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Design of clamping device for machining of manifold part
Foltýn, Jan ; Mazal, Pavel (referee) ; Svoboda, Petr (advisor)
This thesis deals with clamping fixtures. It aims to design an effective clamping solution for machining parts on a milling machine. The clamping solution was designed and then verified by a series of calculations. The main goal and partial objectives were fulfilled. The output is the design of fixture, which can clamp given part. Subsequently, based on the calculations it was decided to use four of these fixtures on one machining table. When calculating the appropriate variation of the fixture layout, an estimate of the time required for the operations performed by the machine operator was made. The thesis offers an overview of the materials used in the automotive industry. Furthermore, the study of clamps and clamping systems. It also touches the problem of optimizing manufacturing process and demand for ways to speed up the manufacturing process.
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Draft production line for light transmitting LiCrete blocks
Caletka, Tomáš ; Čížek, Petr (referee) ; Mazal, Pavel (advisor)
The aim of this thesis is to design a production line for manufacturing of light transmitting bricks LiCrete. This brick is a special interior design component which is made of concrete and light transmitting parts. It’s manufactured by casting into the dismountable molds. The research part explains manufacturing technology and possibilities to build production line. The concept solution part is about two concepts of production line and about a few ways how to integrate vibration machine into the line. Main part of the thesis describes mechanical design solution with focus on manipulators and vibration part. Last part of the thesis is about design of automation integration into the production line.
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Mechanical design of rotary satellite antenna polarization system
Vítek, Petr ; Mazal, Pavel (referee) ; Paloušek, David (advisor)
The aim of this bachelor thesis is mechanical design of rotary satellite antenna polarization system. It is a part of a mobile satellite antenna positioned on the roof rack of a passenger car. Device must be designed to achieve precise positioning and smooth running. It must also resist moisture and temperature fluctuations. For this application, there has been selected and developed solution with toothed belt. The thesis includes a selection algorithm of drive, belt and bearings. The achieved polarization angle is 180 °. The results of this paper can be used to produce a functional mobile satellite antenna polarization.
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Influence of dynamic loading on the contact fatigue characteristics of bearing material
Hložek, Jiří ; Hutař, Pavel (referee) ; Mazal, Pavel (advisor)
This thesis deals with the study of sudden step changes observed in model testing of standard bearing steel 100Cr6. Methodology of experiments with step change of load is proposed and applied in measurements. Three complete series of experiments were conducted, and rating life was determined for each loading trend. Based on the experiments carried out, it was found that the selected steel is able to withstand the sudden step of load changes, despite the fact that it is not material of choise for this type of load. Part of this work was to verify functionality of the innovated test stations AXMAT with modern diagnostics and a new control system, and also of the hydraulic variant of AXMAT, which allows to remotely derive dynamic loading of the test sample.
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Initiation and development of cyclic damage in steel for the energy industry
Horník, Vít ; Mazal, Pavel (referee) ; Věchet, Stanislav (advisor)
The main content of this master's thesis is a determination of the fatigue properties by using non-destructive testing methods – the acoustic emission technique and the X-ray diffraction. The reactor steel, that is named GOST 15Ch2NMFA, is used as a model material and is used to manufacture VVER-1000 reactor pressure vessels. The supplied material was made of two different steel melting, designated as H and S. For the basic measurement of the fatigue properties the stress-cycle asymmetry R = -1 was used. Some of the samples were used for approximate determination of the fatigue strength stress-cycle asymmetry R = 0. During the loading process the resonance frequency of the loading machine and acoustic emission signals were recorded. The changes in microstructure were estimated from the record of acoustic emissions during the whole fatigue life. The change of the microstructure was experimentally observed by X-ray diffraction analysis. The mechanism of the fatigue can be described by the observation of the microstructural processes as well as the relevant bifurcation with sufficient sensitivity. The results of the used methods indicate a decay and re-growth of mosaic blocks during the whole loading process. Therefore, it is important to find a correlation of these two non-destructive methods, or to use other non-destructive testing methods in the future.
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Diagnostics of rotating parts mounting systems in a wind turbine nacelle
Krontorád, Jakub ; Vlašic, František (referee) ; Mazal, Pavel (advisor)
The core aspect of thesis is management of work and diagnostics of wind turbines. It contains an overview of wind energy in Czech Republic and collects a relevant information from international papers and studies regarding the topic of diagnostics and maintenance of main mechanical components located in nacelle of wind turbine. It contains a recommendation for improvement of working conditions of wind turbines and their maintenance, which would lead to decrease of failure rates of the wind turbines main mechanical systems due to the utilization of acoustic emission and high frequency vibrations monitoring. Experimental part of the thesis contains analysis of acoustic emission signal from anonymous wind turbine with maximum energy output of 2000kW in Czech Republic to illustrate the sensitivity of acoustic emission and introduce its principles.
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Design of a milling table for machining wooden boards
Uhlíř, Radim ; Mazal, Pavel (referee) ; Čípek, Pavel (advisor)
The bachelor's thesis deals with the design and implementation of a milling table for machining wooden boards. In the research part, an analysis of the solutions available on the market was performed together with an analysis of workpiece fixtures, hand milling fixtures and linear guides. Based on the research, two conceptual solutions and several variants of structural nodes were proposed. The most suitable constructional solution was selected from the conceptual solutions, calculations of critical nodes were performed and drawing documentation was made. Subsequently, a prototype of the table was made and its functionality was tested. The table can clamp and machine a wooden board with maximum dimensions of 1000 x 800 x 100 mm.
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Modernization of R-mat test stations
Papaj, Lukáš ; Dočkal, Aleš (referee) ; Mazal, Pavel (advisor)
The aim of the thesis is to reconstruct obsolete R-mat test stations, which are used for rolling contact fatigue tests of material, which are still of interest from industry. It was necessary to replace the original control electronics with a new industrial computer to allow use modern sensors and automate the entire test process. At the same time, the measurement was supplemented by an acoustic emission method, which can also record the development of damage. Design modifications have been made that allow the installation of all new sensors. The main method for evaluating the tests is vibrodiagnostics, which is supplemented by the acoustic emission method. With the help of several experiments, the shortcomings of the new control system were identified, some parameters were designed, and the main functionality of the modernized R-mat station was verified. According to the proposed parameters and the identified shortcomings, the control system was modified, and a script was created, which is used to evaluate the test. It is still possible to perform rolling contact fatigue tests of the material on the modernized equipment, and thanks to the modernization of the electronics, it is possible to test completely new methods of test evaluation.
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Methods for solving the tolerance chains
Fiala, Lukáš ; Mazal, Pavel (referee) ; Svoboda, Petr (advisor)
This bachelor’s thesis deals with methods of solving dimensional chains. At the beginning, basic terms related to dimensional chains are explained. The next section describes worst case, statistical, group interchangeability and compensation methods. For better explanation, an example is solved for each method. Attention is also paid to systems in which the calculation of tolerance analysis can be performed. In conclusion, statistical and compensatory methods are used at the same assembly for comparison, and then, results are compared and evaluated. The thesis should provide the reader, in which cases it is appropriate to use a certain method.
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