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Dissertação de mestrado integrado em Engenharia Mecânica, Esta dissertação visa analisar o efeito do desalinhamento do anel exterior de um trem epicicloidal num conjunto de parâmetros de funcionamento habitualmente empregues na caracterização mecânica de engrenagens. Para o efeito, elaborou-se um modelo numérico, pelo Método dos Elementos Finitos, a partir de uma formulação matemática que permite gerar o perfil do dente. O referido modelo permitiu reproduzir corretamente uma parcela significativa do ciclo de engrenamento de um trem epicicloidal simplificado, formado por uma única roda satélite, na ausência de atrito. Os parâmetros de funcionamento foram a pressão de contacto, a área de contacto dos dentes, bem como a força normal e tangencial desenvolvida no contacto entre os dentes. Este estudo permitiu identificar padrões de comportamento nos parâmetros de funcionamento atrás referidos, ao longo da mesma parcela do ciclo de engrenamento. Estes padrões foram posteriormente comparados com os obtidos na condição de desalinhamento do anel exterior, revelando diferenças assinaláveis., This dissertation aims to analyse the effect of the misalignment of a train Epicyclic’s exterior ring in a set of operating parameters commonly used in the mechanical characterisation of gears. For this purpose, a numerical model was elaborated, by the Finite Element Method, from a mathematical formulation that allows the generation of the tooth profile. This model allowed to correctly reproduce a portion of the gearing cycle of a simplified epicyclic train, formed by a single satellite wheel, in the absence of friction. The operating parameters were the contact pressure, the contact area of the teeth, as well as the normal and tangential force developed in the contact between the teeth. With this study is possible to identify patterns of behaviour in the parameters mentioned above, along the same portion of the gearing cycle. These patterns were later compared with those obtained in the misalignment condition of the exterior ring, revealing notable differences., Este trabalho teve o apoio da FCT – Fundação para a Ciência e Tecnologia, através do Programa bilateral com a Tunísia, intitulado “Modelação híbrida para estudo e análise do comportamento dinâmico de sistemas de transmissão mecânica por rodas dentadas”.

[ES] El proyecto consiste en una comparación del tipo de engranaje planetario utilizado en los turbohélices y turbofans, haciendo uso del software KiSSsoft. Incluirá una introducción de los motores actuales que nos encontramos en el mercado (¿State-of-art¿), junto con los engranajes empleados. Se detallará la evolución de los mismos a lo largo de la historia, explicando cómo se fueron desarrollando con el objetivo de buscar la máxima eficiencia, justificando la necesidad de instalar engranajes en ambos motores. Se incluirá una breve explicación de los diferentes tipos de engranajes y la lucha de los ingenieros por buscar un equilibrio entre eficiencia, poco peso, transmisión de par, durabilidad y coste. Finalmente, se incluirá el diseño mediante el software mencionado, de dos tipos de engranajes., [EN] This project is a comparison of Epicyclic Gear Train configurations between Turboprops and GearedTurbofans using the software KissSOFT. It will include an introduction with some the state-of-art engines, together with the gears used. A detailed development of the egines will be explained, always looking for improvements and changes to reach the maximum efficiency, justifying the need of gears in both engines. There will be included a brief explanation about the different types of gears, and the fight among engineers to look for an equilibrium between light weight, high torque, durability and cost. Finally, there will be included a design of the gears using the kissSfot software.

This work is included in a more extended study on small volumetric machines, that are suitable for a developing small solar power plant (1-3 kW). This paper presents both experimental and numerical analysis of an innovative reciprocating compressor. Its main feature is the use of an epicyclic gear to drive the pistons. The first section of the article illustrates the advantages of this design choice. The main advantage is the lack of lateral forces on the piston. The second section of this work focuses on the experimental characterization of the compressor. The experimental tests were performed on several operation points so obtaining the indicator diagrams. The efficiency and the specific work of the studied compressor were compared with data from pertinent scientific literature. Finally, a numerical thermo-fluid-dynamic model developed in MATLABܘ is presented. The model considers thermal exchanges for every compression phase. The numerical data are then compared with the real ones.

This research work was conducted at the Contact and Structural Mechanics Laboratory (LaMCoS) of LaMCoS - INSA Lyon (UMR CNRS 5259) in partnership with Hispano-Suiza (SAFRAN group). In the context of new turbo jet engine developments, a promising technological solution consists in inserting a planetary / epicyclic gear train between the turbine and the propeller which, in theory, can improve the system performance, especially in terms of efficiency. Increasing power densities and mass reduction constraints lead to more compliant structures which need to be analyzed from a dynamic viewpoint. The present work deals therefore with the dynamic modelling of planetary / epicyclic gears and the effects of assembly errors, tooth shape deviations and deformable structural components. A lumped parameter approach has been favored which combines rigid-body gear elements, beam and lumped parameters elements. A thin-slice model has been used to simulate the time-varying elastic properties of gear teeth with an elemental stiffness and a normal deviation functions attributed to every discrete cell on the contact lines (thin slice) and updated at each time step with respect to the meshing course and the instant positions of the teeth. Ring-gear deformations are introduced via a model of elastic annulus discretized into straight beam elements and connected to the gear elements. Double-helical gears are simulated by linking two gear elements of opposite hands by Timoshenko beam elements. The possibility of helix stagger is implemented by shifting the helix positions in the base plane. Finally, the equations of motion are solved step by step in time by combining a Newmark scheme and a normal contact algorithm which makes it possible to account for partial and total instant contact losses. A number of comparisons with benchmark results from the literature are presented which prove that the proposed theoretical and numerical developments are sound and can actually be used to simulate the influence of planet position errors, helix stagger, pitch errors and ring-gear deformations. The optimization of tooth shape modifications, i.e. profile and lead modifications, re dynamic mesh forces in planetary gears is tackled. Using a genetic algorithm, optimum profile modifications are derived and compared with some analytical results in the literature. Their performance over a range of loads and speeds is assessed for helical and double helical gears with rigid and flexible ring-gears. A quasi-static “equivalent” criterion based on local transmission errors is presented and commented upon. Having proved its relevance, a number of results are derived concerning the influence of helix stagger and lead crowning superimposed on optimum profile modifications. Finally, a deformable ring-gear support is introduced using a sub-structuring technique and its contribution in terms of tooth load distribution is examined., Ces travaux de thèse sont le fruit de la collaboration entre la société Hispano-Suiza et le LaMCoS de l’INSA de Lyon. Dans le cadre du développement de nouveaux systèmes de propulsion, l’implantation d’un train planétaire / épicycloïdal entre la turbine et l’hélice semble être une voie intéressante pour atteindre les performances souhaitées en terme de rendement. L’augmentation des puissances transmises et la réduction des masses embarquées dans les applications aéronautiques tendent à rendre les composants de plus en plus déformables. Lors de ces travaux de recherche, un modèle dynamique de trains planétaires a été développé, incorporant les effets des erreurs de montage, des écarts de forme et des sous-ensembles flexibles. Une approche à paramètres concentrés est utilisée, intégrant notamment des éléments spécifiques d’engrenage et des éléments d’arbre. Pour les éléments d’engrenage, le formalisme des fines tranches juxtaposées est employé pour représenter les dentures. Une raideur élémentaire et un écart normal sont attribués à chacune des tranches et sont réactualisés à chaque pas de temps en fonction de la cinématique des composants et des déviations du profil des dentures. Les déformations de la couronne sont introduites à l’aide d’un anneau discret composé de poutres droites couplé aux éléments d’engrenage. Les dentures double-hélice sont modélisées par deux éléments d’engrenage d’angles d’hélice opposés liés par une poutre de Timoshenko. Finalement, les équations du mouvement sont résolues pas à pas dans le temps par un schéma de Newmark combiné à un algorithme de contact normal, permettant de prendre en compte les pertes de contact partielles ou complètes. Dans un premier temps, un certain nombre d’éléments de validation est présenté et comparé à des résultats tirés de la littérature. Afin d’asseoir notre modélisation, l’influence des erreurs de positionnement des satellites, du décalage des hélices, des erreurs de pas et des déformations de la couronne sur les distributions de charge est abordée pour différentes configurations de train planétaire. Dans un deuxième temps, l’optimisation des corrections de denture dans le but de réduire les vibrations est investiguée. Les corrections de profil sont introduites sur les engrènements de façon (i) linéaire et symétrique en tête de dents et (ii) identique pour tous les satellites mais (iii) différente selon le flanc actif. Dans ce contexte, les corrections sont tout d’abord optimisées vis-à-vis des efforts dynamiques d’engrènement à l’aide d’un algorithme génétique. Puis, leurs performances sont analysées en fonction du couple transmis et de la vitesse de rotation. Par la suite, un critère « équivalent » est dérivé, vérifié et utilisé pour étudier l’influence du décalage des hélices et d’une correction longitudinale parabolique sur ces corrections de profil optimales. Enfin, une sous-structure du porte-couronne est introduite et son impact sur les distributions de charge est exploré.

Darbe nagrinėjami elektros varikliais valdomi planetiniai reduktoriai - variatoriai. Atliktos mokslinių straipsnių analizės metu susipažinta su įvairių rūšių automobiliuose naudojamomis transmisijomis: pateikta jų klasifikacija, apžvelgtos dažniausiai naudojamos transporte pavarų dėžės. Pateikta tyrimo metodika, apžvelgti eksperimentinių tyrimų įrenginiai ir priemonės. Atlikti elektros varikliu valdomo planetinio reduktoriaus eksperimentai su suprojektuotu tyrimo stendu. Palygintos belaipsnės pavarų dėžės su parinktu dyzeliniu varikliu, bei pateiktos išvados ir rekomendacijos. This thesis analyzes the electric motor which controlled by planetary gearboxes - variator. Accomplished scientific articles during the analysis been familiarized with different kinds of transmissions which used in vehicles: submitted their classification, reviewed most commonly gearbox which used in transport. Submitted research methods, an overview of experimental research equipment and facilities. Performed experiments of electric motor controlled by planetary gear with designed study stand. Were was compared continuous variable transmission with a selected on diesel engine, submitted conclusions and recommendations.