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Final machining technology of a special bearing ring using a grinder on the holes
Růžička, Daniel ; Kalivoda, Milan (referee) ; Chladil, Josef (advisor)
The main goal of this thesis is to compare 5 chosen grinding wheels, that vary by the material and structure. The testing is done in the company SLB, spol. s r.o., using a grinder on the holes BDU 80, which is set to 6 different settings of the grinding cycle, defined by the letters A´, A, B, C, D and E. These settings vary by the cutting conditions and enable to compare the tested grinding wheels by 8 measured parameters of the surface quality of the grinded bearing orbits of outer rings of the SLB 84-74 bearings, that are described by the drawing documentation.
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On the Effective Machining of New Ceramic Materials
Sámelová, Vendula ; Sedlák, Josef (referee) ; Vrba, Vladimír (referee) ; Humár, Anton (advisor)
Advanced ceramics have long held the front of the list of promising materials for high-tech applications. The most common problem is the high cost of design, production and machining of advanced ceramics parts. The main sense of advanced ceramics processing techniques development is affordable, high-volume production. The dissertation is focused on SiC silicon carbide grinding. SiC is used in the design of machine parts due to its excellent properties The deep knowledge of the diamond wheel grinding process is important because it is one of the finishing methods and therefore has a direct impact on the quality and strength of the SiC parts. The key issue here is the overall surface quality of the parts after diamond wheel grinding and the knowledge of the factors that influence the surface quality. These include, in particular, grinding vibrations. The main purpose of the thesis is to create a system of specific scientific and technical information, which will allow applying optimal technological procedures in the processing of ceramic components. The theoretical part of the thesis contains an analysis of the current state of the art in the advanced ceramics machining area, detailed analysis of the ceramics grinding with diamond grinding wheels, signal analysis theory and analysis of surface quality assessment methods. The experimental part contains analysis and discussion of the results obtained during the monitoring of the silicon carbide grinding process with a diamond grinding wheel. Various diagnostic methods have confirmed the presence of vibrations at a frequency close to the speed frequency of the grinding wheel, which had a significant, negative effect on the samples surface quality. Vibration diagnostics has identified a specific source of vibration (clamping of the workpiece) and it has been removed subsequently.
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Monitoring the effect of sample treatment in determining selected properties of biofuel
Štenclová, Kristýna ; Lachman, Jakub (referee) ; Lisá, Hana (advisor)
Diploma thesis is focused on the treatment of biofuel prior to combustion and effect of this treatment on the biofuel characteristics. The first part is a review of literature encompassing characteristics of fuel, preparation of samples, methods of analysis of individual characteristics and a presentation of various types of mills. The second part of thesis is experimental. It is an analysis of sample characteristics under various mill settings with regard to the temperature in the mill during grinding.
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The proposal of advanced production technology of steel molds
Opršál, Radek ; Prokop, Jaroslav (referee) ; Kalivoda, Milan (advisor)
The bachelor thesis deals with the modernization of steel mould production in the company P-D Refractories CZ a.s. The thesis focuses on the analysis of current production technology, determination of the bottleneck in production, and the analysis of the possibilities of modification of current technologies. The last part of the thesis proposes the most optimal methods of solution, introduces the technical procedure modified for the new solution and presents the evaluation of the data.
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Technological parameters of abrasive process
Řehák, Pavel ; Bumbálek, Bohumil (referee) ; Prokop, Jaroslav (advisor)
In this work, there is described an abrasive process including technological terms with an identification of motions and a speed of grinding.Then there are described abrasive tools, their distribution and description. In the last part there are introduced some reached parameters of the accuracy and characteristics of the surface structure in dependence on the length of abrasive process.
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An analysis of the heat-affected surface layer after grinding of the bearing rings
Filípek, Timotej ; Kalivoda, Milan (referee) ; Jaroš, Aleš (advisor)
The object of this bachelor thesis is a determination of the causes of burns origin at the surface layer of a workpiece after a grinding process and their elimination. The first chapter is focused on the description of the grinding technology, grinder types and grinding tools. The second chapter deals with the characterisation of the process fluids, their use and suitability depending on the cut conditions and the material. The third chapter explains what a burn is, the causes of its origin and the ways of subsequent elimination of this adverse event. The experimental part – performed in the Schaeffler Skalica, spol. s r.o. company – deals with the origin of the heat affected surface layer due to improper dressing grinding parameters and improper choice of intervals between dressing processes of the grinding wheel. At the experiment two different grinding wheels were used; subsequently, they were compared to each other from the point of view of suitability for the machining process. The final chapter comprises the experimental part assessment and a summary of the findings in this topic.
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The influence of grinding on the limestone properties
Pavlík, Tomáš ; Bednárek, Jan (referee) ; Šiler, Pavel (advisor)
This bachelor thesis deals with dry limestone grinding in the vibratory mill and ball mill. Three different limestone samples were used for milling. Samples were ground in the mills without the addition of surfactants. Several methods of grinding were performed in the vibratory mill. At first, the same weight of limestone samples was ground for different grinding time without any interruption except for one case of grinding with breaks for cooling off the grinding tablet. Another method was grinding of different weights of the same sample. The last one used the same weight of different samples. In the ball mill, sample of one type of limestone was ground for various milling time. The particle size, shape of particles, phase composition and crystallite size were studied for the ground samples. Sieve analysis, laser diffraction analysis, scanning electron microscopy, powder X-ray diffraction analysis and X-ray fluorescence analysis were used to determine these properties. For each mill, the amount of energy consumed for limestone grinding was calculated.
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Machine grinding
Beseda, Vojtěch ; Mouralová, Kateřina (referee) ; Kalivoda, Milan (advisor)
At the beginning of this dissertation an overview of grinding technologies is presented. The following chapter presents a selection of grinding machines from databases and manufacturers’ catalogues. At the end, a case study of grinding processes in a small manufacturing company is analysed. It focused on the action of grinding an internal cylindrical area on thin wall housing. The solution is the adaptation of component´s attachment, the adjustment of the working cycle and the dimensional control according to drawings.
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