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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

The solution of the equations of motion of an aircraft fuselage-landing gear configuration during landings is of interest to the designer who must predict the landing loads which an airplane encounters in service. In general such solutions are difficult because of the highly nonlinear characteristics of the oleo-pneumatic shock strut which couples the lower mass of the landing gear to the fuselage. In the past, attempts to obtain solutions by linearization of these shock strut characteristics have resulted in unrealistic predictions of landing gear motions. Therefore, it has been necessary to carry out most of the theoretical analysis associated with landing gears by means of numerical integration procedures. These numerical methods are tedious, and as a result a large portion of design work has been carried out by means of trial and error drop testing of a system of masses representative of an airplane and landing gear. This in turn has proved to be time consuming and expensive. This paper presents a method for obtaining an analytical solution of the equations of motion for a basically nonlinear system which closely resembles an actual airplane and landing gear configuration. The nonlinear system considered has two degrees of freedom and is composed of a large mass representative of the fuselage-wing combination connected by an oleo-pneumatic shock strut to a wheel. The shock strut is assumed to have velocity-squared hydraulic damping and coulomb friction forces on the strut bearings. The nonlinear spring characteristic of the tire is represented by a sectionally linear spring. In the first part of this paper the equations of motion for this nonlinear system are derived making use of a few simplifications which previous papers have shown to be justified. Also, the degree to which these assumptions limit the results is discussed. Next these equations of motion are solved in analytical form by a method which may be called "equivalent non linearisation." It is shown that this solution is exact only for a specific combination of impact parameters, but that for a wide range of parameters the solution describes the motion of the system adequately for design purposes. Finally, a few analytical solutions are compared with solutions obtained by numerical integration methods; and the results are compared with experimental data for a typical impact. / Master of Science

The main purpose of this report was to test several common viscoelastic polymers and identify key attributes of their applicability to a small aircraft landing gear system for improved damping performance. The applied viscoelastic damping treatment to the gear was of a constrained layer type, promoting increased shear deformation over free surface treatments, and therefore enhanced energy dissipation within the viscoelastic layer. A total of eight materials were tested and analyzed using cyclic loading equipment to establish approximate storage modulus and loss factor data at varying loading frequencies. The three viscoelastic polymers having the highest loss factor to shear modulus ratio were chosen and tested using a cantilever beam system. A Ross, Kerwin, and Ungar analysis was used to predict the loss factor of the cantilever beam system with applied treatment and the predictions were compared to experimental data. Customer requirements often govern the scope and intensity of design in many engineering applications. Limitations and constraints, such as cost, weight, serviceability, landing gear geometry, environmental factors, and manufacturability in regards to the addition of a viscoelastic damping treatment to a landing gear system are discussed. Based on results found from theoretical and experimental testing, application of a damping treatment to a small aircraft landing gear system is very promising. Relatively high loss factors were seen in a cantilever beam for simple single layer constrained treatments for very low strain amplitudes relative to strains seen during loading of the landing gear. With future design iterations, damping levels several times those seen in this document will be seen with a constrained treatment applied to a landing gear system. / Master of Science

The correct tribological design will have a considerable effect on a gear’s service life and efficiency. The purpose of this thesis is to clarify the impact of variation in the gear tooth flank tribological system on the gear contact load capacity – to increase the understanding of how surface topography and lubricant interact. In this thesis the variation in surface topography inherent in the manufacturing method has been shown, by experimental work and computer simulations, to be an important factor for the contact condition in the early life of gears. Surface analysis revealed that the formation and composition of surface boundary layers depends strongly on the chemical composition of the lubricant, but also on pre-existing surface boundary layers. Additionally, surface boundary layers play a major role in frictional behaviour, wear and in allowing the lubricant to react properly with the surfaces. Paper A presents the current ISO 6336 calculation of surface durability. A robust design approach was used to investigate the extent to which the current standard for calculation of surface durability allows for manufacturing variations and the choice of lubricant. Paper B investigates the extent to which a logarithmical profile modification can increase gear contact pressure robustness compared to traditional lead profiles for gears. Paper C compares different gear manufacturing methods and their as-manufactured (fresh unworn) surface topographies, using measured surface topographies as input to a contact simulation program. Paper D examines surface boundary layer formation and the corresponding wear in relation to different anti-wear additives in an environmentally adapted base oil. Papers E and F make use of specimens with surface topographies imitating two gear manufacturing methods (grinding and superfinishing) to be used in a twin-disc and barrel-on-disc machine respectively. The contacts are analysed by friction measurements and simulations combined with methods for surface analysis. / <p>QC 20120925</p>

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.

An epicyclic-type automatic transmission is a device which is connected from engine to driving wheels, and the main purpose is to maintain the revolution speed of engine to be in a desired working range while accelerating or decelerating the automobile. The epicyclic -type automatic transmissions in production are mostly Ravigneaux-type epicyclic mechanisms, and in recent year, the development of automatic transmissions for automobile is oriented to the orientation of setting an single epicyclic gear mechanism instead of the input to bring various inputs of revolution speed to increase the total number of speed ratios of an automatic transmission, and such type of epicyclic is called combinational epicyclic-type automatic transmissions for automobiles. For the incompletion in the relative design methodology, a systematic methodology of designing mechanism and clutching-sequence of combinational epicyclic-type automobile transmission is described. First, fundamental principle of the combination and operations of automatic transmissions are analyzed to establish the design requirements. Second, a procedure of structure synthesis of combinational epicyclic-type automobile transmission is brought up which the planar graphic method is applied for. Third, based on Speed Ratio Relationship of each clutching sequence, a procedure of gearing-sequence is introduced. Finally, on the basis of the analytic method, the teeth of gears is to be clarified. The result of this work obtains five types of the combinational epicyclic-type automatic transmissions which could reach six speeds.

In this thesis, we deal with the design of a shock absorber variant for the type of main landing gear design of the aircraft WT10 Advantic. Then we focus on the design of the selected variant of the main landing gear. Next, we follow regulation CS-23 demands to calculate the load cases for the selected main lending gear. Then we design shock absorber based on the load during landing. We compile the equation of motion of the aircraft, which describes motion of the aircraft during landing, then we compute the equation. Finally, we focus on a stress analysis of the main landing gear and the shock absorber.

This diploma thesis deals with designing electric vehicle gearbox. Gearbox should serve as virtual replacement for actual transmission of VW ID.3 EV. Designed gearbox has two gears. In the first section there is an extensive search processed of drivetrain and transmission of battery electric vehicles. Next section contains choice of transmission concept and analyses solving of individual structural nodes – gear wheels, band breaks (components that engage individual gears), carriers, shaft, bearing. In the conclusion of diploma thesis, the two-gear planetary transmission is evaluated.