An epicyclic-type automatic transmission is a device which is connected from the engine to the driven wheels. A Lepelletier automatic transmission consists of a two-DOF epicyclic gear mechanism and a fundamental geared entity, which can provide more speed ratios. For the development of automatic transmission with eight or more speed ratios, an efficient design methodology is urgently needed and still not available. Therefore, the purpose of this article is to develop a systematic method for the design of Lepelletier automatic transmission. First, the features and requirements of the Lepelletier automatic transmissions are investigated and the corresponding design requirements are induced. Next, the theory of the analysis of speed ratios for Lepelletier automatic transmission is derived based on the concept of lever analogy. Then, the design theory of Lepelletier automatic transmission is developed based on the analysis theory. Finally, the complete atlas of six-speed and eight-speed Lepelletier automatic transmissions can be systematically synthesized from the data of three given speed ratios. In this article, the innovative and patentable six-speed and eight-speed Lepelletier automatic transmissions with the simplest structure have been. This proposed design method can also be applied to the development and design of ten-speed Lepelletier automatic transmissions.

No description available.

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.

No description available.

Hyundai, Toyota and GM automobile factory were committed to provide more speed planetary gear automatic transmission research and development in order to improve the transmission performance and fuel efficiency. To set embedded clutch into planetary gear mechanism is an effective way to get more speed ratio, its call an epicyclic-type automatic transmission with embedded clutches, referred to the embedded-type automatic transmission. For the development of automatic transmission with eight or more speed ratios, an efficient design methodology is urgently needed and still not available. Therefore, the purpose of this article is to develop a systematic method for the design of automatic transmission with embedded clutches. First, the features and requirements of the automatic transmissions with embedded clutches are investigated and the corresponding design requirements are induced. Next, the theory of the analysis of kinematic for automatic transmissions with embedded clutches is derived based on the concept of lever analogy. Then, the design theory of automatic transmissions with embedded clutches is developed based on the analysis theory. Finally, the complete atlas of automatic transmissions with embedded clutches can be systematically synthesized from the data of given speed ratios. In this article, the innovative and patentable seven-speed and eight-speed automatic transmissions with embedded clutches have been done. This proposed design method can also be applied to the development and design of ten-speed automatic transmissions with embedded clutches.

The Hybrid Electric Vehicle Team (HEVT) of Virginia Tech is one of 16 university teams participating in EcoCAR 3, the latest competition in the Advanced Vehicle Technology Competitions (AVTC) organized by Argonne National Labs. EcoCAR 3 tasks teams with converting a 2016 Chevrolet Camaro into a hybrid electric vehicle with 5 main goals: reducing petroleum energy use and greenhouse gas emissions while maintaining safety, performance, and consumer acceptability. Over the last 4 years, HEVT has designed and built a plugin parallel hybrid electric vehicle with a unique powertrain architecture. This work deals with utilizing the unique powertrain layout of the HEVT Camaro to improve drive quality, a key component in consumer acceptability. Although there are many ways to approach drive quality, most aspects can be analyzed in the smoothness of the vehicle longitudinal acceleration response. This research is focused on improving the drive quality of the vehicle developed for EcoCAR 3. Multiple algorithms are developed to address specific aspects of drive quality that can only be done with the powertrain developed. This begins by researching the control strategies used in modern automatic transmissions, and moves into the modeling strategy used to begin algorithm development. Two main strategies are developed and calibrated in the vehicle. The first being a strategy for reducing jerk in pure electric mode by limiting motor torque response. The second strategy aims to improve transmission shift quality by using the electric motor to reduce torque fluctuations at the driveshaft. The energy consumption impact of both of these strategies is also analyzed to ensure that drive quality does not come at the large expense of energy consumption. / Master of Science / The Hybrid electric vehicle team (HEVT) of Virginia Tech is one of 16 university teams participating in EcoCAR 3, the latest competition in the Advanced Vehicle Technology Competitions (AVTC) organized by Argonne National Labs. EcoCAR 3 tasks teams with converting a 2016 Chevrolet Camaro into a hybrid electric vehicle with 5 main goals: reducing petroleum energy use and greenhouse gas emissions while maintaining safety, performance, and consumer acceptability. Over the last 4 years, HEVT has designed and built a plugin parallel hybrid electric vehicle with a unique powertrain architecture. This work deals with utilizing the unique powertrain layout of the HEVT Camaro to improve drive quality, a key component in consumer acceptability. Multiple strategies were examined and implemented for different driving conditions, and ultimately an improvement was made. However, new challenges are introduced by having some components remain stock that limit the success of smoothing gear shifts.

Im Vortrag werden die komplexen und teilweise konträren Herausforderungen an zukünftige automobile Antriebsstränge und Getriebesysteme vorgestellt. Die klassische Suche nach neuen Antriebssträngen, basierend auf Intuition und Expertenwissen, kann diesen vielseitigen Zielstellungen kaum noch gerecht werden. Aus diesem Grund wird ein neuer methodischer Ansatz vorgestellt, mit dem konventionelle und hybride Getriebekonzepte rechnergestützt generiert werden können. Die Voraussetzung dafür bildet die eindeutige und kompakte mathematische Abbildung von beliebigen Getriebesystemen oder ganzen Antriebssträngen im Computer auf Basis eines Wellenmodells. Diese Codierung lässt sich effizient hinsichtlich diverser kinematischer und kinetischer Belastungen für frei wählbare Freiheitsgrade analysieren. Die rechnergestützte Synthese und Bewertung neuer Getriebe wird am Beispiel von Planetenautomatikgetrieben vorgestellt, wobei alle kombinatorisch möglichen konventionellen und hybriden Systeme Beachtung finden. Beispielsweise werden für eine aktuell typische Anzahl an Planetenradsätzen und Schaltelementen mehrere hundert Milliarden Getriebevarianten untersucht. Am Ende eines Syntheselaufs werden dem Entwicklungsingenieur die besten Systeme in einem Ranking vorgeschlagen. Der Vortrag schließt mit der Vorstellung exemplarischer Ergebnisse dieser neuen Entwicklungsmethode. Das neue Achtgang-Hybrid-Automatikgetriebe und das neue Neungang-Hybrid-Doppelkupplungsgetriebe verdeutlichen die Entwicklungspotentiale zukünftiger Getriebesysteme, bei denen hochfunktionale und effiziente Eigenschaften mit kleinstmöglichem mechanischem Aufwand, geringen Kosten und Bauraum kombiniert werden. Die IAV GmbH nutzt dieses Entwicklungstool erfolgreich zur Erzeugung von verschiedenen Getriebearten, wie Planetenautomatikgetrieben, Doppelkupplungsgetrieben, Handschaltgetrieben und stufenlos leistungsverzweigten Getrieben mit mechanischem oder elektrischem Variator.

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.

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 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.