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A novel rotary series elastic actuator (RSEA) with a two-mode, or bimodal, elastic element was designed and tested. This device was developed to eliminate the compromise between human safety and robot performance. Rigid actuators can be dangerous to humans within a robot's workspace due to impacts or pinning scenarios. To increase safety, elastic elements can soften impacts and allow for escape should pinning occur. However, adding elasticity increases the complexity of the system, lowers the bandwidth, and can make control of the actuator more difficult. To get the best of both types of actuators, a bimodal clutch was designed to switch between rigid actuation for performance and elastic actuation for human safety. The actuator consisted of two main parts, a rigid rotary actuator using a harmonic gearhead and a drum brake designed to act as a clutch. The 200 W rotary actuator provides 54.7 Nm of torque with a maximum speed of 41.4 rpm. The measured efficiency was 0.797 due to a timing belt speed reduction that was then speed reduced with a harmonic gearhead. The clutch was a drum brake actuated with a pantograph linkage and ACME lead screw. This configuration produced 11 Nm of holding torque experimentally but was theoretically shown to produce up to 51.4 Nm with larger motors. The elastic element was designed using finite element analysis (FEA) and tested experimentally to find a measured stiffness of 290 Nm/rad. / Master of Science

An experimental investigation of noise in a pressure-balanced sliding vane pump was conducted. The test pump for this research was used in an automobile's hydraulic power steering system. As currently designed, a small portion of the manufactured pumps generate excessive noise during operation. An experimental test stand facility was used to represent a power steering system for analysis of the excessive noise problem with the objective of determining ways to reduce the noise. Through signature analysis techniques, the sliding vane pump noise was related to the pump's pressure pulsations. The pulsations consisted of three types of pressure oscillations: the pressure ripple with a fundamental component at the vane passage frequency together with harmonics; the low-frequency pressure oscillation with a fundamental component at the rotational frequency together with harmonics; and the high-frequency pressure oscillation. The fundamental vane passage frequency and its harmonics dominated the noise signal frequency spectrum. The pump's internal leakage, which was a function of three clearances in the pumping chamber, determined the magnitude of the pressure pulsations. If the pumping chamber components had inadequate clearances, the pump produced excessive pressure pulsations for a given discharge pressure and, consequently, excessive fluid-borne noise generation. Thus, this study indicated increasing the pump's clearances would minimize the pump's noise generation. / M.S.

This master’s thesis deals with calibration of incremental encoders. Introduces basic principles and terms in the field of rotary encoders and its calibration. The first part describes angular displacement sensors. Especially it focuses on optoelectrical incremental encoders. It also includes market research of very high-accuracy encoders. The second part contains description of precision calibration techniques with uncertainty to the thousandth of an arc-sec level. In the last part, the development of a calibration stage is presented and consequently the error map of an encoder is obtained.

This thesis, which has been carried out at the department of research and development at Cobham Antenna Systems, comprises the development of a fluid rotary joint (FRJ) prototype and shall provide a thorough insight in relevant design aspects. Based on input parameters and objectives derived from an actual Cobham project, the possibility of manufacturing a fluid rotary joint in-house has been investigated. A rotary joint is sub-system built up by modules linking signal transmission between the stationary and rotating parts of a microwave communication system, typically a rotating radar antenna. High power may generate a need of liquid cooling, i.e. a need of a fluid rotary joint module enabling connection of the up- and downstream of a recirculating cooling system, independent of antenna rotation and with minimal leakage. The typical FRJ features a bearing supported rotor mounted with a number of rotary seals inside a casing, referred to as stator, with channels guiding fluid from one to the other. Key objectives of the design are the flow channel configuration and flow performance relative geometrical size and structural integrity. As a result of the comprehensive pre-study three FRJ concepts were created and evaluated based on a customer requirement specification. The most advantageous design, in terms of e.g. manufacturability and flow performance potential, a multi-channel rotor design with mechanical face seals, was selected for further development. The CAD models were created in Solid Edge ST5, evaluated using FEM-analysis in ANSYS Workbench 14.5 and CFD analysis in ANSYS Fluent. The resulting prototype design features wide internal channels, a generous centre bore clearance equivalent to a diameter of 58 mm, robust mechanical face seals and a sturdy stainless steel stator and rotor design with a total weight below 29.2 kg. With a total pressure loss per channel of less than 0.0065 MPa at the specified mass flow rate of 1.5 kg/s the module are capable of mass flow rates up to 2.5 kg/s until reaching the specified maximum pressure loss of 0.02 MPa. Keywords: Rotary union, Rotary coupling, Flow loss, FRJ, RJ / Detta examensarbete, utfört under avdelningen för forskning och utveckling hos Cobham Antenna Systems, består av utvecklingen av en roterskarvsprototyp avsedd för vätskor och ska tillhandahålla en utförlig inblick kring faktorer relevanta för dess konfiguration. Utifrån ingående konstruktionskriterier och målsättningar, hämtade ur ett befintligt projekt hos Cobham, har möjligheterna för att utveckla och tillverka en fluidskarv inom företaget utretts. En roterskarv är ett delsystem uppbyggt av moduler som länkar signalsändningar mellan de stationära och roterande delarna i ett mikrovågskommunikationssystem, typiskt en roterande radarantenn. Med höga effekter kan behovet av vätskekylning uppstå, det vill säga ett behov av en roterskarvsmodul med kanaler som sammanbinder ett slutet kylsystems upp- och nedflöden oberoende antennrotation och med minimalt läckage. Generellt består en sådan fluidskarv av en lagrad rotor monterad i ett hus, kallad stator, vars interna kanaler sammanbinds genom rotationstätningar. Kanalernas utformning och flödeskapacitet relativt fysisk storlek och strukturell integritet anses vara avgörande. Som resultat av den omfattande förstudien baserat på kundkrav skapades tre fluidskarvskoncept som sedan utvärderades. Konceptet som ansågs mest lämpat för vidareutveckling, utifrån bland annat tillverkningsmöjlighet och flödeskapacitet, består av en flerkanalig rotor primärt tätad av tåliga mekaniska plantätningar. CAD-modeller skapades i Solid Edge ST5, utvärderades med hjälp av FEM-analys i ANSYS Workbench 14.5 och CFD-analys i ANSYS Fluent. Vidareutvecklingen resulterade i en prototyp med vida kanaler, en rymlig centrumöppning motsvarande en diamater på 58 mm, robusta mekaniska plantätningar och en stadig design tillverkad i rostfritt stål med en totalvikt under 29.2 kg. Med en tryckförlust på 0.0065 MPa per kanal vid det specificerade massflödet 1.5 kg/s klarar fluidskarven massflöden upp till 2.5 kg/s tills det att den angivna maximala tryckförlusten på 0.02 MPa uppnås. Nyckelord: Vätskeroterskarv, Vätskeroterstycke, Svivel, Roterstycke, Tryckförlust

Diploma thesis deals with a topic of lubrication and cooling of the ball screw rotary nuts. The first part is focused on a research behind the theory of ball screws and ball screw rotary-nuts. The three types of construction were developed in the second half of the thesis. Each construction is designed as an external attachable cooling and lubrication unit, which can be installed on an existing, slightly modified ball screw rotary-nut. For cooling and lubrication, only one type of medium is used and that is a cooled oil. External unit provides medium flow to ball screws working space. On top of diploma thesis tasks a design concept of ball screw rotary-nut with an integrated cooling and lubrication is introduced itself. Both described designs could become interesting for an industrial market.

Hybrid electric vehicles significantly reduce exhaust emissions and increase fuel economy. Power packs are the most fundamental components in a series powertrain configuration of a hybrid vehicle, which produce the necessary power to run the vehicle. The aim of this project is to design a compact power pack for a series hybrid vehicle, using virtual prototyping. The hybrid electric vehicle characteristics and configurations are analysed, followed by an explanation of the principles of induction machines. A new type of rotary induction machine with an outer rotor construction is designed to be coupled with the novel rotary internal combustion engine with rotating crankcase in order to form the compact power unit for the hybrid vehicle. The starting and generation performance of the designed machine is analysed by an electric machine simulator, called JMAG. ADVISOR software is studied and utilised to simulate the overall vehicle performance, employing different categories of power packs in the powertrain. Results show that the proposed compact power pack has the best performance in terms of fuel economy, emissions and battery charging compared to the existing power unit options. Over the city cycle, fuel economy is increased by up to 47 % with emission reduced by up to 36 % and over the highway cycle, fuel economy is increased by up to 69 % with emission reduced by up to 42 %.

No preparo dos canais radiculares, eminentemente os curvos, a abordagem cérvico-apical amplamente difundida promovendo a dilatação da região cervical do canal radicular previamente à atuação de instrumentos em sua região apical constitui técnica e inegavelmente uma forma adequada, tanto do ponto de vista mecânico como microbiológico, de interagir com o espaço endodôntico em busca de uma experiência bem sucedida e previsível. De outra forma, os mais recentes instrumentos endodônticos, muito mais flexíveis em decorrência das novas ligas de baixo módulo de elasticidade empregadas em sua fabricação e dotados de novos índices de conicidade, surgem melhorando tais perspectivas. Desde o surgimento da liga de Níquel-Titânio na Endodontia, na década de oitenta, uma gama imensa de instrumentos desta derivados e para serem empregados com dispositivos mecânicos, eletromecânicos ou pneumocânicos, têm reavivado a esperança de se obter um dispositivo ideal que simulando a cinemática manual supere as limitações operacionais decorrentes, principalmente, da configuração anatômica do canal radicular. Assim, neste experimento verificou-se o desempenho de quatro diferentes recursos técnicos no desgaste da região cervical do canal radicular. Constituíram-se quatro amostras, cada qual composta de 10 espécimes (raízes mésio-vestibulares de primeiros molares superiores), para serem preparadas com (i) Brocas Gates-Glidden, (ii) Brocas Largo-Peeso, (iii) ProFile® .04/.06 & Orifice Shapers e (iv) Pow-R Coronal Shapers. Imagens digitais obtidas antes e após o preparo do canal radicular foram analisadas também digitalmente estudo morfométrico computadorizado avaliando-se a variação das áreas das mesmas em função do desgaste promovido pelos referidos instrumentos. Todos os instrumentos produziram desgaste de ambas as paredes, mesial e distal, do canal radicular na região analisada. A análise estatística das variações de área para o fator parede mesial não mostrou diferenças estatisticamente significantes entre os grupos experimentais para =5%. No entanto quando da comparação dos grupos experimentais para o fator parede distal verificou-se diferenças estatisticamente significantes entre os grupos #1 e #3 para =5%. Ainda, para o fator área total (paredes mesial e distal) verificou-se diferenças estatisticamente signifcantes entre os grupos #3 e #4 para =5%. Concluiu-se que todos os instrumentos testados produzem desgaste tanto da parede mesial como da parede distal do canal radicular e, conseqüentemente, da estrutura dentinária global da região cervical do canal radicular. Por outro lado verificou-se uma tendência da Broca Gates-Glidden em promover maior desgaste da parede distal que o Sistema ProFile® .04/.06 & Orifice Shapers e do Sistema Pow-R Coronal Shapers em promover maior desgaste da estrutura toal que o Sistema ProFile® .04/.06 & Orifice Shapers. / Nowadays is common sense among endodontists that in root canal preparation, mainly the curved ones, the crown-down approach enlarging the cervical third prior instrumentation of the apical third regions provides better interaction between the instrument and the canal walls than the conventional methods. Technically it provides an adequate form to achieve the best and predictable results in cleaning and shaping the root canal system. Additionally the most recent nickel-titanium made endodontic instruments more flexible than the stainless steel instruments and the new taper design have been appeared to improve the endodontic panorama. Since the introduction of the nickel-titanium alloy in Endodontics by Walia et al. in 1988 a number of instruments produced by such alloy in conjunction with the engines new generation have brought new perspectives to deal tridimensionally with the still challenger endodontic space. In this study the performance of four different instruments in the root canal cervical third enlargement was evaluated. Four experimental groups comprised by ten upper molars mesiobuccal roots each were prepared by either (i) Gates bur, (ii) Largo bur, (iii) Profile® .04/.06 & Orifice Shapers or (iv) Pow-R Coronal Shapers. Before and after preparation digitally acquired images were evaluated for area changes within both mesial and distal root canal walls. All instruments produced some amount of wear in both walls and the distals have changed more than the mesials in most times probably due an excentric performance of all evaluated instruments. Comparison of root canal walls wearing among the four experimental groups showed no statistically significant differences (=5%) for mesial wall. However, statistically analyze (=5%) showed significant differences between Experimental Group #1 (Gates-Glidden burs) and Experimental Group #3 (Profile® .04/.06 & Orifice Shapers) for distal walls with the first showing greater wearing than the latter. Also, the results showed statistically significant differences between Experimental Group #4 (Pow-R & Coronal Shapers) and Experimental Group #3 (Profile® & Orifice Shapers) for the entire structure i.e. mesial and distal walls with the first showing the greater than the latter wearing . It was concluded that all tested instruments wear so the mesial as the distal root canal walls. Experimental results have showed that in first upper molaras mesiobuccal roots Gates-Glidden bur for distals and Pow-R nickel-titanium instruments for both walls, i.e. the cervical dentin entire structure, are supposed to wear more root canal cervical third dentin than the others instruments which they were compared.

Made available in DSpace on 2016-12-23T14:32:59Z (GMT). No. of bitstreams: 1 Consideracoes Finais.pdf: 12626 bytes, checksum: 4ff9fc99c6d66dfba678102aa8698f0d (MD5) Previous issue date: 2007-07-27 / In this research, the spotlights are aimed on the historical years between 1959 and 1967, with the main purpose of showing the scenic arrangements of the installation, organization and performance of a Rotary Club in a geographical scenery that was in mutation phase. That territory, formerly denominated Promised Earth or Canaan of the Industry, was soon substituted by the nomenclature Steel Valley .The partners founders of that first Rotary Club conceived themselves as foreigners from the Canaan of the State of Minas that emanated "milk and honey". Native from another lands, they met each other and they were met in order to form a service club in the Nacional Valley of Redemption, but with intense institutional entails to an international corporation. Organized under the doctrine of the interest well understood, the associated agents, each one, with his composition and capital volume, of economic, cultural, social, symbolic or political nature, they allowed, through the mechanism of capital convertibility, to concentrate, in the regional community, a power, capable to produce real effects without apparent waste of energy. As a voluntary and oligarchical association, this service club was, in a way, a institutional vehicle, in the local sphere, of appropriation, incorporation, reproduction and diffusion of visions of world of the ideological corpus of International Rotary. / Nesta pesquisa, os holofotes estão apontados sobre os anos históricos, compreendidos entre 1959 e 1967, com a finalidade última de mostrar os arranjos cênicos da instalação, organização e atuação de um Rotary Club num cenário geográfico que se encontrava em fase de mutação. Esse território, outrora denominado Terra Prometida ou Canaã da Indústria, foi logo substituído pela nomenclatura Vale do Aço. Os Sócios fundadores desse primeiro Rotary Club conceberam-se como forasteiros da Canaã do Estado de Minas que emanava leite e mel . Originários de outras terras, encontraram-se e foram encontrados para formarem um clube de serviço no Vale da Redenção Nacional, mas com fortes vínculos institucionais a uma corporação internacional. Organizados sob a doutrina do interesse bem compreendido, os agentes associados, cada qual, com sua composição e volume de capital, sejam eles de natureza econômica, cultural, social, simbólico e/ou político, que permitiu, através do mecanismo de convertibilidade de capital, potencializar, na comunidade regional, um poder capaz de produzir efeitos reais sem dispêndio aparente de energia. Como uma associação voluntária e oligárquica, esse clube de serviço foi, em alguma medida, um veículo institucional, na esfera local, de apropriação, incorporação, reprodução e difusão de visões de mundo do corpus ideológico do Rotary Internacional.

No preparo dos canais radiculares, eminentemente os curvos, a abordagem cérvico-apical amplamente difundida promovendo a dilatação da região cervical do canal radicular previamente à atuação de instrumentos em sua região apical constitui técnica e inegavelmente uma forma adequada, tanto do ponto de vista mecânico como microbiológico, de interagir com o espaço endodôntico em busca de uma experiência bem sucedida e previsível. De outra forma, os mais recentes instrumentos endodônticos, muito mais flexíveis em decorrência das novas ligas de baixo módulo de elasticidade empregadas em sua fabricação e dotados de novos índices de conicidade, surgem melhorando tais perspectivas. Desde o surgimento da liga de Níquel-Titânio na Endodontia, na década de oitenta, uma gama imensa de instrumentos desta derivados e para serem empregados com dispositivos mecânicos, eletromecânicos ou pneumocânicos, têm reavivado a esperança de se obter um dispositivo ideal que simulando a cinemática manual supere as limitações operacionais decorrentes, principalmente, da configuração anatômica do canal radicular. Assim, neste experimento verificou-se o desempenho de quatro diferentes recursos técnicos no desgaste da região cervical do canal radicular. Constituíram-se quatro amostras, cada qual composta de 10 espécimes (raízes mésio-vestibulares de primeiros molares superiores), para serem preparadas com (i) Brocas Gates-Glidden, (ii) Brocas Largo-Peeso, (iii) ProFile® .04/.06 & Orifice Shapers e (iv) Pow-R Coronal Shapers. Imagens digitais obtidas antes e após o preparo do canal radicular foram analisadas também digitalmente estudo morfométrico computadorizado avaliando-se a variação das áreas das mesmas em função do desgaste promovido pelos referidos instrumentos. Todos os instrumentos produziram desgaste de ambas as paredes, mesial e distal, do canal radicular na região analisada. A análise estatística das variações de área para o fator parede mesial não mostrou diferenças estatisticamente significantes entre os grupos experimentais para =5%. No entanto quando da comparação dos grupos experimentais para o fator parede distal verificou-se diferenças estatisticamente significantes entre os grupos #1 e #3 para =5%. Ainda, para o fator área total (paredes mesial e distal) verificou-se diferenças estatisticamente signifcantes entre os grupos #3 e #4 para =5%. Concluiu-se que todos os instrumentos testados produzem desgaste tanto da parede mesial como da parede distal do canal radicular e, conseqüentemente, da estrutura dentinária global da região cervical do canal radicular. Por outro lado verificou-se uma tendência da Broca Gates-Glidden em promover maior desgaste da parede distal que o Sistema ProFile® .04/.06 & Orifice Shapers e do Sistema Pow-R Coronal Shapers em promover maior desgaste da estrutura toal que o Sistema ProFile® .04/.06 & Orifice Shapers. / Nowadays is common sense among endodontists that in root canal preparation, mainly the curved ones, the crown-down approach enlarging the cervical third prior instrumentation of the apical third regions provides better interaction between the instrument and the canal walls than the conventional methods. Technically it provides an adequate form to achieve the best and predictable results in cleaning and shaping the root canal system. Additionally the most recent nickel-titanium made endodontic instruments more flexible than the stainless steel instruments and the new taper design have been appeared to improve the endodontic panorama. Since the introduction of the nickel-titanium alloy in Endodontics by Walia et al. in 1988 a number of instruments produced by such alloy in conjunction with the engines new generation have brought new perspectives to deal tridimensionally with the still challenger endodontic space. In this study the performance of four different instruments in the root canal cervical third enlargement was evaluated. Four experimental groups comprised by ten upper molars mesiobuccal roots each were prepared by either (i) Gates bur, (ii) Largo bur, (iii) Profile® .04/.06 & Orifice Shapers or (iv) Pow-R Coronal Shapers. Before and after preparation digitally acquired images were evaluated for area changes within both mesial and distal root canal walls. All instruments produced some amount of wear in both walls and the distals have changed more than the mesials in most times probably due an excentric performance of all evaluated instruments. Comparison of root canal walls wearing among the four experimental groups showed no statistically significant differences (=5%) for mesial wall. However, statistically analyze (=5%) showed significant differences between Experimental Group #1 (Gates-Glidden burs) and Experimental Group #3 (Profile® .04/.06 & Orifice Shapers) for distal walls with the first showing greater wearing than the latter. Also, the results showed statistically significant differences between Experimental Group #4 (Pow-R & Coronal Shapers) and Experimental Group #3 (Profile® & Orifice Shapers) for the entire structure i.e. mesial and distal walls with the first showing the greater than the latter wearing . It was concluded that all tested instruments wear so the mesial as the distal root canal walls. Experimental results have showed that in first upper molaras mesiobuccal roots Gates-Glidden bur for distals and Pow-R nickel-titanium instruments for both walls, i.e. the cervical dentin entire structure, are supposed to wear more root canal cervical third dentin than the others instruments which they were compared.