National Repository of Grey Literature 50 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Computational analysis of operational deformations of the diesel engine cylinder unit
Zalibera, Tomáš ; Řehák, Kamil (referee) ; Dlugoš, Jozef (advisor)
Submitted diploma thesis deals about operational deformations in the cylinder unit of turbocharged diesel engine used in commercial vehicles. Introductory part analyses combustion engines computational modelling based on finite element method. The next step is the creation of computational models for thermal-structural analyses of the piston and engine block. In order to determine material characteristics of the head gasket, experiment is performed on the OEM gasket to determine its real behaviour under compressive load. The results shows strong nonlinear behaviour which justifies the decision of making such an experiment in the first place. The results of computational models are radial deformations of the piston and cylinder liners during load conditions. The last chapter deals with the application of these results to an advanced computational piston assembly dynamics model.
Vibroacoustic Analysis of the Combustion Engine
Špačková, Jana ; Řehák, Kamil (referee) ; Prokop, Aleš (advisor)
This thesis is focused on vibration and noise diagnostics of a combustion engine. In the range of the current knowledge there is an analysis of measuring devices, units of measure, possibilities of frequency analysis and a combustion engine from the point of view of vibrations and noise. Part of this work is creating a technical experiment where there were measured both vibrations and noise of two combustion engines. From the data it was done a frequency analysis. Conclusion of the analysis is an evaluation of frequencies which occurred on given engines.
Design of a rubber coupling for railway applications
Blach, Jiří ; Prokop, Aleš (referee) ; Řehák, Kamil (advisor)
The diploma thesis deals with the design and stress-strain analysis of a flexible coupling composed of individual rubber-textile segments. This concept allows the manufacturer to simplify and unify the production thanks to the ability to use a single segment design for multiple coupling configurations and thus leads to a reduction in costs on the part of the manufacturer. From the consumer side this allows only mechanically or chemically damaged segments to be replaced instead of the entire coupling and saves costs for the potential user. The coupling assembly is primarily designed according to the parameters of intercity electric units and locomotives, however, the individual flexible segments are not limited by this use. When designing a coupling assembly, it is necessary to place requirements primarily on the high safety of all components. The operating mode, in which the relative displacement of the input and output shafts can occur, indicates a relatively wide range of transmitted loads which, if any assembly part is improperly designed, can cause problems leading to temporary putting the entire machine/vehicle out of order. The most critical areas of the assembly include the flexible segments, the bolt connections, the strength of the hubs and the spline joint for torque transfer. Last but not least, the requirements for the non-complex production of components must be taken into account, together with the assembly and maintenance without collision of the components and the necessary tools. In order to verify the above-mentioned requirements, stress-strain analyses are performed simulating the variation of operating load conditions. Due to the reduction of hardware requirements and computational time, together with the absence of experimentally measured data of rubber and PES codes, the flexible segments were modelled at a lower level with a reduced material model favouring the tensile properties of PES cords. However, this reduction provides a more conservative approach, as this use causes higher stresses on the steel components of the assembly. Subsequently, a stress analysis of the splined joint is performed. Due to the absence of specific shaft geometry models of commercial motors and gearboxes, a parallel splines were chosen for this purpose and designed according to the specified maximum torque. The last part of the thesis is focused on verifying the tensile properties of an individual flexible segment.
Design of the Tractor's Cabin Suspension
Rekem, Jakub ; Řehák, Kamil (referee) ; Prokop, Aleš (advisor)
Diploma thesis is devoted to tractor cabin's suspension. First part of the work consists of the overview of used suspension designs and their various modifications. Next, law requirements for roll-over protective structure are described. Subsequently, the suspension design for small-sized tractor is explored. Law compliance is revised via ROPS procedure simulation using finite element method. In the last part of the work, virtual prototype of agricultural tractor in Multi-body environment is built and it is used for studying the dynamic characteristics of proposed cabin suspension design.
DPF for CI Engines
Hanák, Jiří ; Řehák, Kamil (referee) ; Dundálek, Radim (advisor)
This bachelor thesis describes formation of harmful particles during combustion cycle of diesel engine and blocking its spreading into atmosphere using diesel particulate filters. First part of this thesis looks into types and mechanisms of formation of these particles including regulations of its maximal value in atmosphere thanks to emission regulations. Then this thesis summarizes principles of diesel particulate filters´ functioning, their types, methods of construction and regeneration. Also, there are described systems of diesel particulate filters with diesel engine and practical solutions. In conclusion, this thesis deals with problematic combinations of diesel particulate filters and diesel engines and outlines possible future development.
High Pressure Injection Systems
Bernátek, Vojtěch ; Řehák, Kamil (referee) ; Dundálek, Radim (advisor)
This thesis focuses on high pressure injection systems. It features some types of diesel and petrol fuel system. There are presented advantages and disadvantages of these systems and their basic design analysis.
Design of military vehicles
Kroupa, Ondřej ; Prokop, Aleš (referee) ; Řehák, Kamil (advisor)
This bachelor thesis is focused on military vehicles and their construction. At first it is needed to divide them into categories by the valid Czech legislation. The issue of the crawler and wheel chassis is also important, as both have their advantages and disadvantages. The construction of the crawler chassis and the problematics of the construction on the basic wheel chassis components, which often differs from road vehicles, are analysed next. One of the important construction areas today are also the elements of protection, which can be passive or active. While designing the military vehicles, it is also necessary to take into account their special position within the legislation. The thesis addresses the problematics of emissions and noise rules, which is different from measures valid to road vehicles. In conclusion there is an indication of possible future development.
Design of wind power plant
Starý, Ondřej ; Dlugoš, Jozef (referee) ; Řehák, Kamil (advisor)
Renewable energy sources are currently a much-discussed issue. One of the possibilities of their use is the production of electricity using wind power plants. This work therefore describes in detail construction of wind turbines. At the same time, there is a brief evaluation of wind power plants, from an energy and economic point of view. Part of the work is also the calculation of the optimization of the gearbox weight and a description of the design of the wind turbine coupling.
Usage of transmission at electric vehicles
Běloušek, Ondřej ; Prokop, Aleš (referee) ; Řehák, Kamil (advisor)
At first bachelor thesis divides different conceptions of electric vehicles with the aim to describe characteristic components which electric vehicles contain, and that make it different in comparison with conventional cars. From the principle of the electric vehicle it is obvious that electric energy which is necessary for electric drive must be stored and for this reason the batteries and important components are described. The next part is dedicated to the powertrain which is affected by the presence or absence of an internal combustion engine and its usage rate. Common feature is an electric machine which transforms electrical energy into mechanical energy, and which makes powertrain complete. Gearboxes used at electric vehicles are the next part which is affected by the type of power unit that they cooperate with. For that reason, one representative from each part is described. The representative of hybrid electric vehicles is planetary gear set of Toyota Prius 2010, representative of battery electric vehicles is one-speed transmission of Tesla cars and in the end the multi-speed transmission is mentioned because it is today´s trend. Because of the absence of an internal combustion engine for some types of electric vehicles, the noise and vibrations from gearbox come to the fore. The main source of the vibration is gears teeth contact and rattle of the other components. The last part of the thesis is focused on the design of a technical experiment that is suitable for measuring vibration and noise from two-speed automatic transmission. Firstly, the theoretical basis of measurement is described. The design itself takes into account the suitable measuring equipment, the right choice of components that realize closed loop and installation space of the acoustic chamber.
Development of transmission
Kocman, František ; Prokop, Aleš (referee) ; Řehák, Kamil (advisor)
This bachelor thesis is focused on current trends of passenger car transmissions. The goal was to compile an overview of individual concepts with regards to the current trends. For each concept, there is a description of its construction and principle. The practical part is focused on the calculation of the basic parameters of a dual clutch transmission.

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