Epicyclic-type automatic transmissions are widely used in automobiles, it provide different speed ratio by control different elements to be an input or a fixedness with clutches and brakes. There are many researches about the Epicyclic-type automatic transmissions, but the research of the arrangement of clutches and brakes is fewer, and lacked for a method for arranging the desired clutches and brakes quickly. Therefore, the purpose of this research is to develop a methodology for arranging the desired clutches and brakes. First, introduce a planar-graph representation and a number sequence which had been used in arranging desired clutches and brake for years. Second, explore the relationship between contracted graph and epicyclic gear mechanisms based on topology theorem. Then provide a systematical procedure to arrange desired clutches and brakes into epicyclic gear mechanisms. With the above method, can find seven types of feasible clutching sequence that havn¡¦t been discovered in 94 types of feasible clutching sequence. Then, the number of the teeth of all gears can be calculated, as a result, five types of six-speed automatic transmissions are found. Finally, build the model of all the nine-link two-DOF epicylic gear mechanism that can be used in six-speed automatic transmissions.

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.

An epicyclic-type 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. For the development of multi-speed parallel-connected automatic transmission for automobiles, the related configuration design methods are still tedious and prone to human error. Therefore, the purpose of this research is to present an efficient methodology for the systematic design of the parallel-connected automatic transmission for automobiles. First, fundamentals and gear-shifting operations of the parallel-connected automatic transmission are illustrated to establish the design requirements, and the theory of the analysis of speed ratios for epicyclic-type automatic transmission is derived based on the concept of lever analogy. Next, one simple clutching-sequence synthesis methods are proposed and illustrated, based on the lever analogy, and the design theory and the procedure of clutch configuration of epicyclic-type automatic transmission are developed. With the above methods, designs of six-speed and eight-speed parallel-connected automatic transmission. Finally, the complete atlas of six-speed and eight-speed parallel-connected automatic transmission can be systematically synthesized from the data of given speed ratios. This proposed design method can also be applied to the development and design of multi-speed parallel-connected automatic transmissions.

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.

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.

¡@An automatic transmission that is a transmission device between the engine and drive wheel, offers the vehicle while increasing and decreasing the speed mainly. Its job keeps the engine within a certain working rotational speed range.¡@Although there are many epicyclic-type automatic transmissions in production, the related design methods of lever diagram is not well developed.¡@Thus, the purpose of this research is to develop a systematic design of the epicyclic gear transmissions for automobiles with lever diagrammatical methodology.¡@First, fundamentals and gear-shifting operations of the four-speed and six-speed epicyclic-type automatic transmissions are illustrated to establish the design requirements.¡@Second, based on the basic theories of lever diagram, a procedure is applied to kinematic analysis for automatic transmission existed, and set up composite lever diagrams of 13 two-DOF seven-link epicyclic gear mechanisms and 190 two-DOF nine-link epicyclic gear mechanisms.¡@Next, a general clutching-sequence synthesis of lever diagrammatical method are proposed and illustrated. According to the limit range of lever dimensions established for four and five coaxial components, the clutching-sequences and the ranges of basic gear ratio of the feasible gear trains can be derived.¡@Finally, the planar-graph representation for arranging desired clutch and the number of teeth based on lever dimensions are applied to design six-forward speeds automatic transmission. The result of this work shows that the seven-link two-DOF epicylic gear mechanisms, and the nine-link two-DOF parallel-connected epicylic gear mechanisms could reach four- and six-forward speeds at most, respectively.