Thesis (Ph. D.)--University of Nevada, Reno, 2006. / "December, 2006." Includes bibliographical references (leaves 129-135). Online version available on the World Wide Web.

An epicyclic gear mechanism for automobile transmissions 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 gear mechanisms for automobile transmissions in production are mostly Ravigneaux-type, Parallel-connected type and Lepelletier epicyclic mechanisms, and the Lepelletier epicyclic gear mechanisms is a device which is connected with a simple epicyclic gear mechanism besides the input end to increase the total number of speed ratios of an automatic transmission. For the incompletion in the relative design methodology, a systematic methodology of designing Lepelletier epicyclic gear mechanisms for automobile transmission is described. At first, fundamental and gear-shifting operations of the Lepelletier-type automatic transmissions is introduced, and the basic principles of lever analogy is explained, the gear ratio¡¦s analysis for Lepelletier epicyclic gear mechanisms is illustrated to establish the design requirements. Secondly, gearing-sequence is devised base on the lever analogy diagrams, and a systematical procedure to arrange desired clutches and brakes into epicyclic gear mechanisms is provided, then the number of the teeth of all gears can be calculated. At last, the six-speed and eight-speed Lepelletier automatic transmissions are designed base on the above design procedure. The results of this work obtain 19 types of automatic transmission which could reach six-speed.

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.

Epicyclic-type automatic transmissions are used in automobiles widely. There are many advantages of epicyclic-type automatic transmissions. It is composed more densely, smaller and provide higher gear ratio. We can get different output speed by actuating different clutches or brakes. There are a lot of patents for epicyclic-type automatic transmissions, but most of them tends to be three degrees of freedom automatic transmissions or using embedded clutches or brakes and other complex constructions. It is a better choice if we could use relatively simple manufacturing and control of two degrees of freedom and external clutches and brakes in the same multi speeds, speed ratio of the same premise. Therefore, this study aims to propose a set of design process for two degrees of freedom parallel-connected epicyclic gear automatic transmissions and computerize the process. First, we established the lever diagram for eight-speed automatic transmissions. By decomposing lever diagrams to all possible three-point lines, then composing four different lines to get all possible eight-speed automatic transmission constructions. Then, we use direct-member -number method to get member number of all constructions. Determining the possibility of configuring clutches and brakes, excluding the construction which can¡¦t configure the clutch and brake, establish the database can be configured. Finally, we determine a speed ratio for the eight-speed automatic transmissions, excluding the constructions doesn¡¦t match the appropriate gear ratios. Drawing the diagram which comply the restriction for eight-speed automatic transmissions. Keywords: automatic transmission, lever diagram, direct-member-number method, member number, configuration of clutches

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 a model is developed for calculating the loads on the wetclutches in apowershift transmission. This thesis was done at Volvo CE in Eskilstuna and is focusedon their 4-speed countershaft transmissions. The goal of the project is to be able tocalculate the loads automatically during the transmission tests and thus acquire increasedknowledge about what occurs during operation.The model was developed by first generating a number of concepts and then evalu-ating them to decide which one should be developed further. The chosen concept wasthen developed further and implemented into the test equipment as a calculation script.The chosen loads to model were the energy absorbed in each clutch, the coefficient offriction (COF) and the slip distance. The COF was later found to give too unreliableresults to be used in any other way than as a benchmark for how well the model wasconfigured and to see any large changes in COF.The model was validated by calculating the energy absorbed in a HTE-200 seriestransmission and comparing it to a reference calculation model. It was seen that theresults from the new model are very close to the reference result. The energy lostcalculated by the new model will be equal to 94 % of the energy lost calculated by thereference model, but only when measuring the inertia phase. The energy lost is equalto 135 % when the torque phase is included. The increasing difference is believed tobe because of an error in the reference model that means it does not cover the torquephase.

Typescript. Includes vita and abstract. Bibliography: Includes bibliographical references (leaves 63-68). Description: viii, 68 leaves : map ; 29 cm. / The ability of the Pigeon Guillemot Cepphus columba to rear an additional chick was tested by manipulating clutch sizes. The effect of the manipulations on growth, and hatching, fledging, and egg success was measured in chicks from experimental, natural, and control nests. No significant differences were observed between the nest types. Data from 1983, 1984, 1985, and 1989 were analyzed for potential differences in reproductive success of one and two egg clutches. The ratio of one to two eggs was significantly higher in 1985 and 1989. Hatching and fledging success was significantly higher for two egg clutches in 1985 and 1989. No significant differences were observed for egg success. Egg volume was significantly greater in two egg clutches in 1983 and 1984. Egg volume was correlated with fledging but not with hatching success.

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Thesis (Ph. D.)--University of Montana, 2006 / Title from PDF title page (viewed on Mar. 18, 2007). Includes bibliographical references.

An automatic transmission is a device that is connected to the back of an engine and sends the power from the engine to the drive wheels. Its job is to keep the engine within a certain angular velocity. Although there are many epicyclic-type automatic transmissions in production, the related configuration design methods are still tedious and prone to human error. A simple and analytic methodology needs to be developed. Therefore, the purpose of this research is to present an efficient methodology for the systematic design of the epicyclic gear transmissions for automobiles. First, fundamentals and gear-shifting operations of the four-speed, five-speed and six-speed epicyclic-type automatic transmissions are illustrated to establish the design requirements. Second, based on the kinematic equations of the fundamental geared entities and the corresponding basic gear ratios, a procedure is applied to execute the kinematic and mechanical-efficiency analyses for the automatic transmissions. Third, two simple clutching-sequence synthesis methods are proposed and illustrated. One is based on the speed ratio equations, and another is based on the lever diagram. Next, a planar-graph representation is presented to arrange the desired clutches for each possible clutching sequence into the epicyclic gear mechanism. Then, the number of teeth of each gear is synthesized from assigning two or three desired speed ratios by the analytic method. Finally, a computer-aided design program for the clutching-sequence synthesis is developed with the considerations of the design requirements. With the above methods, the systematic designs of the 204 epicylic gear mechanisms are given for demonstrating the feasibility of the proposed methodology. The result of this work shows that the seven-link two-DOF epicylic gear mechanisms, the eight-link two-DOF Ravigneaux gear mechanism, and the nine-link two-DOF parallel-connected epicylic gear mechanisms could reach four-, six-, and six-forward speeds at most, respectively.