No description available.

This master´s thesis deals with design of small CNC milling machines and comparing CNC tabletop milling machines in the world market. It is also done design of small CNC milling machine through the use of contemporary and modern trends, used in design of machine tools.

Although the design principles of the Switched Reluctance Machines (SRMs) are available in different fragments in numerous bibliography positions, there no exists the complex design procedure of whole drive system taking into account the SR Machine, control system and supply device as well. The hybrid design method for SRM drives with application of new analytical calculation methods, finite element method and simulation models is proposed in this thesis. The calculation/design system is characterised by important effectivity and reliability. The new possibilities in analytical determination of saturation effects and core losses under various modes of control, including sensorless method, are also taken into account. The correctness of the proposed design algorithms are verified by laboratory tests made on three motor prototypes manufactured in industry for concrete application. This dissertation provides the elements indispensable for more accurate and complex analysis and design of drives with switch reluctance motors. The elements of electrical motor and control system design as well as the considerations on the choice of supply device and controller subsystems are jointed in the thesis for final receiving of the design tool for considered industrial drive system.

Denna rapport ar resultatet av ett kandidatexamensarbete som avlades på KTH under våren 2018 i maskinkonstruktion. Uppdragsgivare var KTH och Skogforsk; det svenska skogsbrukets forskningsinstitut, som är finansierat av skogsnäringen och den svenska staten. Bakgrunden till projektet är de ökande kraven på ekologi och ergonomi i branchen, samt bristen på förare och operatörer. Uppgiften var att förbereda en skotare, modellXt28, för automation modellbaserat. En skotare är ett terrängfordon som används för att transportera rundvirke, stubbar och liknande. Då arbetet för att helt automatisera ett fordon är väldigt omfattande begränsades detta projekt till att fokusera på skotarens perception av omgivningen. Läsaren kommer få ta del av utformningen av en skyddande sensorenhet, anpassad för den krävande miljön. Krav för automation av fordon, val av sensorer och placering av dessa, möjliga lastfall, och infästningsmöjligheter behandlas. En utmaning under arbetets gång har varit bristen på tillgängligt tidigare liknande arbete, där kombinationen autonomi och helt odefinierat körområde behandlades. / This report is the result of a bachelor thesis completed at KTH (Royal Institute of Technology, Stockholm, Sweden) during spring 2018 in machine design. The project was executed in collaboration with KTH and Skogforsk (the Forestry Research Institute of Sweden), which is the central research body for the Swedish forestry sector, and financed jointly by the government and the members of the institute. The background of the project is the ever increasing requirements of ecology and ergonomics in the business, and the shortage of operators. The object of the project was to prepare and adapt a forwarder developed by Skogforsk (among others), Xt28, for automation. A forwarder is a forestry vehicle used for transporting logs. As the process of fully automating a vehicle is very extensive this project was limited to focusing on the forwarder's perception of the surrounding environment. The reader will take part in the development of a protective sensor unit, fitted for the demanding environment of a forwarder in Sweden. Requirements for vehicle automation, suitable sensors and placement, possible load cases, and attachment possibilities will be considered. A challenge during the project was the lack of earlier work and projects found on the same area, where self driven vehicles and operation o road were both regarded.

This thesis presents an investigation of the modelling and optimal design of a particular 3-degree-of-freedom (DOF) XYθz micro-motion stage. This stage provides micron-scale motion in X and Y directions and a rotation about the Z-axis. Such a stage can be used for applications where positioning of components with micrometre, or even nanometre positioning accuracy is required. Some applications are; the positioning of samples in a scanning-electron-microscope; the positioning of masks in lithography; aligning fibre-optics and lasers; and manipulation of micro-scale objects in micro-biology or micro-systems assembly. The XYθz micro-motion stage investigated in this study uses a particular topology of monolithic compliant mechanism and three stack piezoelectric actuators. The compliant mechanism used is a 3RRR (three revolute-revolute-revolute) parallel compliant mechanism using flexure hinges. This parallel mechanism uses three RRR linkages. Each of the three RRR linkages uses three circular profile flexure hinges. Each flexure hinge provides predominantly rotational motion about one axis. This topology of mechanism has a symmetrical structure and provides numerous advantages that make it appropriate for use in a micro-motion stage. However, as yet this topology of compliant mechanism has only been investigated by a handful of researchers and it has not been used in any commercially developed systems. The design methodology of a stage using the 3RRR compliant mechanism has not been investigated in detail. In this thesis a study is presented that investigates different approaches to model the 3RRR compliant mechanism and also considers the piezo-actuator modelling, to give the complete XYθz micro-motion stage. Three models are presented and compared; the Pseudo-Rigid-Body Model (PRBM); a two-dimensional Finite-Element-Model (2-D FEM); and a third model is developed that is similar to the PRBM, but uses analytical equations to model the multiple degree-of-freedom compliance of the flexure hinges. The models developed are then used in parametric study so that the relationship between design parameters and output behaviour can be understood. An optimal design approach is then presented to develop an XYθz micro-motion stage for a particular application in a Scanning-Electron-Microscope (SEM). Finally experimental validation of the models is presented. The results of this study indicate which modelling approaches are accurate enough to prove useful for design, while also considering which models are computationally simple enough to be efficient and easy to use. The kinematic and dynamic behaviour of the 3RRR compliant mechanism and XYθz micro-motion stage is discussed in detail. This includes; a comprehensive description of the stage workspace, defining reachable and constant-rotation workspace areas; a discussion of actuator coupling; and in depth investigation of the modes of vibration. The results of the parametric study provide useful insight to aid the design of the XYz micro-motion stage and help simplify optimal design. The parametric study also highlights the difference in trends predicted by different modelling methods, which demonstrates the importance of using an appropriate model in design. The experimental validation demonstrates the accuracy of some modelling approaches while highlighting the limited accuracy of others. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1272186 / Thesis (Ph.D.) -- University of Adelaide, School of Mechanical Engineering, 2007

This thesis presents an investigation of the modelling and optimal design of a particular 3-degree-of-freedom (DOF) XYθz micro-motion stage. This stage provides micron-scale motion in X and Y directions and a rotation about the Z-axis. Such a stage can be used for applications where positioning of components with micrometre, or even nanometre positioning accuracy is required. Some applications are; the positioning of samples in a scanning-electron-microscope; the positioning of masks in lithography; aligning fibre-optics and lasers; and manipulation of micro-scale objects in micro-biology or micro-systems assembly. The XYθz micro-motion stage investigated in this study uses a particular topology of monolithic compliant mechanism and three stack piezoelectric actuators. The compliant mechanism used is a 3RRR (three revolute-revolute-revolute) parallel compliant mechanism using flexure hinges. This parallel mechanism uses three RRR linkages. Each of the three RRR linkages uses three circular profile flexure hinges. Each flexure hinge provides predominantly rotational motion about one axis. This topology of mechanism has a symmetrical structure and provides numerous advantages that make it appropriate for use in a micro-motion stage. However, as yet this topology of compliant mechanism has only been investigated by a handful of researchers and it has not been used in any commercially developed systems. The design methodology of a stage using the 3RRR compliant mechanism has not been investigated in detail. In this thesis a study is presented that investigates different approaches to model the 3RRR compliant mechanism and also considers the piezo-actuator modelling, to give the complete XYθz micro-motion stage. Three models are presented and compared; the Pseudo-Rigid-Body Model (PRBM); a two-dimensional Finite-Element-Model (2-D FEM); and a third model is developed that is similar to the PRBM, but uses analytical equations to model the multiple degree-of-freedom compliance of the flexure hinges. The models developed are then used in parametric study so that the relationship between design parameters and output behaviour can be understood. An optimal design approach is then presented to develop an XYθz micro-motion stage for a particular application in a Scanning-Electron-Microscope (SEM). Finally experimental validation of the models is presented. The results of this study indicate which modelling approaches are accurate enough to prove useful for design, while also considering which models are computationally simple enough to be efficient and easy to use. The kinematic and dynamic behaviour of the 3RRR compliant mechanism and XYθz micro-motion stage is discussed in detail. This includes; a comprehensive description of the stage workspace, defining reachable and constant-rotation workspace areas; a discussion of actuator coupling; and in depth investigation of the modes of vibration. The results of the parametric study provide useful insight to aid the design of the XYz micro-motion stage and help simplify optimal design. The parametric study also highlights the difference in trends predicted by different modelling methods, which demonstrates the importance of using an appropriate model in design. The experimental validation demonstrates the accuracy of some modelling approaches while highlighting the limited accuracy of others. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1272186 / Thesis (Ph.D.) -- University of Adelaide, School of Mechanical Engineering, 2007

Cette thèse propose une nouvelle structure de machine à courant continu pouvant être utilisée dans une application démarreur Stop-Start automobile. Une structure tridimensionnelle à griffes est proposée pour remplacer le stator à plots actuel dans le but de réduire son coût de fabrication. La structure de la machine à griffes est modélisée par un réseau de réluctances permettant la prise en compte de la saturation et de la réaction magnétique d'induit. Grâce à sa rapidité et précision, ce modèle est ensuite intégré dans un processus d’optimisation afin d'obtenir rapidement une machine optimale. Enfin, un prototype de machine à courant continu à griffes est réalisé, montrant ainsi la faisabilité de cette topologie. Par ailleurs, un modèle original combinant réseaux de réluctances et résolution de l'équation de Laplace a été développé pour lever certaines difficultés liées à la modélisation par réseau de réluctances des machines électriques tout en prenant en compte la rotation / This thesis deals with a new DC machine structure that can be used in an automotive Stop-Start starter application. A three-dimensional claw pole stator is proposed to replace the current stator in order to reduce its manufacturing cost. The claw pole machine topology is modeled by a reluctance network to take into account the saturation and the magnetic armature reaction. Thanks to its speed and precision, this model is then integrated in an optimization process to obtain an optimal machine. Finally, a prototype of a machine with DC claws is manufactured to show the feasibility of this topology. Moreover, an original model combining reluctance networks and solving the Laplace equation has been developed to overtake some difficulties related to modeling by reluctance network of electrical machines while taking into account the rotation

This thesis shows making of documentation for production powerfull wood-splitting machine for hardest forestal work. There are researched and soluted all phases of pre-production machine's lifecycle, also means analysis of conception, potentional risks and failures analysis and also definition of required properties. Based on those properties and results of analyses is possible to setting up condition which should be satisfied. At following part are descripted and shown features of machine-design . Main feature (component) of machine is its frame, also there are strenght analysis of frame. Machine movement features are mainly hydraulics pistons which are powered by asynchronous engine, whith alternative possibility movement by wheel tractor power-take off shaft or hydraulics output. There are performed all important properties. Working safety questions and high endurability of machine shold be also performed. At the end of work is realised conception and design study of forestal production system for wood processing with one universal source of energy – wheeled tractor.

The Swedish Defence Materiel Administration, FMV’s, test site in Vidsel, Norrbotten, has access to the largest area for testing and evaluating military aircraft, missiles and unmanned vehicles over land in Europe. The facility has the capacity to create many different types of test enviroments, which are continously developed to meet the customers growing requirements where the main focus is using different types of aerial targets. This project is a thesis for a Master in Mechanical Engineering and Machine Design. The purpose of the project was to develop a new brake system for the aerial tow target, SM3C. The goal of the project was to come up with a concept with enough support to say what, why and how the new concept meets the desired requirements. With a structured and iterative product development process, based on Ulrich & Eppingers theories, the identified needs of the new brake system and data from the existing product resulted in a product specification with quantifiable metrics. From the development process and product specification, the project resulted in a detailed and designed concept that was more standardized, modular and less complex than the existing product with support from theoretical analysis, experiments and simulations of the brake system. / Försvarets Materialverk, FMVs, provplats i Vidsel, Norrbotten, har tillgång till Europas största provområde för test och evaluering av stridsflygplan, robotar och obemannade farkoster över land. Provplatsen kan presentera en mängd olika testmiljöer som kontinuerligt utvecklas för att möta kundernas växande krav där fokus ligger på olika typer av luftmål. Projektet innefattar ett examensarbete för en civilingenjörsutbildning i maskinteknik med syfte att utveckla ett nytt bromssystem till det luftburna släpmålet, SM3C. Målet med projektet var att tillsammans med en funktionsanalys av det befintliga bromsystemet komma fram till ett koncept med tillräckligt underlag som kunde påvisa vad, varför och hur konceptet uppfyller de önskade kraven. Med en strukturerad och iterativ produktutvecklingsprocess, baserad på Ulrich & Eppingers teorier, bearbetades behoven av ett nytt bromssystem tillsammans med analysen av den befintliga produkten vilket gav en kravspecifikation med kvantifierbar data. Utifrån kravspecifikationen och utvecklingsprocessen, resulterade projektet i ett detaljkonstruerat koncept som var mer standardiserat, modulärt och mindre komplext än befintligt system med stöd från utförda analyser, experiment och simuleringar.

Detta arbete kommer att fokusera på att ta fram och utforma en monterbar behållare för drönare så att de ska kunna användas för att leverera matvaror snabbt vid behov och med hänsyn till befintliga drönares kapacitet. I framtagningsprocessen så kommer de karaktäristiska punkterna för en strukturerad och faktabaserad utformning av en produkt att tillämpas vilket innefattar en identifiering av mål utifrån ett behov som produkten ska uppfylla och en faktainsamling av behovets karaktär och befintliga tekniska lösningar på liknande problem. Med den informationen som underlag så kan senare grundläggande konceptskisser utformas vilka i sin tur kan förädlas till färdiga 3D ritningar och renderingar av en slutgiltig produkt. För att ganska produktens effektivitet i förhållande till ändamålet så används därefter simuleringsverktyg för att genomföra termiska och luftflödesanalyser. Slutligen diskuteras även passande tillverkningsmetoder och produktens hållbarhet, potentiella problem med hela leveransmetoden, förslag till djupare studier och en utvärdering av framtagningsprocessens genomförande. / Technical advancements in fields like battery technology, software engineering and remote-control technology has made commercial unmanned aerial vehicles (UAVs) or “drones” cheaper while also allowing for longer flight times, higher payload capacities and longer effective ranges. This combined with the growing market trend of home delivery services within the restaurant and food industries paves the way for studies on how this relatively new means of transportation can be used to deliver food to customers within range. This paper will focus on developing and designing a third party mountable container from a mechanical engineering perspective that will allow commercially available quadcopter drones to deliver food items from one point to another. This means that the design process will be dictated by a set of identified core needs that the container is meant to satisfy while results from relevant calculations such as load simulations are taken into account. Further information and discussion like proposed manufacturing methods, sustainability and the prospects of further studies will also be brought up as it pertains to the containers design process.