the parameters of this system. The modified genetic algorithm (MGA) is proposed from the simple genetic algorithm (SGA) with some additional strategies, such as Elitist and Extinction strategies. From the computer simulations and the experimented results, it is concluded that the parameters of this system searched by using MGA will be more precise than the parameters searched by using LMS.
26
Yang, Chin-Cheng, and 楊金晟. "Study of Planetary Gears type-Continuously Variable Transmission System for Vehicle." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/yytdx3.
Full textAbstract:
碩士國立臺北科技大學
車輛工程系所
96
The Continuously Variable Transmission system is always the vehicles research and development goal, many vehicle manufactories unceasing to improve and invest new design to save energy, reduce environmental pollution and promotion comfortableness. The currently applied the broadest Continuously Variable Transmission system was still by the belt type or steel-belt type, but it’s unable to use in larger power vehicles. In this study, by using gear meshing has the high efficiency characteristic, so selects the planetary gear, and two degrees of freedom characteristics achieves using its organization in Continuously Variable Transmission. The conception uses the double power supply to actuate, one is the main power supply, another power is DC motor, and in order to achieve continuously variable speed by controls DC motor rotational speed. The study provides six connection methods, and aims at one kind of connection method detailed discussion. The result shows the Planetary Gear Continuously Variable Transmission system with compact structure does not to waste too much spare. Because of using the gear meshing transmission, so it has better transmission efficiency than the common vehicle with the Continuously Variable Transmission system.
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Chen, Chi-Kuo, and 陳齊國. "A Novel Design of the Planetary Gear Mechanism for Electric Parking Brake and Steering System." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/6y2xtp.
Full textAbstract:
碩士國立臺北科技大學
車輛工程系所
100
Most current electric parking brake systems use thread and worm gear sets or self-locking screws to transfer the rotational motion of the electric motor into the linear motion, required by a braking actuator and to maintain braking effort, because of the system’s irreversible nature, i.e. the friction angle between the contact surfaces is larger than the lead angle of the worm or the screw; however, worm gear sets and self-locking screws have low transmission efficiency, resulting from the friction force, which consumes more power from the motor. This study proposes a novel parking brake mechanism, which uses a special planetary gear train without a sun gear to improve upon the performance of existing electric parking brake systems. The dimensions of the gear sets are determined through a systematic design process. Kinematic and force analysis demonstrate that an approximately square locus, generated from a specific point on the planet gear, allows transfer of motion and a level of self-locking. Furthermore, in this research, the new straight-line motion mechanism, based on the basic planetary gear mentioned in the last design of electric parking brake, refers to the steering wheel angle to achieve variable-gear ratio in different condition of vehicle, so that the vehicle will steering with smaller steering wheel angle compared with conventional vehicle. With this advantage, the vehicle can reach the ideal of turning radius to minimize the wear of tire.
28
Jhuang, Bing-Han, and 莊秉漢. "A Window-Interfaced Modeling and Calculation System of Planetary Gear Train by Applying AutoCAD VBA." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/20630915765712846011.
Full textAbstract:
碩士正修科技大學
機電工程研究所
97
With the great progress of computer technology, parametric computer aided design methodology has been widely applied in many mechanical related industries. Although the planetary gear reducer is widely applied in various mechanical transmission systems, the design work is quite difficult due to its complicated design procedures. In virtue of this reason, this research has developed a three dimensional, parametric, window-interfaced CAD system on AutoCAD platform for the planetary gear reducer. This system allows users to input a planetary gear reducer’s design parameters, such as number of teeth, module, and pressure angle, from the window of human machine user interface. Three dimensional solid models of the planetary gear reducer can be created immediately by the established AutoCAD VBA program. Various performance parameters including diameters of pitch circles, contact ratio, center distances, tooth contact stresses, and tooth bending stresses can also be given out by the program. Simulation of meshing of the planetary gear reducer is realized. Solid models created by the created software can be exported to CAE or CAM software to perform engineering analysis or generate NC manufacturing tool path. The future work of the research is to integrate finite element analysis and measuring task under the same human machine interface to conform the future trend of development.