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Modelling the Oil Lubrication System of Turbocharger
Breckl, Lukáš ; Hliník, Juraj (referee) ; Novotný, Pavel (advisor)
The diploma thesis contains a research part focused on turbocharger construction, engine lubrication system and turbocharger, basic physical properties of lubricating oils and hydrodynamics. The purpose of this thesis is to create analytical and CFD computational model of turbocharger lubrication system. Output pressures and the loss of specific energy are determined.
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Research on the textured journal bearings for engines in automotive
Svoboda, Martin ; Hartl, Martin (referee) ; Omasta, Milan (advisor)
The aim of this thesis is to describe the effect of surface textures of radial journal bearings with polymer coating on friction and damage development using experimental tests. Wear and friction tests of real bearings with different texture geometries and surface materials were performed. It was found that the wear deterioration of the textured aluminum sliding bearing surface and neutral or positive effects on the wear of the textured bearing with polymer coating. The reason for the improvement is the good resistance to high pressures of the polymer coating and the preservation of the texture dimensions throughout the bearing run. The friction test showed an improvement in the frictional properties of the textured surfaces when the amount of lubricant in contact was insufficient. At the same time, a positive effect on tribological properties was demonstrated by reducing the lateral lubricant discharge.
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Computational Analysis Of Dynamic Behaviour Of Journal Bearings
Rak, Vladimír ; Kamenický, Ján (referee) ; Pochylý, František (referee) ; Zapoměl, Jaroslav (referee) ; Malenovský, Eduard (advisor)
This work deals with computational modelling of static and dynamic analyses of journal bearings, with analyses of stability of oil-film motion and analyses of response of the rotor assemblies. At our workplace a new theoretical approach to the modelling of the static and dynamic behaviour of the rigid rotating body in liquid is used. The approach is based on the application of the Navier-Stokes motion eq., equation of continuity and boundary conditions eqs. It is possible to separate the motion of the rigid body and liquid from each other using suitable transformation relations and then it is also possible to separate the stationary and nonstationary motions from each other. A method of control volumes is used for these analyses. The real Bézier body is used for the description of the geometrical configuration and also for the approximation of velocity and pressure functions. Combined the ALE (Arbitrary Lagrange-Euler) method is used, because it´s necessary to generate a new net (to perform new meshing) for a change of the shaft position. The additional effects of the liquid (additional mass, stiffness and damping), which we solved in dynamic analysis, are the function of the single parameter only – the shaft-centre position. There is a large advantage in comparison with the standard approach, which is based on application of the Reynolds liquid eq. Author solving the models of the long and short journal bearing with different geometry, especially the elliptical and cylindrical bearings, with incompressible and compressible journal bearing liquid. If the journal bearing problem is solved, it is possible to include the additional effect of the liquid to the right side of the motion equation of a model rotor assembly. Author analyze a model rotor assemblies with two degrees of freedom, which is supported inside of the two journal bearings on the ends of the rotor (Jeffcott rotor assembly). Author modelling and solveing a response of the model rotor assembly on the forced steady-state vibrations, which was actuating by the unbalanced matter.
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Balancing Shafts Support Optimalization for Zetor 4V UŘ III Engine
Zemčík, Tomáš ; Franz, Rudolf (referee) ; Rauscher, Jaroslav (advisor)
To make a check of an contemporary balancing verification of diesel engine Zetor UŘ III with type identification 1505, the engine power 90 kW and especially friction bearing design, which could replace existing needle bearing HK 4520 type, is the aim of this diploma thesis. Bearing type modification requires constructional adjustment of engine block and balancing shaft and therefore this proposal for construction another aim in my diploma thesis. The last part of my diploma thesis is an economic balance original imposition against newly designed. Calculations are made using mathematical software MathCad, the balancing shaft is made using ProEngineer software and control calculations of bearing stresses are made with ADAMS and FEM of ANSYS system. Motivation to write this work is to prove the possibility how to decrease manufacturing costs of ZETOR TRACTORS a.s. company.
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Experimental Determination of Turbocharger Mechanical Losses
Kudláček, Petr ; Doman, Jozef (referee) ; Novotný, Pavel (advisor)
This master’s thesis deals with mechanical losses in turbochargers. The theoretical part provides general information of the methods of support the turbocharger rotor, then focuses on hydrodynamic bearings. The thesis analyzes the occurrence of mechanical losses and the effects that affect them. An important part of this thesis focuses on the determination of mechanical losses and their possibilities. A test stand was compiled for the possibility of experimental measurement of mechanical losses. Several test measurements were performed on this test stand at different operating modes. Simultaneously, the determination of mechanical losses was performed using two other methods. Based on these measurements, it was also possible to perform an evaluation and analyze the occurrence of mechanical losses depending on the set operating conditions. A comparison of individual methods for determining mechanical losses performed in the experimental part was performed. At the end of the thesis, the possibilities of the test stand were defined based on the performed measurements.
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Advanced Methods for the Solution of Journal Bearing Dynamics
Maršálek, Ondřej ; Louda,, Petr (referee) ; Furch, Jan (referee) ; Novotný, Pavel (advisor)
Náplní této disertační práce je popis komplexní a obecně použitelné strategie výpočetního modelování chování kluzných ložisek, pracujících v režimu smíšeného mazání a uvažujících reálné struktury drsných povrchů obou členů kluzných ložisek – ložiskových pánví a ložiskových čepů. V práci jsou uvedeny a detailně popsány způsoby získání charakteristických popisných dat těchto drsných povrchů a její nedílnou součástí je i popis numerických algoritmů, sloužících k následnému zpracování těchto dat. Dále jsou zde rozebrány implementované výpočetní přístupy k modelování kontaktního tlaku. Ovlivnění hydrodynamické mazací vrstvy kluzných ložisek je dáno velikostí a průběhem faktorů toku, jejichž numerické stanovování je zde detailně popsáno. Alternativní stanovení faktorů toku pomocí analytických funkcí je zde pro úplnost rovněž obsaženo. V závěru práce je uveden popis numerického řešiče modelování chování kluzných ložisek spolu s uvedenými výsledky provedených simulací a jejich diskuzí. Ověření jednotlivých výpočetních modelů, popřípadě porovnání výsledků s výsledky získanými alternativním způsobem, je uvedeno v příslušných kapitolách.
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Modern slide bearings
Lesák, Tomáš ; Raffai, Peter (referee) ; Maršálek, Ondřej (advisor)
This bachelor thesis is professional research dealing with an overview of slide bearings in current use and their advantages and disadvantages compared with ball and roller bearings. It also describes the design, manufacturing technology, materials used for the manufacture of plain bearings, their coatings types and lubrication which are important factors in the life of the bearings.
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