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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.
231

Pojezdový mechanismus mostového jeřábu / The bridge crane's travel mechanism

Žid, Miroslav January 2018 (has links)
The aim of this master thesis is to design replacing the central drive of the overhead crane with dislocated drives. It´s a tong crane with the lifting capacity of 63 tons, located inside the hall. In the thesis is processed functional calculation of two types of drives, the associated types of brakes and the coupling element. Next there is a strength control of a new mechanism seat and a selected components. This whole leads to the output, which is the drawing documentation.
232

Studie příčného rychlostního pole v blízkosti rotujícího kola s uvažováním vlivu nucené konvekce kotoučové brzdy / Study of transverse velocity field in the vicinity of rotating wheel with assumption of forced convection of disc brake

Regner, Dominik January 2019 (has links)
The master thesis deals with the influence of a local change of temperature due to advection from disc brake to axial velocity field close to the rotating wheel of a car. The second goal is to set parameters applicable to various wheel discs and study of the influence of these parameters to aerodynamical properties of car and thermodynamical properties of the disc brake. The thesis is numerically executed in StarCCM+. The first part focuses on theoretical background about the numerical solution and current status of research. There are described disc parameters, geometry input and solver settings in the second part. The final part deals with a comparison of velocity fields for isothermal and thermodynamical model and evaluates the influence of parameters to velocity field, aerodynamical drag and thermodynamical performance of the brake.
233

Experimentelle Untersuchungen von Flüssigmetallströmungen beim Stranggießen von Stahl unter Magnetfeldeinfluss

Schurmann, Dennis 08 November 2021 (has links)
Stahl wird heutzutage fast ausschließlich im kontinuierlichen Stranggussprozess zu Halbzeugen verschiedener Geometrien verarbeitet. Flüssiger Stahl wird dabei über ein Tauchrohr in eine wassergekühlte, nach unten offene Kokille gefüllt und erstarrt an deren Wänden. Der innen noch flüssige Strang wird kontinuierlich nach unten aus der Kokille abgezogen und ist erst nach mehreren Metern komplett erstarrt. Die Qualität des Halbzeugs wird vorwiegend durch die Strömung in der Kokille beeinflusst. In der Industrie werden seit langer Zeit verschiedene elektromagnetische Aktuatoren eingesetzt, um die Strömungsstruktur in der Kokille mithilfe von Lorentzkräften zu beeinflussen. Bedingt durch die hohe Temperatur des flüssigen Stahls und dessen Undurchsichtigkeit lässt sich die Strömungsstruktur im realen Prozess jedoch kaum untersuchen. Zur Optimierung sowie zum besseren Verständnis der Vorgänge in der Kokille sind daher numerische Simulationen und Modellexperimente notwendig. In dieser Arbeit werden die Ergebnisse experimenteller Untersuchungen zum kontinuierlichen Stranggießen von Stahl unter dem Einfluss verschiedener elektromagnetischer Aktuatoren präsentiert. Die Experimente wurden an der Mini-LIMMCAST-Anlage des Helmholtz-Zentrum Dresden-Rossendorf (HZDR) durchgeführt. Mini-LIMMCAST ist ein Modell einer Strangguss-Anlage, welches isotherm mit der bei Raumtemperatur flüssigen Metalllegierung GaInSn betrieben wird. Durch die Verwendung von flüssigem Metall als Modellfluid können die Auswirkungen elektromagnetischer Aktuatoren untersucht werden, jedoch kann aufgrund der Undurchsichtigkeit des Modellfluids die Geschwindigkeitsverteilung in der Kokille nicht mittels optischer Verfahren erfasst werden. Daher wird zur Messung der Geschwindigkeitsverteilung in der Kokille die Ultraschall-Doppler-Velocimetrie eingesetzt. Die Ergebnisse von Messungen an zwei verschiedenen Kokillen-Geometrien werden vorgestellt: zum Einen solche an einer zylindrischen Kokille, bei welcher auf verschiedene Arten eine Drehströmung erzeugt wurde. Dies erfolgte durch elektromagnetisches Rühren in der Kokille sowie durch ein Tauchrohr mit spiralförmigen Auslässen. Zum Anderen wird eine Kokille mit rechteckigem Querschnitt, wie sie in Brammen-Anlagen verwendet wird, betrachtet. In dieser wird die Strömung sowohl durch ein statisches Magnetfeld, einer sogenannten elektromagnetischen Bremse, als auch durch elektromagnetische Wechselfelder beeinflusst. Die Ergebnisse dieser Arbeit zeigen eine Reihe zuvor nicht beschriebener Phänomene, wie das zeitliche Verhalten des Jets in der Rundkokille mit elektromagnetischem Rührer oder den Mechanismus der in der Brammen-Geometrie mit elektromagnetischer Bremse für eine Veränderung der Geschwindigkeit an der freien Oberfläche der Kokille sorgt. Umfassende experimentelle Parameterstudien erlauben detaillierte Einblicke in die beim Stranggießen auftretenden Strömungsstrukturen, wie sie mit numerischen Simulationsmodellen nur unter einem immensen Einsatz von Rechenleistung zu erzielen wären. / Today, steel is almost exclusively processed into semi-finished products of various geometries by the continuous casting process. Liquid steel is filled through a submerged entry nozzle into a water-cooled, downwardly open mould and solidifies on its walls. The strand, which is still liquid on the inside, is continuously drawn downwards out of the mould and is then completely solidified after several metres. The quality of the semi-finished product is mainly influenced by the flow in the mould. For many years, various electromagnetic actuators have been used in industry to influence the flow structure in the mould by the application of Lorentz forces. Due to the high temperature of the liquid steel and its opacity, however, the flow structure can hardly be investigated in the real process. Therefore, numerical simulations and model experiments are necessary to optimise and better understand the processes in the mould. In this dissertation the results of experimental investigations on continuous casting of steel under the influence of different electromagnetic actuators are presented. The experiments were performed at the Mini-LIMMCAST facility of the Helmholtz-Zentrum Dresden-Rossendorf (HZDR). Mini-LIMMCAST is a model of a continuous casting machine which is operated isothermally with the metal alloy GaInSn, which is liquid at room temperature. By using liquid metal as model fluid, the effects of electromagnetic actuators can be investigated, but due to the opacity of the model fluid, the velocity distribution in the mould cannot be determined by optical methods. Therefore, ultrasonic Doppler velocimetry is used to measure the velocity distribution in the mould. The results of measurements using two different mould geometries are presented. One is a cylindrical mould in which a rotational flow was generated in different ways. This was achieved by electromagnetic stirring in the mould and by an submerged entry nozzle with spiral-shaped outlets. On the other hand, a mould with a rectangular cross-section, as used for slab casting, is considered. Here the flow is influenced by a static magnetic field, a so-called electromagnetic brake, as well as by alternating electromagnetic fields. The results of this work show a number of previously undescribed phenomena, such as the temporal behaviour of the jet in the round mould with an electromagnetic stirrer or the mechanism that causes a change in the speed at the free surface of the mould in the slab geometry with an electromagnetic brake. Comprehensive experimental parameter studies allow detailed insights into the flow structures occurring during continuous casting, which could only be achieved with numerical simulation models with an immense input of computing power.
234

Návrh technologie objemového tváření součásti jízdního kola za studena / Design of bulk cold forming technology for bicycle part

Kubíček, Lubomír January 2008 (has links)
The diploma thesis is dealt with a project of a new manufacture method of a bicycle´s part. The part is a brake drum, which is the necessary part of a free-running charge. In an intro-duction of the diploma thesis is described a nowdays manufacture technology and its deficiencies. According to the nowdays manufacture technology was designed a new one, which is based on a cold volumetric shanking. The shanked hemihedron is consequently shaped according to the current technology. After the operation of cold shaping an instrument is projected. The project of the shaping technology is filled up by the calculation of the essential parameters, including an arrangement of the instrument and the process. An economical evaluation of the new process of the brake drum is stated and its advantages and disadvantaged were selected.
235

Navíjecí stroj / Filament Winding Machine

Dorňák, Michal January 2009 (has links)
The aim of this diploma thesis is the proposal of solution of three-axial winding machine for winding technology of rotary profile. Winding materials are continual springs of carbon, aramid or glass fibre impregnated by resin. The main construction change of the machine compared to commercial available solutions is the use of linear motor as a frame element instead of roller screws or toothed chain. Linear motors have higher dynamics of the movement and they can reach higher speed compared to other solutions, which guarantee increase of the machine productivity. The main importance is put not only on the functionality but also on the low price of this solution. The 3D model of the mechanism is created in the program Inventor 2009.
236

Lis LKDS 800 / Press LKDS 800

Kolbábek, Lukáš January 2012 (has links)
The present Master´s thesis deals with the concept of press drive of Blanking press LKDS 800 used for blanking in automatic blanking line. The first part of the thesis is dedicated to the individual arrangements of press drives and servo press drives and to the description of main components. The second part of this thesis deals with the structural design of the drive. Based on the computation of the crank mechanism, several design solutions were suggested. From these solutions, the option with the lowest drive height is selected. This option, offers the computation of the main drive, flywheel, spur gearing and clutch/brake combination. This computation is followed by computations of individual construction nodes, which include a design and dimensioning of the individual joggles, shafts and bearings. The drawing of the press and clutch shaft assemblies with a list of items are also included.
237

Lis LKJP 630 / Press LKJP 630

Haman, Tomáš January 2012 (has links)
Master’s thesis deals with the design of the drive of the press LKJP 630, the configuration is a fixed range by the construction of LKJP. The thesis was ordered by partnership with company ŽĎAS, which is introduced. The first part is devoted to analysis of solved problems, it primarily contains the overview on forming machines, used drives and a description of their main parts. The second part deals with the drive itself, there is accomplished the design and performed the strength analysis of the major parts of the drive. Drawing documentation and bill of materials are included.
238

Výroba krytu / Production of casing

Hájek, Pavel January 2014 (has links)
This master’s project describes a proposal for manufacturing technology of a horizontal boring machine case. This case is manufactured by HESTEGO a.s. from a DC01 steel sheet, which is 2 mm thick and its production series is 200 pieces a year. Punching and bending were chosen as the most suitable methods from the considered manufacturing technologies. The theoretical part of the thesis includes a study of the chosen manufacturing technologies. Based on the analysis of the technological calculations and the available tools in the manufacturing company, a technological procedure was designed and these machines were chosen: punching machine TruPunch 5000 a servo-electronic press brake SAFAN E – BRAKE 100–3100. Technical and economical evaluation is also included in the proposal.
239

Pomocná jeřábová kočka licího jeřábu / Auxiliary crab for overhead foundry crane

Adam, Petr January 2016 (has links)
This master thesis deals with issue design of crab trolley. Concretely is acted about auxiliary crab trolley with required capacity 65 000 kg. This crab is on overhead crane, which is situated at hall of foundry. In particular chapters is processed design of lifting mechanism and travelling mechanism, which is amended to strength control of frame. This whole leads to output solutions, which is drawing documentation.
240

Návrh výroby krytu vany regulátoru / Production of Cover of Regulator Tank

Kudláč, Lukáš January 2017 (has links)
This master’s thesis deals with suggestion of production of sheet metal cover in Limid Mohelno s.r.o. Piece serves as cover of regulation device of rail vehicles with visual function and it’s manufactured from corrosion-resistant steel ČSN 17 240 with thickness 1 mm. Esthetical impression is ensured by grinded surface K240. The master’s thesis includes literary studies and problems of chosen technologies, technological calculations and choice of machines including tools. As the best manufacturing technology was chosen punching on TruPunch 1000 and bending on press brake SafanDarley E-Brake E-100. Technical and economical evaluation was made based on selected technology and compared with another manufacturing options.

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