|
|
The Possibilities of Displacement Increase of 4C Zetor Engine
Zloch, Jan ; Franz, Rudolf (referee) ; Dundálek, Radim (advisor)
Diploma thesis aims on mechanical design of new concept of Zetor UŘ III engine with displacement increase and solves calculations of main and pin hydrodynamic bearings of crankshaft. Creo 2 CAD software is used for preparing mechanical design of this new concept. For computation and analysis of hydrodynamic bearings multibody model of crankshaft mechanism is used with flexible FEM model of crankshaft for solving dynamics of mechanism and performing hydrodynamic analysis of bearings in FEV Virtual Engine. Results of this diploma thesis demonstrate the feasibility of new concept of engine and serve as a basis for next engineering tasks before realization of concept.
|
|
| |
|
| |
|
|
Dynamics of Turbocharger Rotor using Slide Bearings based on MBS
Hromádka, Adam ; Knotek, Jiří (referee) ; Novotný, Pavel (advisor)
The first part of the thesis describes construction of turbochargers. The next chapter summarizes currently used methods to solve dynamics of vehicle turbocharger´s rotor. Build-up of the model of a rotor and substitution of a joint with a bearing is appended with advantages and disadvantages. Practical part of the thesis focusses at analyse of a specific rotor of turbocharger with use of MBS. Output of the analyse are rotor´s vibrations. Last chapter complains methods to improve the model.
|
|
|
Research of Coatings of Hydrodynamically Lubricated Sliding Bearings for Combustion Engines
Repka, Martin ; Čermák, Roman (referee) ; Petrůj, Jaroslav (referee) ; Havlica, Jaromír (advisor)
Hlavní náplní této dizertační práce je výzkum a vývoj nové povrchové vrstvy pro kluzná ložiska na bázi pevných lubrikantů v polyamid-imidové polymerní matrici se zlepšenými tribologckými vlastnostmi. Podklady pro materiálovou kompozici vzešly z expertízy komerčně dostupného povlaku, respektive jeho povrchovou analýzou v mezných operačních podmínkách. Charakterizace mazného oleje před a po tribotestování společně s detailní povrchovou analýzou dala podmínky pro vznik materiálové formulace. Další část práce se zabývá studiem přípravy a vývojem aplikačního nanášení s přípravou polymerní směsi. Nakonec je popsána studie vlivu sulfidu molybdeničitého a grafitu, jakožto pevných lubrikantů pro zlepšení třecích vlastností a hydroxidu vápenatého pro potenciální zpepšení otěruvzdornosti výsledného povrchu pro palikaci kluzných ložisek.
|
|
|
Diagnosis of mechanical vibrations in asynchronous motor origin
Dostál, Martin ; Dostál, Lukáš (referee) ; Janda, Marcel (advisor)
Every machine needs to be maintained and controlled, if may work reliably during they service life. Big part of service life of expensive machines are those machines in operation. Vibration diagnostics is type of analysis, that doesn’t need removal of rotation machinery. The vibration, that are created by running machinery, are used as source of information about mode of operation. This master’s thesis contains theoretical analysis of vibration diagnostics and vibration measurements of a particular machine. This thesis contains 3D models of bearings and rotor asynchronous machine, which are created by software Autodesk Inventor 2014. Bearings vibration analysis of this models is performed by software Ansys Workbench.
|
|
| |
|
|
Turbocharger Vibrations Generated by Internal Combustion Engine
Schulla, Radek ; Vacula, Jiří (referee) ; Novotný, Pavel (advisor)
The content of this master’s thesis is the issue of turbocharger vibrations due to excitation from the internal combustion engine. The theoretical part deals with the noise and vibrations generated by turbochargers and internal combustion engines. It also discusses the effect of vibration on the turbocharger and its individual parts, including the effect of the internal combustion engine. Subsequently, a turbocharger model is created in ADAMS software, the rotor response in turbocharger operating speeds to various excitation frequencies is analyzed and finally the safety of fluid bearings is evaluated and modifications to reduce vibrations are proposed.
|
|
|
The effect of texture geometry on friction and lubricating film formation in radial journal bearing
Katrincová, Tereza ; Čermák, Jan (referee) ; Šperka, Petr (advisor)
The aim of this diploma thesis is to find out how the geometric parameters of circular textures affect the friction and lubrication in a conformal contact. The configuration of a partial, radial, hydrodynamic bearing was investigated on a modified block on-ring device, where the block was replaced by a sapphire section. The device allows simultaneous measurement of friction and optical observation of processes in contact. The light induced fluorescence method was used for the measurement of film thickness. None of the studied texture combinations had a positive effect on the transition from hydrodynamic mode to mixed lubrication mode. Textures in the narrow band of the combination of diameter and depth have a positive effect, outside of them negative effect of texture on friction and film thickness was observed.
|
|
|
Experimental study of fluid-induced instabilities in journal bearings
Stifter, Jan ; Polach, Pavel (referee) ; Omasta, Milan (advisor)
Presented diploma thesis deals with experimental study of fluid induced instabilities which occur in rotating machinery with journal bearings. The first part describes the oil whirl and oil whip instabilities. It also gives an example of optical methods used for observation of journal bearings. Next part is dedicated to modifications of an existing test rig that were necessary for carrying out experiments. Finally, there are presented results of experiments that define the effect of initial conditions on appearance of instabilities.
|
guest ::
