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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

An Experimental study on identification of planetary gear train system by Using Genetic Algorithms

Liu, Kun-Nan 04 July 2001 (has links)
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.
2

A Study on the Creative Design Methodology of the Multi-Speed Drive Hub for Bicycles

Shu, Jiun-jung 02 July 2007 (has links)
The multi-speed internal gear hub of a bicycle is a well-closed gear shifting system that works perfectly under any challenging riding environment, and is developed specifically to improve fragile chain-drive derailleur using planetary gear trains. In recent years, bicycle internal hub gears have been developed toward multi-speed transmission, and in the development process of internal gear hubs, the structure of speed changing mechanism has changed from a single planetary gear train to multiple planetary gear trains, and is becoming more complex. The primary purpose of this Study aims to establish a systemized and efficient design process, and develop an effective theory and method for designing multiple-speed internal gear hubs with the design concept and common features of multiple-speed internal gear hub products developed in recent years, to favor the innovation and development of internal gear hubs. First, existing multiple speed internal hub products are analyzed and summarized for their basic features, limitations, and demands as the reference for the design of multiple speed internal gear hubs, and a catalog of usable planetary structures is systematically established with the coupling and connection of basic high and low ratio speed changing modules. Secondly, usable planetary structures that offer best performance of geometric progression speed ratio distribution of gear hub are matched with gear positions, and a table of gear sequence is confirmed; third, based on the maximum external diameter required by design, tooth numbers for every gear in a hub are defined according to the relationship between tooth number and speed ratio, as well as the gear sequences; and finally, the systematic design process above is applied to the development of an easy-to-use computer aided design software with the lowest possible number of variables using Visual Basic 6.0 for designers, in order to favor the innovation and development of internal gear hubs.
3

Constant Speed Mechanism of Planetary Gear Train

Lin, Feng-Tien 12 September 2007 (has links)
In current years, searching for substitute energy such as the wind and ocean power of renewable energy is an important subject due to the petroleum shortage. The gear box is the key mechanism in the system of wind and ocean power. Moreover, the main function of the system is to generate electricity by speeding up the rotative velocity. However, the power of environment changes momentarily and makes the turbine a variable input. In order to improve the efficiency of generating electricity, it should get the constant input to keep the high quality of generating electricity. First of all, the study focuses on the gear box and synthesizes a constant speed mechanism of planetary gear train which degrees of freedom is two. In the mechanism, inputs are the variable speed turbine and a constant speed motor. When they input the mechanism, a constant speed output will be made to supply the generator. Secondly, it is necessary to set up the real object of the constant speed mechanism of planetary gear train. Finally, observing the real condition from the experiment to prove the theory is correct.
4

Experimental Verification for the Independently Controllable Transmission Mechanisms

Lin, Chung-chi 21 February 2011 (has links)
In current years, renewable energy is an important topic due to the energy crisis and the environments protection issue. One of the renewable energies, wind power has the advantage of high popular rate, convenient, and clear. But there are disadvantages can be improved. The generator has a low quality of output because the variety of wind speed, and it needs electronic equipment to maintain the quality of energy output. According to the research results of Dr. Hwang, using the independently controllable transmission mechanisms that has a controllable output could improve the quality of generator output in Wind Turbines. In this study, the tests platform of independently controllable transmission mechanisms will be fabricated. And analysis the kinematics and dynamics by experimental results to demonstrate the feasibility in wind turbine applications of independently controllable transmission mechanisms.
5

Power Flow Analysis on the Dual Input Transmission Mechanisms of Wind Turbine Systems

Hsiao, Hsien-yu 21 July 2011 (has links)
Two parallel planetary gear trains design are proposed to construct a dual input transmission mechanism system used in small power wind turbine systems. The time varied input wind powers are applied in the system with specified speed and torque. The Dynamic power flow variation in gear pairs are modeled and simulated in this work. Results indicate the proposed planetary gear train system is feasible in wind turbine system. The effect of gear train parameters on the operation safety and life will also be studied. The dynamic torque equilibrium equations between meshed gear pairs are employed to model the dynamic torque flow in this proposed dual input gear system. The nonlinear behavior of a synchronous generator has also included in the modeling. The dynamic responses of the dual input transmission mechanism system are simulated by using the 4th order Runge-Kutta method. The effect of system parameters used in this wind turbine system, i.e. the wind speed, the magnetic flux synchronous generator, the inertia flywheels, on the output electrical power variation have investigated in this study. The strength analyses of gear pairs with the bending fatigue and surface durability consideration have also studied in this work.
6

Experimental Verification for the Power-Flow of the Parallel-type Independently Controllable Transmission Mechanisms

Liao, Wei-Hsiang 28 June 2012 (has links)
A parallel-type independently controllable transmission mechanism (PT-ICT) comprises of two planetary gear trains and two transmission-connecting members. It also includes an input shaft connecting to the input power source, a controller shaft connecting to the controller, an output shaft connecting to the output end, and a free-transmission end connecting to a secondary input source or output end. The controller can independently manipulate the transmitted output speed that is not affected by the variation of the Input speed. Adjusting the free-transmission¡¦s torque can reduce the power of the controller. This study proposes a new structural arrangement of the PT-ICT, and a corresponding test-bed for kinematic and dynamic experiments is also constructed. It first analyzes the theoretical expressions of angular speeds, torques, and power flows introduced on each rotational shaft. And then for the purpose of verifying the validity of the analytical theoretical results, this study also builds a 3D model configuration with its prototype of the PT-ICT is also built to perform kinematic and dynamic experiments. It shows that experimental results are in agreement with the design values. It is expected that applying the proposed PT-ICT mechanism to wind turbines in a variable wind farm can achieve high quality electricity output, extend workable wind speed range, and have no need of using any frequency converters.
7

Design of Distributed-Flow-Type Multi-Speed Hubs for Bicycles

Wen, Tzu-chuang 01 September 2008 (has links)
The planetary gear train are applied in multi-speed drive hubs for bicycles. Since a multi-speed drive hub has the advantages of the small volume and stable gear shifting, it is used widely in folding bicycles and electric bicycles. The distributed-flow-type multi-speed hubs could provide more gears, the related design theory is not well development. Thus, the purpose of this research is to develop a systematical methodology for the design of the distributed-flow-type multi-speed hub for bicycles. First, an existing patent is analyzed to identify the basic characteristics and the requirements of the multi-speed hubs. Based on the basic characteristics and the requirements, a systematical procedure is proposed to synthesize the feasible concepts of the planetary gear trains. Second, another procedure is proposed to determine the feasible clutching sequence tables. Third, the difference in value of the angular velocity is assigned to calculate the gear ratio and to determine the numbers of the teeth of all gears. Finally, the shifting-gear system in the multi-speed drive hubs is designed and arranged. The evaluation of the multi-speed drive hubs is proceeded to select the better alternatives. The result of this work obtains twenty-senven types of the distributed-flow multi-speed hubs for bicycles, three of them could reach sixteen speeds.
8

Computer-Aided Design Software for Torsional Analysis

Griffin, Timothy R. 23 March 1998 (has links)
The goal of this research has been the development of an effective design tool for torsional analysis. In the hopes of achieving this goal the computer program, Torsion 1, has been created. This torsional transfer matrix program provides the user with the ability to easily model multi-rotor systems using a simple user-interface. The program is capable of modeling such components or system characteristics as continuously distributed mass, viscous and structural damping, vibration absorbers, and gear meshes with gear tooth flexibility. The analysis capabilities of the program include forcedresponse and free-vibration analyses. The forced-response analysis module is capable of determining a system’s response to a static or harmonic torsional load. The free-vibration analysis module allows is capable of determining the eigenvalues and eigenvectors for damped and undamped systems. This thesis includes an explanation of the multi-rotor transfer matrix technique employed in Torsion 1. The derivation of transfer matrices for visco-elastic vibration absorbers, pendulum absorbers, flexible gear meshes, and planetary gear trains are included in this work. Finally, the validity of the program results is verified with a set of benchmark examples. / Master of Science
9

差動遊星歯車機構の駆動特性の解明に関する研究 / サドウ ユウセイ ハグルマ キコウ ノ クドウ トクセイ ノ カイメイ ニカンスル ケンキュウ

中川 正夫, Masao Nakagawa 22 March 2019 (has links)
本研究では,差動機構としてニーズが高まりつつある遊星歯車機構に関して,回転伝達メカニズムの解明および振動騒音の低減にむけた駆動特性の解明を目的に体系的に研究をおこなった.軽負荷な回転伝達系としての差動遊星歯車機構を扱い,座標系や記号,瞬間中心の定義に基づき,PLC制御を用いた再現性の確保された試験機を用いて評価をおこない,Bond graphを用いたシミュレーション,ハイスピードカメラを用いた過渡応答の観察,および異なる歯面精度を組みあわせた振動騒音への影響の考察をおこなった. / 博士(工学) / Doctor of Philosophy in Engineering / 同志社大学 / Doshisha University

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