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Mapping of lubricating film thickness of human big joints replacements
Bosák, Dalibor ; Hartl, Martin (referee) ; Vrbka, Martin (advisor)
This master’s thesis describes mechanism of lubricating film forming and its thickness in contact of a metal hip joint ball and a glass disc with chromium layer with presence of bovine serum as substitute of synovial fluid occured in a natural joint. Lubricating film thickness is evaluated by a thin film colorimetric interferometry, results are ploted at graphs representing dependence of lubricating film thickness on experiment duration or on mutual speed of articulating surfaces. There is described the influence of concentration of bovine serum and different kinematic conditions on lubricating film forming. From observed interferograms is apparent the adsorption of proteins to glass disc and femoral head surfaces, denaturation and formation of protein aggregations affecting the residual lubricating film thickness.
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Research and development of bearings for traction motors
Prášilová, Alena ; Čermák, Jan (referee) ; Vrbka, Martin (advisor)
This master’s thesis deals with construction design of cylindrical roller bearing for traction motor and design of life test tool for designed bearing. At the thesis beginning there is an overview of new trends in design of cylindrical roller bearing, according to new trends is designed a new construction design of cylindrical roller bearing. Other part of thesis is strain stress analysis, which assesses an optimal inclination of collar faces and optimal raceway modification of hybrid bearing rings. At the end life test will be analyzed.
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Influence of topography of rubbing surfaces on rolling contact fatigue
Zahradník, Radek ; Čermák, Jan (referee) ; Vrbka, Martin (advisor)
This master thesis deals with influence of topography of friction surfaces on rolling contact fatigue. This influence is examined by newly reconstructed R-MAT station, whose reconstruction and fully report about it, is part of this master thesis. Influence is examined on area with higher surface's roughness which it wasn't examined before. Further research is made on area of surfaces with topographical modification with higher surface's roughness.
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Design of frame of recumbent bicycle
Gayer, Tomáš ; Maňas, Pavel (referee) ; Vrbka, Martin (advisor)
The aim of this diploma thesis is evolution of the new model of tricycle. This thesis describes process of engineering from design of several parts and whole frame in CAD system Autodesk Inventor, to creating complete drawing documentation. Next part of this thesis is focused on basic static-structural analysis using finite element method in software ANSYS Workbench and determining boundary conditions for this analysis. The final part is about visualization of the new tricycle.
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Fluid flow analysis in vicinity of exhaust valve using CFD
Šesták, Josef ; Náhlík, Luboš (referee) ; Vrbka, Martin (advisor)
This diploma thesis discuss a flow in a vicinity of exhaust valve using computational of fluid dynamics. In a light of current state of the problem solution this approach is forward but very sophisticated. Intention of author is description of multidimensional boundary of characteristic variables which determinates the flow behaviour for given geometry and boundary conditions. Technical knowlegde of fluid flow in vicinity of exhaust valve allow to design geometry which provide more effective cylinder flush out berofe the exhaust stroke will become. This process reduce quantity of loss work of piston and improve its effective pointers.
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Design and realization of tutorial based on SEW Eurodrive gearmotors
Kantor, Martin ; Prášil, Ludvík (referee) ; Vrbka, Martin (advisor)
The thesis deals with a construction of solar tracker designed from the MayTec Profile System using SEW Eurodrive’s electric actuation and accessories. The work describes the design of a laboratory assignment which uses these elements. In the preface information is provided about the construction of solar trackers on which the thesis is based. The next parts of the text are dedicated to each step of the construction design and its variants. A description of how to activate the drive and the design of the connection scheme are also included as well as the technological and construction evaluation. The conclusion contains an economical evaluation of the whole construction.
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Design of mountain-bike crossbar and its FEM analysis
Jelínek, Martin ; Maňas, Pavel (referee) ; Vrbka, Martin (advisor)
The aim of this diploma thesis is the part of evolution of the new bicycle frame for mountain biking, category enduro. The first part of this thesis is focused on creating dimensional modified model of the bike frame in CAD system SolidWorks. Subsequently this frame will be detailed by FEM analysis in software ANSYS Workbench and determine boundary conditions for this analysis. The final part is about visualization of the new bike frame.
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Computational modelling of strain and stress in spur gearing using FEM
Ševčík, Martin ; Maňas, Pavel (referee) ; Vrbka, Martin (advisor)
This diploma thesis deals with computation modeling of spur gearing using FEM. The methodology of checking calculation was suggested for gears which are not possible to check only by using standard ČSN 01 4686. The analysis of influence of vicinity of stress concentration on stress distribution in tooth root was performed. It is possibility to use the gears with thinner rim than the standard ČSN 01 4686 recommends. The main part of this work is devoted to fatigue crack propagation study in gears with thin rim. Aiding T-stress the influence of constraint and stress multiaxiality on crack propagation was taking into account. The predicted fatigue crack propagation paths were compared with certain experimental data. It is demonstrated that the considering of influence of constraint improves estimation of consequent crack propagation direction and in some cases the influence of constraint can significantly change the estimated crack propagation path.
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Review of methods to determining wear in hip replacements
Zapletal, Jakub ; Vrbka, Martin (referee) ; Ranuša, Matúš (advisor)
This bachelor thesis analysis issues of observation and measurement of wear on hip replacements. First of all there is a description of historical milestones in development of hip prosthesis. Afterwards there is a recherché study of measuring methods and devices, whereas each one of them is reviewed for pros and cons. In the last section these methods are compared and there is an author’s recommendation for the most viable method for observation and measurement of wear on hip prosthesis.
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