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.

This thesis presents a unification of kinematic and force-based methods for the design and analysis of planetary gear trains along with a discussion of potential applications in tandem biking. Specifically, this thesis will provide a simple solution technique for the general case of a two-degree of freedom (2DOF) planetary gear train along with new graphical design aids. It will also address the use of epicyclic gear trains as a power coupling in a tandem bike. In the current literature, planetary gear trains are given a clear treatment with regard to the pure kinematics of the system, but little or no literature exists that includes the torques present in the system. By treating both the kinematics and torque balance of the most general case, this thesis attempts to fill a void in the current literature. After developing the solution to the general two-degree of freedom case using the Willis formula, a force analysis will be performed using the conservation of energy principle assuming zero losses. Once the total solution is known, nomographs will be presented as a simple design tool. These graphical aids enable the designer to simultaneously approximate both speeds and torques for the mechanism. After fully developing a satisfactory solution technique and design tools, these will be applied to the problem of coupling the power provided by the riders of a tandem bicycle. / Master of Science

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.

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.

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.

Aircraft control mechanisms, such as those that operate the flaps, ailerons, rudders, etc., are almost exclusively driven by hydraulic-based systems. Their popularity in flight control systems is not unfounded; hydraulic actuators are quite torque-dense and benefit from decades of development bringing operating performance to a high level. On the other hand the infrastructure to support this system increases weight, adds system development complexity, and reduces aircraft maintainability [Jensen et al, 2000]. Based on recent Electro-Mechanical Actuator (EMA) development and design efforts at the Robotics Research Group (RRG), a new opportunity exists to replace current hydraulic flight control systems with those powered by electricity through a national program [Tesar, 2005]. A literature review of the topic found a 30 year old effort by AiResearch to develop a similarly powered hingeline actuator with given traditional performance goals (torque capacity, redundancy, output speed, reliability). In this report,a thorough analysis is performed on each major component group to quantitatively evaluate this baseline device. Using component technologies developed at RRG, this report proposes a dual torque-summing electromechanical actuator, each with a star compound / hypocyclic combined gear train, designed to exceed the performance of the original (1976) AiResearch project. This preliminary design exercise includes a layout of the entire actuator along with an appropriate analysis of major components including bearings, gear train, motor, housing, and release mechanism. The performance of this gear train is critical to overall actuator success and fundamental analytics have already been developed in this area [Park and Tesar, 2005]. Finite Element Analysis on the gear train and housing provide early design feedback and verification of actuator performance characteristics. In particular, simulation results show the gear stiffness, load sharing, and torque capacities exceed analytical estimates. Finally, four different comparisons are presented that evaluate configuration variations of the two designs based on applicable performance criteria. Results show the RRG fault-tolerant actuator has a marked improvement over the baseline in average stiffness (14.2x), reflected inertia (3.2x) and nominal torque density (3.4x). The chapter next lists actuator test methods and aircraft qualification standards. Finally, a summary of future work is detailed in a ten step outline to bring this EMA technology to a level of early deployment in a large range of aircraft systems.

There are many advantages of Epicyclic gear type automobile transmissions. It is composed more densely and weights lighter. It provides higher gear ratio and can transmit power differentially. Therefore, this type of transmissions are applied to almost every automobiles in recent years. However, the design process of an Epicyclic gear type automobile transmission is more complicated than Counter shaft type one. In the world, there are just two kinds of 8-speed Epicyclic gear type automobile transmission in production. This study introduced a design methodology of Parallel epicyclic gear type automobile transmission by decomposing and recomposing of Lever diagram. First we drew the Lever diagram from given rotation speed ratios. Next we listed all 3-point lever diagrams which are decomposed from the original Lever diagram, and deleted those with unreasonable value of K. Then we listed all combinations of 3-point lever diagram which composed the original Lever diagram, and we got all feasible epicyclic gear train mechanisms. After choosing feasible epicyclic gear train mechanism, we set up necessary clutches and breakes in clutch graphs. Finally, based on the clutch graph, we draw the schematic diagram of mechanisms, and embodies out results. Methodology of this study is better than old ones because our methodology based on Lever diagram did not need to find the usable mechanisms from the catalog of epicyclic gear train mechanisms. Thus, the new methodology simplifies the process of designing a epicyclic gear type automobile transmission.

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.

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.

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.