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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Effiziente Technologien zur Herstellung von endlosfaserverstärkten, schmierungsfreien Antriebs- und Förderketten / Efficient technologies for the production of endless fiber-reinforced and lubrication-free chains for drive or conveying systems

Bankwitz, Hagen 17 January 2018 (has links) (PDF)
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).
72

Die Diskrete Elemente Methode als Simulationsmethode in der Vibrationsfördertechnik

Dallinger, Niels 05 October 2017 (has links) (PDF)
Vibrationsförderer sind Stetigförderer, welche Fördergüter durch periodische Schwingbewegungen in gerichtete Bewegungen versetzen. Vibrationsförderer sind in der Handhabungstechnik, der Zuführung von Mikrobauteilen und feinen Pulvern, sowie in der Schüttgut verarbeitenden Schwerindustrie weit verbreitet. In dieser Arbeit erfolgt nach der Betrachtung des Stands der Technik von Vibrationsförderern und den Interpretationsmöglichkeiten der Förderorganbewegung, die Vorstellung und Diskussion weiterer analytischer Berechnungsansätze. Anschließend werden Störprozesse, die während des Guttransportes auf Vibrationsförderern immer wieder beobachtet werden, erstmals klassifiziert und mathematisch beschrieben. Um die DEM-Simulation von Vibrationswendelförderern und linearen Vibrationsförderern unter Verwendung des Gleit-, Wurf- und Haft-Gleitförderprinzips in der Software LIGGGHTS zu ermöglichen, wurde eine Softwareerweiterung entwickelt. Diese Erweiterung umfasst zwei Module, welche die Bewegungen von importierten CAD-Geometrien auf Basis von als Fourierreihen definierten harmonischen Schwingungen höherer Ordnung ermöglichen. Das Befehlsmodul viblin ermöglicht die Definition von translatorischen Schwingungen. Das Modul vibrot ermöglicht die Definition von Rotationsschwingungen um eine raumfeste Achse. Beide Bewegungsmodule ermöglichen die Definition von komplexen Schwingungszuständen der CAD-Geometrien. Untersuchungen der Mikroprozesse innerhalb einer Arbeitsperiode zeigen, für die Förderarten Wurf und Gleiten, alle notwendigen Abschnitte der Kraft- und Geschwindigkeitsverläufe am Fördergut. Die durchgeführten Validierungen stellen die Verwendung der DEM als Simulationswerkzeug in der Vibrationsfördertechnik sicher. Auf der Basis der abschließend durchgeführten Parameterstudien können in Zukunft Kalibrierungsmethoden bezüglich des Verhaltens von Partikeln auf vibrierenden Unterlagen entwickelt werden. / Vibratory conveyors are continuous conveyors which move the materials to be conveyed by periodic vibrations of the conveyor chute. Vibrating conveyors are used in handling technology, the supply of micro components and fine powders, as well as in bulk material processing heavy industry. Within this work the state of the art of vibratory conveyors and alternative interpretations of the conveyor movement are introduced. Afterwards further analytical approaches are discussed. Subsequently, interfering processes, which occur during the transport of the materials on vibratory conveyors are classified and mathematically described. To simulate vibrating spiral conveyors and linear vibration conveyors using the sliding, throwing or sticking-glide conveyor principle in the software LIGGGHTS, a software extension was developed. This extension includes two software modules, to define the movements of imported CAD geometries on the basis of as Fourier series defined harmonic oscillations. The viblin command module allows the definition of translatory vibrations. The module vibrot allows the definition of rotational vibrations around a fixed axis. Both motion modules allow the definition of complex vibrational states of the CAD geometries. Investigations of the micro processes within a working period showed all necessary sections of the force and speed progression on the conveyed particles for the conveyor principles of micro throw and slide. The validations constitute the basic function of the DEM as a simulation tool in the vibratory conveyor technology. The final parameter studies can be used to develop calibration methods to describe the motion of particles on vibrating plates
73

High-Speed Conveying System / Hochgeschwindigkeits-Fördersystem

Hübler, Jörg, Dallinger, Niels 19 December 2017 (has links) (PDF)
Increasingly higher and higher conveyor speeds are driven in industrial manufacturing. This goes along with a significant rise of the sound pressure level in the production lines. The main cause of this is the articulated and multi-articulated construction of standard plastic-slide-chains in conveyor systems. This condition could be significantly improved by the use of a nonarticulated attraction in the form of a transport toothed belt. In addition, the conveying speeds could be significantly increased. Modifications to the belt teeth provide fastening possibilities for plastic support plates. / Zunehmend werden immer höhere Fördergeschwindigkeiten in industriellen Anlagen gefahren. Dies geht einher mit einer signifikanten Erhöhung des Schalldruckpegels der Anlagen. Die Hauptursache dafür liegt im gliederartigen sowie mehrgelenkigen Aufbau von Standard-Kunststoffgleitketten in Förderanlagen. Dieser Zustand konnte durch die Verwendung eines gliederlosen Zugmittels in Form eines Transportzahnriemens deutlich verbessert sowie die Transportgeschwindigkeiten signifikant erhöht werden. Durch Modifikationen an den Riemen-zähnen werden Befestigungsmöglichkeiten für Kunststofftragplatten geschaffen.
74

Strong winds in extratropical cyclones

Slater, Tim Paul January 2015 (has links)
This thesis was funded by the Natural Environment Research Council (NERC) and is presented in an alternative thesis format. The thesis consists of three separate journal articles which form a coherent research project. Paper 1 investigates the development of strong winds in a dry, idealised extratropical cyclone using the horizontal momentum equation. In particular, the southwest wind maximum that develops was found to contain air parcels from three airstreams. The development of the horizontal along-flow forces around the cyclone and along trajectories entering the southwest wind maximum were analysed. An attempt to extend this methodology to a moist, idealised extratropical cyclone was made. However, the effect of adding moisture to the initial condition was found to be negligible. The reasons for this are explored in Paper 2, which documents this finding: that the effect of moisture on the development of an idealised, baroclinic wave is sensitive to the choice of initial condition. Paper 3 applies the horizontal momentum equation diagnostics to an intense, marine extratropical cyclone that brought strong winds to Ireland and the United Kingdom on 12 February 2014. The development of strong winds in Cyclone Tini was investigated by turning off latent heat release and surface fluxes. In the absence of latent heat release a weaker wind maximum developed. However, the simulation without surface fluxes had a very similar vertical structure of the horizontal wind to the full-physics simulation, but a weaker surface wind maximum. The reason for this weaker wind maximum was analysed using the quasigeostrophic omega equation. This analysis demonstrated a maximum in forcing for descent southwest of the low both in the full-physics simulation and in the simulation without surface fluxes, however strong winds were prevented from reaching the surface in the simulation without surface fluxes because of a more stable boundary layer around the bent-back front.
75

Transportör till portabel käftkross

Nordström, Emil, Forsberg, Marcus January 2018 (has links)
Detta examensarbete är utfört på uppdrag av Cidema AB i Skellefteå och omfattar framtagningen av en teknisk lösning som i dagsläget saknas i företagets sortiment. Uppdragsgivaren har efter kundförfrågningar uppfattat att det finns ett behov av en transportörlösning som tillbehör till den egna produkten, käftkrossen, Danex DX 8. En käftkross är en maskin som används för sönderdelning av hårt och grovt material till en mer lätthanterlig storlek. Modellen DX 8 är en portabel kross som är avsedd att användas vid mindre rivningsprojekt för sönderdelning av bland annat betong, tegel och kakel.  Målet med projektet är att i slutändan erhålla en teknisk lösning som anpassats efter käftkrossens utformning och given kravspecifikation. Resultatet av projektet blev en bandtransportör som i enlighet med kravspecifikationen anpassats till käftkrossen och dess behov av utveckling, för att bättre tillfredsställa kunders önskemål på förbättrad ergonomi och mångsidighet. Transportören har anpassats att fungera både för in-matning och bortforsling av rivningsmaterial, till och från krossen. Detta bidrar till att krossen, med projektets tekniska lösning, kräver mindre fysisk ansträngning vid in-matning av material samt är oberoende av ett vakuumaggregat för bortforsling av material.
76

Konstrukce jednoúčelového stroje pro broušení cihel LI CRETE / Construction of single-purpose machine for grinding bricks LI CRETE

Hubálek, Tomáš January 2017 (has links)
The aim of this thesis is to design a one-purpose machine for grinding concrete light-permeable bricks LiCrete. The bricks LiCrete are a new interior design component. The final step of manufacturing is wet grinding with high quality and accuracy. At the same time it is grinded the concrete and light-permeable parts made by polymethylmethacrylate (PMMA). It is important to keep size and quality appearance of the bricks. The research part contains description of the problems related to the grinding of the bricks LiCrete. The next part is about conceptual variants of the solution. The construction contains the complex solution of one-purpose machine with technical drawings. The last part include a conceptual design of continuous high-productive machine for grinding LiCrete bricks.
77

Konstrukce a programové vybavení transportních entit pro testbed Průmysl 4.0 / Design and implementation of software for transportation entities of the Industry 4.0 testbed.

Sýkora, Tomáš January 2019 (has links)
This diploma thesis deals with construction and software of transport entities for testbed Industry 4.0. The aim of the thesis is to create a transport network for moving a glass with a drink between individual cells on a production table. A four-axis Epson SCARA manipulator is used to transport the glass and a conveyor with carriages is designed to serving the finished drinks. The first part deals with the description of used components and their electrical connections. The second part describes the program solution of robotic manipulator and programmable logic controller. The final part is devoted to the description of problems arising during implementation.
78

Manipulátor balíků / Manipulator of pack

Raba, Milan January 2008 (has links)
This work is about construcion of a manipulator to be used in paper manufacturing. The manipulator is desinged to turn a package of cellulose placed on a roller conveyor. Turning of the package is necessary for unwrapping and cleaness control of cellulose. Design was made based on analytical calculation and was verified using computer simulation. Pneumatic valves and an electric motor were utilized in the manipulator. The manipulator operates automatically.
79

Paletový dopravník / Pallet conveyor

Klembara, Lukáš January 2009 (has links)
This master’s thesis describes the structural design of pallet conveyor for the transport pallet unit between the ground floor and upper storey of warehouse buildings, according to given technical parameters. The work includes design and functional solution for driven roller track. It solves lifting of frame cage and roller track and the pallet unit, using traction gearless drive. There is used cable transfer 2:1. Frame cage is equipped with a mandatory safety gear. The design is verified strength calculations of the frame lift and frame cage. Part of the thesis is the drawing documentation.
80

Navíječ pryžových dopravníkových pásů / Rubber conveyor belt winder

Richtr, Pavel January 2010 (has links)
The point of the diploma thesis is to design the machine for winding of rubber conveyor belts with width 1830 mm to rolls of maximum diameter 4500 mm.

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