Orientador: Robson Pederiva / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-26T21:11:27Z (GMT). No. of bitstreams: 1 Chagas_ClodoaldoBorges_M.pdf: 26402874 bytes, checksum: d4bfb8b718bb540f2313823b84724082 (MD5) Previous issue date: 2015 / Resumo: Os sistemas de transmissão por correntes são umas das principais formas de se transmitir torque e potência entre eixos paralelos. A confiabilidade dos sistemas de transmissão por corrente na sincronização do eixo de manivelas e do eixo de comando de válvulas nas aplicações automotivas tem permitido seu emprego durante toda a vida útil do motor. A aparente vantagem no uso dos sistemas de corrente esconde algumas características indesejáveis inerentes a esse tipo de transmissão. Alguns fenômenos físicos como a "Ação Poligonal" a qual faz com que ocorra flutuação da razão entre as velocidades angulares do eixo movido e motriz, mesmo quando o eixo motriz está em velocidade angular constante, puderam ser modelados por meio da analise cinemática e validados experimentalmente em situações "quasi-estáticas". As guias de corrente são inicialmente elementos cuja principal função é atenuar as vibrações transversais da corrente. No entanto, o estudo desenvolvido constatou a guia como sendo um importante mecanismo cuja posição e geometria podem minimizar a flutuação da razão entre as velocidades angulares. Outro importante aspecto aponta a necessidade da existência de elementos com a capacidade de permitir um auto ajuste de posicionamento durante o ciclo de engate de um elo de corrente. Compreender o carregamento aplicado pela corrente sobre a guia tensora torna possível predizer o estado de tensão deste componente bem como o coeficiente de atrito entre corrente e guia. A interação dos resultados teóricos e experimentais puderam ser introduzidos em um software comercial de elementos finitos para determinação do estado de tensão da guia. Os resultados da extensometria aplicada na guia de corrente foi confrontada aos resultados deste software a fim de obter a validação dos modelos desenvolvidos no presente trabalho. O estudo dos modelos matemáticos em paralelo aos experimentos guiam o desenvolvimento do presente trabalho / Abstract: The chain transmission systems are among the most important ways to transfer power and torque between parallel axes. The reliability of the chain transmission systems for synchronizing the crank shaft and command shaft in the automotive engines allows that this type of transmission system can be employed during the whole life of the passenger car engine. This apparent advantage in the use of the chains hides some undesirable characteristics which are inherent to this kind of discrete system. Some physical phenomena such as cinematic analysis of the "Polygonal Action" which makes the ration between angular velocity of driven and driving axis fluctuate during a chain link engagement, even when the velocity of the driving shaft is at constant angular velocity. This fluctuation was modeled and experimental tests were carried out to validate the model for "quasi-static" situations. The chain guide and chain blades are initially elements which the main function is to hold the transversal vibration of the chain. The present study identified the chain guide profile and assembly position as an important helping component to minimize the fluctuation of angular velocity ratio between sprockets. Another important feature of the transmission system picks up the necessity of at least one of the system components has to be able to self-adjust during the engagement cycle. The comprehension of the contact forces which loads the chain blade by the chain becomes possible understanding the stress state of this component and determine the friction coefficient between chain and blade. The interaction of theoretical and experimental results were introduced as incomes at commercial finite element software to determine the stress state of this component. The measurements of the extensometers were compared to the commercial software to validate the mathematical models and simplification adopted in the present work. The mathematical model in parallel to the experimental procedures drive the development of the present work / Mestrado / Mecanica dos Sólidos e Projeto Mecanico / Mestre em Engenharia Mecânica

Im Beitrag sind Überlegungen hinsichtlich der optimalen Geometrie des Kettengliedes dargestellt. Daraus wurde ein Innenglied mit zwei gewickelten Einlegern entwickelt. Das äußere Kettenglied entspricht dem einer Rollenkette. Die Geometrie der Einleger wurde mithilfe der FEM optimiert, sodass durch zwei Einleger aus Glasfaser die Dehnung auf ca. 57% bzw. für Kohlefaser auf ca. 39% reduziert werden konnte. / The article presents considerations regarding the optimal geometry of chain links. From this, an inner link with two wound inserts was developed. The outer chain link corresponds to that of a roller chain. The geometry of the inserts was optimized by a FEM analysis. With two inserts it is possible to reduce the elongation to approx. 57% (glass fiber) and approx. 39% (carbon fiber).

The diploma thesis is focused on the construction design of elevator for pallets with car seats weighing 200 kg. This device is proposed for vertical transport of the load between two working positions which are separated by 6m. Part of the pallet hoist is a roller conveyor attached on a lifting frame. The roller conveyor allows loading and unloading pallets from the fixed roller conveyors in the lower and upper station. There are the functional calculations of important parts, strength control of traction belt and shaft of driving pulley drum. By FEM (Finite Element Method) is detected stress distribution of the lifting frame. Parts of the annex are the manufacturing drawings of the lifting frame, shaft of driving drum, the driving station and drawing of the whole assembly vertical conveyor. Furthermore, the timing diagram function for one cycle, risk analysis and FMEA.