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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.
261

Konstrukční návrh lineární osy pro těžký obráběcí stroj / Design of linear axis for heavy machine tool

Göbel, Lukáš January 2017 (has links)
The content of this thesis is the description the various component of the linear feed axis, which are used in heavy duty machine tools. This describes their features, advantages and disadvantages and on these basics, are selected different appropriate design variants. In the second part of this thesis has been drawn up constructional design of these variants. They were subsequently compared and then was chosen the most ideal one for the designed machine, which is heavy machine tool upper gantry type. The work also includes the 3D CAD model of the final version and drawing documentation.
262

Izolační systémy elektrických strojů malého a nízkého napětí / Low-voltage and low-voltage electrical machines insulating systems

Procházka, Jan January 2019 (has links)
This thesis describes properties of windings of electric rotating machines and their insulation systems. There are winding and insulation low voltage machines tests listed with their procedures and criteria. Further it deals with coordination methodology and the last part contains execution and results assessment of tests conducted on stator samples.
263

C osa pro vmÄnn© hlavy u fr©zovac­ch obrbÄc­ch center s vodorovnou osou vetena center smykadlov©ho typu / C axis for interchangeable heads for milling machining centers with horizontal spindle center of the slide type

Pekrek, Mojm­r January 2020 (has links)
This thesis deals with designing of C axis for interchangeable heads for milling machining centres with horizontal spindle centre of the slide type. Itâs divided into three parts, whereas the first part contains theoretical introduction to the problematic. The second part deals with systematic analysis of the topic and choosing the right variant for elaboration. The last part forms construction design of the chosen variant, which contains notes on the solution proce-dure, calculations and visualization in form of 3D models.
264

Sypné vlastnosti jemných partikulárních materiálů jako funkce vybraných látkových parametrů / Bulk properties of fine particulate solids as the function of the selected material parameters.

Slanina, Ondřej January 2014 (has links)
The theoretical part of the thesis focuses on the description of particulate materials and their mechanical behaviors with a focus on flow properties. Great emphasis is placed on measuring the shear properties using a Jenike shear machine, on the correct procedure for standardized measurement and evaluation using Mohr's circles. The theoretical part focuses on the characterization of particulate matter using a variety of methods available, such as visual, separation, sedimentation, surface methods and methods of scanning field and flow. The practical part is focused on the determination of flow characteristics and surface finishing of finely ground limestone Omyacarb VA with various grain sizes. The surface was modified using stearic acid and calcium stearate. Attention was paid to the influence of the concentration of surface-regulating substances on the flowability of the material. The flowability of commercially supplied material was compared with lab modified materials and the determination of the theoretical content of stearic acid or calcium stearate was accomplished. Shear properties were measured using the Jenike shear machine. The material was further tested by laser diffraction and SEM with EDS particle surface analysis and elemental surface mapping.
265

Analýza magnetického pole pomocí MKP a magnetické sondy / Magnetic field analysis with finite element method and magnetic sensor

Volf, Tomáš January 2010 (has links)
The magnetic field analysis by MKP and magnetic probe project deals with magnetic field analysis of asynchronous machine cross section. This analysis is written in detail along with the necessary theory of asynchronous machine and the ANSYS program. The magnetic field of selected machine is measured by magnetic probe and results are compared with calculation. The next part of thesis is draft of device for the magnetic field analysis.
266

Návrh, optimalizace a modelování provozních stavů synchronního stroje s permanentními magnety na rotoru / Design, optimization and full load circuit simulation of the surface mounted permanent magnet machine

Bláha, Martin January 2013 (has links)
This thesis deals with the possibility of using the finite elements method for the analysing of synchronous permanent magnets machines. The aim of this work is to discuss the possibility of the machine design more effectively with using the finite elements method and Maxwell software for the simulations. On the created parametric model, simulations were performed according to master thesis assignment. The aim of this work is to determine induced voltage, iron losses, machine inductances and make a permanent magnets demagnetization analysis. From simulations results the machine efficiency is calculated. The parametric model was used for the optimization of selected parameters. From results of optimization new dimensions of permanent magnets was obtained. Machine efficiency was increased by new permanent magnet material and optimized design.
267

Pomocné vinutí pro napájení napěťového regulátoru synchronního generátoru / Auxiliary winding supplying the voltage regulator of synchronous generator

Hrtáň, Michal January 2014 (has links)
The theme of this thesis is the design and verification of the auxiliary winding to supply the voltage regulator of the synchronous generator. The synchronous generator for which the auxiliary winding proposed is three-phase, low voltage with double layer random wound stator winding. The generator excitation is brushless with auxiliary rotating exciter. The auxiliary winding is designed for placement in the stator teeth, along with the main winding. The sizing of the auxiliary winding is derived from the power requirements the voltage regulator. Draft winding is validated analytical calculation and finite element method (FEM). The auxiliary winding has been implemented in the production of the generator. The Features of the auxiliary winding have been verified by measuring the by electrical testing room and the test results are evaluated.
268

Analýza a návrh vinutí střídavých strojů / Analysis and design of the AC machines winding.

Vorel, Luboš January 2014 (has links)
This diploma thesis is focused on an analysis and design of an AC machines windings. In the theoretical part of the thesis, differences between single-layer and double-layer windings are explained. Next, the properties of a stator winding of synchronous machines are described. Finally, the winding factor is determined by means of a standard calculation method and by means of a new progressive calculation method, too. In the experimental part of this thesis, the stator winding of a high-speed synchronous generator excited by permanent magnets on the rotor is designed. This generator is driven by a steam turbine.
269

Analýza účinků zkratového proudu v rozváděči / Analysis of effects of short-circuit current in switchgear cabinet

Prokop, Jan January 2015 (has links)
The work is focusing on dynamic effects of short-circuit currents, more precisely dynamic effects of short-circuit currents on switchgear cabinet (terminal box). The work was designated to a concrete construction type of two switchgear cabinets located on rotating machines via company Siemens Electric Machines Drásov s.r.o.. The switchgear cabinets are designed for non-explosive environment where the air is used as an insulating medium. The task was to determine how the device will behave during the three-phase short-circuit and three-phase short-circuit with earth/ground connection. The following programs were used for the calculations and simulations: Ansoft Maxwell 16.0, Ansoft Maxwell 2015 and ANSYS Workbench 16.0. By using these programs the effects of forces which acts on current paths in cabinet caused by the passage of short-circuit current were simulated, statically and also dynamically. Further the effects of pressure acting on cabinet frame during the arc short-circuit have been statically and dynamically simulated. All the results are summarized in the conclusion. Conclusion also contains the final evaluation of the functionality of both switchgear cabinets.
270

Návrh a analýza synchronních strojů s permanentními magnety a soustředěným vinutím / Design and analysis of PMSM with concentrated winding

Macek, Pavel January 2015 (has links)
Permanent magnet synchronous machine (PMSM) are widely used in many industrial applications. This thesis starts with familiarization with the properties and structure of each type of synchronous machines with permanent magnets. Subsequently there are described properties and possible division of AC winding types. Afterward analytical designs of four machines with two different types of winding were realized. These designs were compared by means of simulations using the RMxprt program and their properties were subsequently verified by method of finite element using the Maxwell 2D program. Evaluation and comparison in terms of utility properties for all designs of machines were performed at the conclusion of this thesis.

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