723 results on '"Řehák, Kamil"'
Search Results
2. Vibroacoustic Diagnostics Based on the Experimental and Numerical Approach
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Zajac, Roman, Otipka, Václav, Prokop, Aleš, Řehák, Kamil, Herisanu, Nicolae, editor, and Marinca, Vasile, editor
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- 2021
- Full Text
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3. Acoustic and Vibration Response Analysis of Heavy-Duty Gearbox
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Rehak, Kamil, Prokop, Aleš, Zajac, Roman, Otipka, Václav, Herisanu, Nicolae, editor, and Marinca, Vasile, editor
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- 2021
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4. Numerical Dynamic Analysis of Gearbox Behaviour
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Otipka, Václav, Zajac, Roman, Rehak, Kamil, Prokop, Aleš, Herisanu, Nicolae, editor, and Marinca, Vasile, editor
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- 2021
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5. Application of Virtual Prototype to Heavy-Duty Gearbox Housing Evaluation
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Rehak, Kamil, Kucera, Pavel, Prokop, Ales, Kacprzyk, Janusz, Series Editor, Gopalakrishnan, Kasthurirangan, editor, Prentkovskis, Olegas, editor, Jackiva, Irina, editor, and Junevičius, Raimundas, editor
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- 2020
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6. Multi-Body Model of Agricultural Tractor for Vibration Transmission Investigation.
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Rekem, Jakub, Janečková, Radka, Otipka, Václav, Prokop, Aleš, Řehák, Kamil, and Žlábek, Pavel
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FARM tractors ,MODAL analysis ,TIRES ,BUSHINGS ,TRACTORS - Abstract
This article analyses vibration transmission on agricultural tractors with the excitation from the road to the driver's seat. A multi-body model of agricultural tractors created in Adams is presented. The main parts for the investigation of vibration transmission are the tractor body, where the only suspension elements are tyres, the tractor cabin, spring-dampers suspended at the rear and bushings at the front, and the driver seat with its pneumatic spring. A series of measurements were performed, and the model was validated using vertical acceleration values on the tractor body at four different locations. The FTire model (physical FEM-based model) was chosen to describe the behaviour of tyres. The model was created using measured tyre characteristics. Measured characteristics of spring-dampers and front cabin bushings were also implemented. For comfort investigation, ride simulations on ISO 5008 rough roads were performed. The transmission of vibrations in ride simulations was examined. A modal analysis of the linearised model was performed to confirm assumptions of the contribution of suspension elements to overall vibration levels. Finally, three case studies were conducted to better understand the model's vibration transmission properties. [ABSTRACT FROM AUTHOR]
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- 2024
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7. An Initial Case Study of the Computational Modeling of Cord-Rubber Segments
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Láštic, Daniel, Řehák, Kamil, Prokop, Aleš, Krpalek, David, Šplíchal, Jan, Žlábek, Pavel, Láštic, Daniel, Řehák, Kamil, Prokop, Aleš, Krpalek, David, Šplíchal, Jan, and Žlábek, Pavel
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This paper presents an initial study of the computational modeling for determining the stress-strain behavior of the cord-rubber segment, tailored to be used as a flexible member in the construction of torque transfer coupling in railway vehicles. The presented computational models use the multibody simulation approach for the assessment of segment deformation under diverse loading characteristics. The results are then used in the finite element computational models of the cord-rubber segment. The computational model is validated through tension tests of cord-rubber segments. The homogenized and microstructural models show their ability to simulate the overall stiffness of the segment relatively accurately in tension, but they are limited in not being able to include the influence of the segment's manufacturing technology. The micro-scale computational model then incorporates realistic representations of cord bundles, considering various cross-sectional shapes, whereas a very important factor significantly influencing the correlation of the results of the technical experiment and simulation is the consideration of the manufacturing technology in the process of building the computational model. The results show that the computational modeling approach in this work can be used for the determination of the optimal manufacturing technology conditions with regard to the stress-strain behavior of the given segment.
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- 2024
8. Vibroacoustic Diagnostics Based on the Experimental and Numerical Approach
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Zajac, Roman, primary, Otipka, Václav, additional, Prokop, Aleš, additional, and Řehák, Kamil, additional
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- 2020
- Full Text
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9. Gear Drive System Simulation of Input Parameters Effect on Rattle
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Prokop, Aleš, Kopečková, Barbora, Řehák, Kamil, Herisanu, Nicolae, editor, and Marinca, Vasile, editor
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- 2018
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10. Gear Drive System Simulation with Different Model of Input Speed
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Řehák, Kamil, Kopečková, Barbora, Prokop, Aleš, Herisanu, Nicolae, editor, and Marinca, Vasile, editor
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- 2018
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11. Static transmission error measurement of various gear-shaft systems by finite element analysis.
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Czakó, Alexander, Řehák, Kamil, Prokop, Aleš, Rekem, Jakub, Láštic, Daniel, and Trochta, Miroslav
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MEASUREMENT errors , *GEARING machinery , *HELICAL gears , *GEARING machinery vibration , *FINITE element method , *SPUR gearing - Abstract
Transmission error (TE) is a significant parameter related to gears vibration widely investigated by many authors using different approaches. However, in previous studies, spur and helical gears were mainly examined. There is a lack of studies addressed to double helical and herringbone gears and a comparison among several types of gearing with parallel axes. In this paper, spur, helical, double helical, and herringbone gears are analyzed in terms of static transmission error (STE), contact pressure and tooth root stress. Static contact analyses were conducted using the finite element method (FEM) which is often considered a tool for validating other methods and approaches. Moreover, three variants of boundary conditions of each gear type are introduced, including flexible shafts and the effect of a tip relief modification at sole gears, without shafts, was analyzed. In addition, a concept of a compact test rig intended for STE measurements at low loads was presented. The results have shown, among other things, significant influence of the shaft stiffness and boundary conditions on meshing characteristics. [ABSTRACT FROM AUTHOR]
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- 2024
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12. Static transmission error measurement of various gear-shaft systems by finite element analysis
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Czakó, Alexander, Řehák, Kamil, Prokop, Aleš, Láštic, Daniel, Rekem, Jakub, Trochta, Miroslav, Czakó, Alexander, Řehák, Kamil, Prokop, Aleš, Láštic, Daniel, Rekem, Jakub, and Trochta, Miroslav
- Abstract
Transmission error (TE) is a significant parameter related to gears vibration widely investigated by many authors using different approaches. However, in previous studies, spur and helical gears were mainly examined. There is a lack of studies addressed to double helical and herringbone gears and a comparison among several types of gearing with parallel axes. In this paper, spur, helical, double helical, and herringbone gears are analyzed in terms of static transmission error (STE), contact pressure and tooth root stress. Static contact analyses were conducted using the finite element method (FEM) which is often considered a tool for validating other methods and approaches. Moreover, three variants of boundary conditions of each gear type are introduced, including flexible shafts and the effect of a tip relief modification at sole gears, without shafts, was analyzed. In addition, a concept of a compact test rig intended for STE measurements at low loads was presented. The results have shown, among other things, significant influence of the shaft stiffness and boundary conditions on meshing characteristics.
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- 2023
13. Experimental Validation Of The Gearbox NVH Parameters
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Prokop Aleš, Řehák Kamil, Zubík Martin, and Novotný Pavel
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TRANSMISSION ,VIBRATION ,NOISE ,GEAR MESH STIFFNESS ,EXPERIMENT ,PŘEVODOVKA ,VIBRACE ,HLUK ,TUHOST OZUBENÍ ,MĚŘENÍ ,Machine design and drawing ,TJ227-240 - Abstract
The noise, vibration and harshness (NVH) plays an important role in the transmission area of automotive industry. To understand all the impacts on the gearbox’s global dynamic behavior it is necessary to gain information from a simplified model, create methods and get an appropriate and well correlated results with the experiment. The method itself can be afterwards reused for more complex transmission, which could be supported by other measurements. This paper deals with creation of a gearbox’s simplified model, including essential mechanisms as gear mesh stiffness, backlash, bearing stiffness and modal properties of the main components. Except for the presented model, more models with different difficulty levels are used. Numerical results are compared with data from experiment with good correlation.
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- 2015
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14. Gear Drive System Simulation with Different Model of Input Speed
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Řehák, Kamil, primary, Kopečková, Barbora, additional, and Prokop, Aleš, additional
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- 2017
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15. Gear Drive System Simulation of Input Parameters Effect on Rattle
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Prokop, Aleš, primary, Kopečková, Barbora, additional, and Řehák, Kamil, additional
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- 2017
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16. Analytical Investigation of Sound Radiation from Functionally Graded Thin Plates Based on Elemental Radiator Approach and Physical Neutral Surface
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Singh, Baij Nath, primary, Hota, R. N., additional, Dwivedi, Sarvagya, additional, Jha, Ratneshwar, additional, Ranjan, Vinayak, additional, and Řehák, Kamil, additional
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- 2022
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17. Modal properties diagnostics of the high-pressure fuel injection pipes in off-road diesel engine
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Otipka, Václav, Zajac, Roman, Prokop, Aleš, Řehák, Kamil, Otipka, Václav, Zajac, Roman, Prokop, Aleš, and Řehák, Kamil
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Injection systems of modern commercial vehicle power units are still a frequent topic for development engineers in terms of durability and reliability. Therefore, the content of this study is just an investigation of the dynamic behaviour of high-pressure injection pipes of a four-cylinder combustion engine. The modal properties of the injection tubes are evaluated by experimental modal analysis (EMA). Another phase of the measurements is the sensing and analysing of the acceleration on each injection pipe during the engine speed ramp in the entire range of the speed spectrum. There was investigated the modal behaviour of the structure to the operational character of the excitation. The work includes a numerical model established by finite element method (FEM), where the boundary conditions correspond to the real installation of injection pipes from the measurement. The modal properties of injection pipes were primarily investigated through the numerical approach, several variants of pipe attachments were considered in simulations. Comparing the FEM results of different pipe attachments, the suitability of the clamp position with respect to the specific installation in the power unit from the measurement is discussed. From the evaluated results, it is possible to assume the dynamic behaviour of the high-pressure injection pipe in the power unit. Based on the performed analyses, the critical mode shapes of the injection pipes are described considering the engine operating condition. When the engine speed frequency and some pipe eigen frequency interfere together, it is undesirable state. In many cases, this leads to a crack initiation and subsequent damage of the injection pipes during the cyclic load. The presented results and conclusions in this study should improve the overall knowledge on high-pressure fuel pipes in terms of modal properties and its vibration behaviour during operating condition.
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- 2021
18. Modal properties diagnostics of the high-pressure fuel injection pipes in off-road diesel engine
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Otipka, Václav, primary, Zajac, Roman, additional, Prokop, Aleš, additional, and Řehák, Kamil, additional
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- 2021
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19. Determination of static transmission error of helical gears using finite element analysis
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Czakó, Alexander, primary, Řehák, Kamil, additional, Prokop, Aleš, additional, and Ranjan, Vinayak, additional
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- 2020
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20. Determination of static transmission error of helical gears using finite element analysis
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Czakó, Alexander, Řehák, Kamil, Prokop, Aleš, Ranjan, Vinayak, Czakó, Alexander, Řehák, Kamil, Prokop, Aleš, and Ranjan, Vinayak
- Abstract
2-WP07-005 (TN01000026/2-V18) - At present, increasing emphasis is being placed on low noise levels, especially in the automotive industry. One of the dominant sources of noise (and vibration) in vehicles (with an electric motor as well as an internal combustion engine) is the transmission system. In order to effectively reduce vibration and noise of gears and transmission systems, some important gear parameters should be determined / measured. One of these parameters is the static transmission error, which is addressed in this article. The evaluated parameter is the peak-to-peak value of the transmission error, which appears to be closely related to NVH (Noise Vibration and Harshness). The transmission error depends, inter alia, on the tooth macrogeometry (expressed by the contact ratio) and the tooth microgeometry (intentional tooth modifications), the influence of both has been analyzed and is presented in this article. The transmission error can be determined by virtual measurement (computationally) in software enabling finite element analysis or by technical experiments on a test rig. The results in this paper are based on the outputs of numerical simulations using the finite element method. This approach can be used at developing phase to find the optimal solution and to save a lot of time. In addition, no physical components are required and a wide range of arbitrary gear configurations can be analyzed. Nevertheless, the technical experiment is still necessary, thus the test rig will be designed/constructed in the near future, including the possibility of lubrication. The results will then be compared with numerical simulations.
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- 2020
21. Investigating the influence of computational model complexity on noise and vibration modeling of powertrain
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Novotný, Pavel, Prokop, Aleš, Zubík, Martin, and Řehák, Kamil
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noise ,contacts ,lcsh:Mechanical engineering and machinery ,nonlinearity ,lcsh:TJ1-1570 ,dynamics ,structure ,vibration ,transient numerical algorithms - Abstract
The paper presents advanced computational models suitable for the development of a modern powertrain in the field of noise and vibration. The aim is to decide how detailed the model should be to correctly describe the vibrational and acoustic performance of the powertrain. In general, the advanced computational model of the powertrain – a virtual powertrain – is developed as a powerful tool for the solution of structural and also thermal and fatigue problems. Main results from the field of vibrations are verified by technical experiments using laser vibration technique and strain gauges. Afterwards, the simpler computational models are compared with the virtual powertrain and the results are discussed. The virtual powertrain is assembled, as well as numerically solved, in Multi Body System extended by user written subroutines. The virtual engine results are validated by measurements performed on compression ignition in-line six-cylinder engine.
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- 2016
22. Experimental verification of the power required for the movement of the tracked vehicle
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Jonák, Martin, primary, Hloušek, David, additional, and Řehák, Kamil, additional
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- 2018
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23. Transmission error analysis for heavy-duty gearbox
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Kučera, Pavel, primary, Píštěk, Václav, additional, Prokop, Aleš, additional, and Řehák, Kamil, additional
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- 2018
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24. Determination of the modal parameters on the thin flat structures
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Zajac, Roman, primary, Prokop, Aleš, additional, and Řehák, Kamil, additional
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- 2018
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25. Parameter effecting the experimental determination of modal properties
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Řehák, Kamil, Kučera, Pavel, Prokop, Aleš, Řehák, Kamil, Kučera, Pavel, and Prokop, Aleš
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The investigation of structure dynamic behavior can be done by finding modal properties, which are based on the relation of force and vibration response. The information about exact force value is in most application unknown, but the investigation can be done for unit magnitude of force. In case of using modal exciter, the force applied to structure is transferred by connection between modal exciter and structure. The stiffness of connection part can affect the dynamic behavior and change the modal properties, or response of investigated part, because of additional modal properties of connection part. This article is focused on the influence of two different rod stiffness during modal properties identification. The modal exciter is used to find potential critical frequency during decreasing frequency. The affect is evaluated on the surface normal velocity as well as acoustic pressure. The stiffness of rod significantly affects the dynamic response of structure and based on that can add frequency, when the emitted noise is high.
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- 2018
26. Heavy-Duty Transmission Gear Shift Investigation by Virtual Prototypes
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Prokop, Aleš, Kučera, Pavel, Řehák, Kamil, Prokop, Aleš, Kučera, Pavel, and Řehák, Kamil
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This paper deals with application of virtual prototype to the heavy-duty vehicles gearbox concept. Used methodology was developed and validated on the single stage gearbox concept. Afterwards the virtual prototype was applied to complex gearbox and extended for gear shift. Gear shift has a significant influence on comfort of vehicle and also for its lifetime. The gear shift process has to be fast and smooth as much as possible, which is very difficult. This paper deals with using virtual prototype to see the effect of different gear shift process on the vibration of gearbox. The validation by the experimental approach of gearshift has not been performed yet.
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- 2018
27. Transmission error analysis for heavy-duty gearbox
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Kučera, Pavel, Píštěk, Václav, Prokop, Aleš, Řehák, Kamil, Kučera, Pavel, Píštěk, Václav, Prokop, Aleš, and Řehák, Kamil
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This paper deals with an analysis of the transmission error. For this purpose, the measuring loop was assembled from two gear boxes. Subsequently, angles, torque and shaft speed were set or measured. For the evaluation a calculation method was used and the impact of the different transmitted torque was evaluated. The measuring loop enables to test at different operation conditions of torque and shaft rotation direction. In this paper, the static transmission error analysis for braking mode at 50 rpm shaft speed and torque range from 600 to 2400 Nm is described.
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- 2018
28. Experimental verification of the power required for the movement of the tracked vehicle
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Jonák, Martin, Hloušek, David, Řehák, Kamil, Jonák, Martin, Hloušek, David, and Řehák, Kamil
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This article deals with the experimental verification of the power requirements of the tracked vehicle power unit while driving on a flat terrain. Requirements are based on results of a dynamic simulation. At first, the article presents the description of the simulation model, including the virtual terrain, on which the vehicle was moved. Second, a description of the experiment performed directly on the real prototype is presented. Measured variables were flow rates and pressures in the hydraulic system, whereby the power transmission from the engine to drive sprockets of four tracked undercarriages is ensured. Finally, there is the comparison of the calculated and measured time-power characteristics. The results correspond to each other.
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- 2018
29. Determination of the modal parameters on the thin flat structures
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Zajac, Roman, Prokop, Aleš, Řehák, Kamil, Zajac, Roman, Prokop, Aleš, and Řehák, Kamil
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This paper presents the investigation of modal parameters using the different approaches. The object of the examination is the simple structure such as flat rectangle plate is. Before starting the measurement, there have been calculated natural frequencies of the plate by analytical approach. Subsequently, the experiment part is performed. The appropriate measuring apparatus has to be applicated for the experimental analysis. First, there are evaluated modal parameters of the specimen, the so-called “frequency sweep” is used as the input signal for excitation. After that, the experimental harmonic analysis is performed according the obtained eigen frequencies from the modal analysis. In the final stage, the data from simulations and experimental measurement are compared.
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- 2018
30. Effective computational model for a solution of turbocharger rotor dynamics
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Novotny, Pavel, primary, Dlugoš, Jozef, additional, Prokop, Aleš, additional, Řehák, Kamil, additional, and Raffai, Peter, additional
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- 2017
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31. Effective computational model for a solution of turbocharger rotor dynamics
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Novotny, Pavel, Dlugoš, Jozef, Prokop, Aleš, Řehák, Kamil, Raffai, Peter, Novotny, Pavel, Dlugoš, Jozef, Prokop, Aleš, Řehák, Kamil, and Raffai, Peter
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The article describes the development and a subsequent application of a computational model for effective and fast simulations of the turbocharger rotordynamics in time domains. The simulation tool consists of two basic models which are described in the article. The rotor is modelled as a flexible structure based on the nonlinear beam approach suitable for an effective solution in the time domain. The computational model also incorporates radial and axial bearing models. Theoretical background of the inovative journal bearing computational models, based on the numerical solution of the Reynolds equation, is presented. The capabilities of the simulation and sample results are demonstrated on a middle size turbocharger rotor supported by fully floating ring bearings.
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- 2017
32. Complex strategy for a development of highly elastic couplings
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Novotny, Pavel, Kocián, Ivan, Prokop, Aleš, Řehák, Kamil, Novotny, Pavel, Kocián, Ivan, Prokop, Aleš, and Řehák, Kamil
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This paper presents complex strategy for a development of highly elastic couplings. There are presented methods how to determine the dynamics characteristic of the coupling. The highly elastic coupling is applied to the connection of an in-line six-cylinder natural gas engine and an electrical generator. Loading forces are applied based on the values of combustion pressures measured in an engine cylinder. Experimental verification of the computational model results was carried out by measuring the values on a testing engine using non-contact laser measuring technique.
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- 2016
33. Micro-CT Based Imaging and Numerical Analysis of Bone Healing
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Řehák, Kamil, primary and Skallerud, Bjørn, additional
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- 2014
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34. Study of Straight and Oblique Mandible Fracture Behavior in the Chin Section
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Valášek, Jiří, primary, Ebringerová, Veronika, additional, Řehák, Kamil, additional, Krpalek, David, additional, and Florian, Zdeněk, additional
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- 2012
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35. Comparative Study of Mechanical Properties of Bone Tissue Based on the CT and the µCT Slices
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Prášilová, Eva, primary, Marcián, Petr, additional, Krpalek, David, additional, Řehák, Kamil, additional, Malina, Radomír, additional, and Konečná, Veronika, additional
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- 2012
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36. Finite Element Analysis of Mandible Reconstruction Plate in the Case of Symphysis Fracture
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Valášek, Jiří, primary, Řehák, Kamil, additional, Krpalek, David, additional, Ebringerová, Veronika, additional, and Florian, Zdeněk, additional
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- 2012
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37. Numerická simulace proudění oleje v převodové skříni
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Řehák, Kamil, Prokop, Aleš, Činčár, Vojtěch, Řehák, Kamil, Prokop, Aleš, and Činčár, Vojtěch
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Návrh komponent, následné ověření funkčnosti a případné optimalizace jsou nedílnou součástí jakéhokoliv výrobního procesu. Na základě zvyšujících se požadavků zákazníků je snahou dosáhnout co nejmenších rozměrů a nejnižší ceny, a to při zachování bezpečnosti. Začlenění obou hledisek je možné docílit pomocí pokročilých výpočtových přístupů, přičemž tato práce je zaměřena na oblast simulace proudění. Konkrétně se zabývá analýzou prouděním oleje v převodové skříni kolejového vozidla pomocí výpočetní dynamiky tekutin neboli CFD. Simulace proudění byly realizovány prostřednictvím softwaru ParticleWorks, který pracuje se semi-implicitní metodou pohyblivých částic MPS, jehož vhodnost se ověřila na krátkých rozborových pracích. Sledováním proudění v pracovním prostoru byla nejprve ověřena geometrie převodové skříně. Kritické jsou však oblasti ložisek, jejichž kvalita mazání byla analyzována pomocí řady výpočetních modelů, které zahrnovaly rozdílné provozní podmínky, jež mohou nastat. V závěru práce je mimo shrnutí celkového vyhodnocení, také nastíněn možný návrh na potenciálního zlepšení distribuce a kvality mazání ložisek., Component design, subsequent functional verification and possible optimization are an integral part of any production process. Based on increasing customer requirements, the aim is to achieve the smallest possible dimensions and the lowest possible price, while maintaining safety. Incorporating both aspects can be achieved using advanced computational approaches, while this work focuses on the area of flow simulation. Specifically, it deals with the analysis of oil flow in a railway vehicle gearbox using computational fluid dynamics or CFD. The flow simulations were performed using ParticleWorks software, which works with the semi-implicit moving particle method MPS, whose suitability was verified by short analysis works. By monitoring the flow in the workspace, the geometry of the gearbox housing was first verified. However, the critical areas are the bearings whose lubrication quality was analysed using a series of computational models that included the service conditions that may occur. In addition to summarizing the overall evaluation, the paper concludes by outlining a possible suggestion for the potential improvement of bearing distribution and lubrication quality.
38. Filtry pevných částic pro vznětové motory
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Dundálek, Radim, Řehák, Kamil, Hanák, Jiří, Dundálek, Radim, Řehák, Kamil, and Hanák, Jiří
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Bakalářská práce popisuje vznik škodlivých částic při spalovacím cyklu vznětového motoru a zamezení jejich šíření do ovzduší pomocí filtrů pevných částic. První část práce se zabývá typy a mechanismy vzniku těchto částic včetně regulace jejich maximálních hodnot prostřednictvím emisních norem. Práce následně shrnuje princip fungování filtrů pevných částic, jejich druhy, způsoby konstrukce a jejich regenerace. Popisuje také konkrétní systémy dieselového motoru s filtrem pevných částic, a to včetně praktických řešení. V závěru se práce věnuje nejvíce problematickým kombinacím filtru pevných částic s dieselovým motorem a nastiňuje možný budoucí technologický vývoj., 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.
39. Deformační analýza přímých nosníků s vlivem posunutí podpor
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Navrátil, Petr, Řehák, Kamil, Štourač, Vít, Navrátil, Petr, Řehák, Kamil, and Štourač, Vít
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Tato práce je zaměřena na řešení přímých staticky neurčitě uložených nosníků a vlivu posunutí jejich podpor na výsledné řešení. K řešení bylo použito metod Castiglianovy věty, diferenciální rovnice ohybové čáry a nosníku s vnitřními klouby (Gerberův nosník). Jako příklad byl zvolen nosník o dvou polích a třech podporách, zatížený po celé jeho délce liniovým zatížením., These work is focused on the solutions to straight beams statically stored indefinitely and the influence of displacement their support to the final solution. The solution was used Castigliano’s theorem, fluxional equation of bend line methods and beam with internal joints (Gerber beam). As an example, he was elected the two boxes - beam about three supports loaded for the entire length of a line load.
40. Konstrukční návrh řadicího mechanismu, určeného pro elektromobily
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Prokop, Aleš, Řehák, Kamil, Capoušek, Josef, Prokop, Aleš, Řehák, Kamil, and Capoušek, Josef
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V této diplomové práci je řešena problematika návrhu mechanismu řazení vícestupňové převodovky elektromobilu. Rešerše je zaměřena na současný vývoj elektrického pohonu vozidel a možností aplikací vícestupňových převodovek. Dostupné studie ukazují potenciální zlepšení parametrů vozidel, zejména snížení spotřeby energie a prodloužení dojezdu. Návrh mechanismu zahrnuje vytvoření koncepčních návrhů, volbu optimální varianty na základě vícekriteriálního hodnocení, konstrukční návrh a následnou analýzu komponent a vypracování výkresové dokumentace vybraných součástí., In this paper the problematic of the design of the shift mechanism for a multi-gear transmission is presented. Research part is focused on the recent electric drive units development and the application possibilities of multi-gear transmissions. Available studies shows a possible improvement in vehicle parameters, primarily a reduction in energy consumption and vehicle drive range. Design of the shift fork mechanism includes the conceptual design creation, the optimal variant choice based on a multi-criteria assessment, the structural design and the subsequent analysis of components and creation of a technical drawing of selected parts.
41. Konstrukční návrh prototypové stolní navíječky lineárních cívek
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Řehák, Kamil, Hrabčík, Miroslav, Ryza, Vojtěch, Řehák, Kamil, Hrabčík, Miroslav, and Ryza, Vojtěch
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Tato diplomová práce se zabývá konstrukčním návrhem prototypové stolní navíječky lineárních cívek. V první části této práce jsou popsány základní vlastnosti cívky a metody jejího navíjení. V následující části byla provedena kritická rešerše dostupných navíječek na trhu na základě, které byl vytvořen samotný koncept navíječky. V práci je detailně popsán postup návrhu samotné navíječky spolu s konstrukčními variantami jednotlivých částí navíječky. Závěrem práce je prezentován dosažený koncept prototypové navíječky. Tato problematika byla řešena pomocí 3D programu SolidWorks a MKP v programu ANSYS Student. Celá práce popisuje jednotlivé kroky pro návrh samotného konceptu prototypové lineární navíječky a konstrukční řešení základních komponent., The diploma thesis deals with the design of a prototype table winder for linear coils. The first part of this work describes the basic properties of the coil and its winding methods. In the following section, a critical search was made of the reels available on the market based on which the reel concept itself was created. The work describes in detail the procedure of the winder design together with the design variants of the individual parts of the winders. At the end of the diploma thesis is presented the needed prototype of the coil winder. This problem was solved by using the 3D program SolidWorks and FEM in the program ANSYS Student. The project describes the individual steps of the design of the concept of a prototype linear winder and the component's design.
42. Vibrace rovinných desek
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Prokop, Aleš, Řehák, Kamil, Zajac, Roman, Prokop, Aleš, Řehák, Kamil, and Zajac, Roman
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Táto diplomová práca je zameraná na problematiku vibrácií rovinných dosiek. Obsahuje výpočtové a experimentálne prístupy využívané pri stanovení vlastných tvarov a vlastných frekvencií rovinných dosiek. V tomto dokumente sú vzájomne porovnávané analytické, numerické a experimentálne výsledky modálnej analýzy výhradne voľného uloženia obdĺžnikovej rovinnej dosky. V práci je taktiež zahrnuté vynútené kmitanie s harmonickým budením, ako nadväznosť na získané výsledky z modálnej analýzy., The diploma thesis is focused on vibration of the planar plates. It includes the computational and experimental approaches used to determine the mode shapes and frequencies (eigenvalues) of planar plates. This paper compares the analytical, numerical and experimental results of the modal analysis specifically the free-standing rectangular planar plate. The work also encompasses forced oscillation with harmonious excitement as a continuation of the obtained results from modal analysis.
43. Užití převodových ústrojí u elektromobilů
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Řehák, Kamil, Prokop, Aleš, Běloušek, Ondřej, Řehák, Kamil, Prokop, Aleš, and Běloušek, Ondřej
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Bakalářská práce nejprve rozděluje elektromobily podle jednotlivých koncepcí, přičemž cílem je přiblížit a popsat charakteristické prvky, kterými se liší od konvenčních vozů a jenž jsou v různých typech elektromobilů užity. Z podstaty elektromobilu je zřejmé, že elektrická energie potřebná k pohonu musí být vhodným způsobem skladována, a proto je část práce zaměřena na baterie a komponenty k takovémuto pohonu potřebné. Pohonný trakt elektromobilů, jenž je dále popisován, se liší v závislosti na přítomnosti či absenci spalovací jednotky a míře jejího příspěvku k pohonu vozu. Společným znakem je elektromotor, který mění elektrickou energii na mechanickou, a bez kterého by pohonný trakt nebyl kompletní. Využité převodovky v elektromobilech jsou ovlivněny typem pohonné jednotky, se kterou mají být v součinnosti, a proto je z každé skupiny vybráno jedno ústrojí. Zástupcem hybridů je planetové převodové ústrojí vozu Toyota Prius 2010, čistě bateriové vozy jsou zastoupeny jednostupňovou převodovkou společnosti Tesla a zmíněny jsou vícestupňové převodovky udávající trend v této oblasti. Vzhledem k absenci spalovacího motoru u některých typů se do popředí, co se hluku a vibrací týče, dostávají převodová ústrojí, u kterých je hlavním zdrojem vibrací záběr ozubených kol a řinčení dalších komponent převodovky. Těžištěm poslední části práce je návrh technického experimentu pro měření vibrací a hluku od dvoustupňové automatické převodovky, kterému předchází teoretický základ věnující se měření těchto nežádoucích projevů. Samotný návrh bere ohled na vhodnost měřicí aparatury, správnou volbu komponent realizující uzavřenou smyčku a také na zástavbový prostor akustické komory., 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.
44. Hybridní pohony v konstrukci traktorů
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Prokop, Aleš, Řehák, Kamil, Líčeník, Adam, Prokop, Aleš, Řehák, Kamil, and Líčeník, Adam
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Tato bakalářská práce zpracovává přehled typů hybridních pohonů v konstrukci traktorů. Zhodnocuje jejich funkční výhody i nevýhody a uvádí příklady některých traktorů a jejich součástí. Zaměřuje se na komponenty používané v hybridních pohonech. V závěru jsou zhodnoceny jednotlivé varianty z hlediska emisí a ekonomičnosti provozu., This bachelor’s thesis utilizes survey of types hybrid propulsion systems in the tractor construction. It evaluates its operational advantages and disadvantages and presents examples of some tractors and its elements. The thesis focuses on components which are used in hybrid propulsion systems. In the conclusion there is a review of individual variations in terms of emission and economy of operation.
45. Větrné elektrárny
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Řehák, Kamil, Prokop, Aleš, Šponiarová, Petra, Řehák, Kamil, Prokop, Aleš, and Šponiarová, Petra
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Výroba elektrické energie z obnovitelných zdrojů je velmi aktuálním tématem. Do této oblasti patří také výroba elektrické energie pomocí větrných elektráren, kterými se zabývá tato bakalářská práce. Za účelem vytvoření přehledu typů větrných elektráren byla provedena rozsáhlá rešeršní studie. Z hlediska využívání větrných elektráren v obydlených územích je velmi diskutovaným tématem kromě vizuálního efektu i oblast vibrací a hluku, na kterou má zásadní vliv konstrukce větrné elektrárny. Pro stanovení ovlivnění člověka větrnými elektrárnami jsou prováděny technické experimenty, které se řídí jednotlivými normami a doporučeními. V rámci práce je za účelem posouzení hluku a vibrací větrné elektrárny navržen technický experiment, který využívá rozdílné přístupy z důvodu stanovení kritických komponent. Součástí návrhu je výběr vhodné měřicí techniky a volba místa pro její následné použití. Závěrem je využívání větrných elektráren kriticky posouzeno., The electricity production from renewable sources is a very current topic. It also includes the electricity made by wind power plants, which the bachelor’s thesis concentrates on. An extensive research study was conducted to provide an overview of wind turbine types. Concerning wind power plants, apart from their visual impact, noise and vibration connected to their operating is an often discussed issue. The construction of a wind turbine stands for the most important role in reducing such unwanted effects. Technical experiments following specific standards and recommendations are performed to assess the impact of wind turbines-emitted noise and vibration on humans. In order to assess noise and vibration of a wind turbine a technical experiment is proposed, which uses different approaches to determine the critical components. The selection of a suitable measuring equipment and the choice of location for its subsequent use are important parts of the design. At last, the use of wind power plants is critically reviewed.
46. Válce čtyřdobých spalovacích motorů
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Dlugoš, Jozef, Řehák, Kamil, Vanda, Marek, Dlugoš, Jozef, Řehák, Kamil, and Vanda, Marek
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Tématem této bakalářské práce jsou pracovní válce čtyřdobých pístových spalovacích motorů. První část práce obecně popisuje princip čtyřdobého pracovního cyklu, konstrukci zážehových a vznětových motorů. Další části jsou zaměřeny na popis funkcí a požadavků pracovních válců. Uveden je také vliv válců na samotný chod motoru a jeho životnost. Dále je pozornost zaměřena na jednotlivé způsoby konstrukce válců, materiály a jejich použití v minulosti a dnes., The topic of this bachelor thesis is Cylinders of Four-stroke Engines. First part is about four-stroke cycle, engine construction. Next parts are about cylinders, their function and requirements. Also included is the importance of the cylinders on the engine operation and engine life. Last part is focused on the construction, materials of the cylinders and their usage in the past and today.
47. Filtry pevných částic pro zážehové pohonné jednotky
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Dundálek, Radim, Řehák, Kamil, Vyhnálek, David, Dundálek, Radim, Řehák, Kamil, and Vyhnálek, David
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Tato bakalářská práce pojednává o filtrech pevných částic pro zážehové pohonné jednotky a klade si za cíl shrnout současný stav poznání a budoucí prospekt této problematiky. V první části se práce zabývá technologií přímého vstřikování benzínu, neboť tato technologie zodpovídá za zvýšenou tvorbu pevných částic, kterým je také věnována pozornost, stejně tak i ostatním škodlivinám. Dále se zde rozebírá důvod nutnosti využívání a dalšího vývoje filtrů, princip fungování a možnosti konstrukčního řešení včetně popisu jednotlivých součástí. Práce se také věnuje možným perspektivám budoucího vývoje přeplňovaných benzínových motorů s ohledem na splňování emisních norem., This bachelor thesis deals with gasoline particulate filters for spark ignition power trains and aims to summarize the current state of knowledge and prospects of this issue. The first part of the thesis focuses on gasoline direct injection technology as it is directly responsible for the increased formation of particulate matter, which is also subject of attention, including other pollutants. It also addresses the reason for the need of usage and further development of filters, the principle of operation and design options, including a description of the individual components. The thesis also discusses possible perspectives for the future development of turbocharged petrol engines with regards to meeting emission standards.
48. Planetové převodovky v konstrukci osobních a nákladních automobilů
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Prokop, Aleš, Řehák, Kamil, Novák, Petr, Prokop, Aleš, Řehák, Kamil, and Novák, Petr
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Práce se věnuje užití planetových převodů v samočinných převodovkách pro osobní a nákladní vozy. Převodovou část tvoří často ustálené soukolí Simpson a Ravigneaux. Je zde proto proveden jejich kinematický rozbor. Kompletní popis samočinné převodovky vysvětluje podrobně princip funkce převodovky jako celku. Dále je práce členěna na dvě části – převodovky pro osobní a nákladní vozy. Je provedena rešerše, popsány hlavní charakteristiky dané skupiny a detailněji rozebrán jejich zástupce. V poslední části je proveden kinematický a silový rozbor převodovky ZF – Ecomat 6HP 602., The thesis deals with the use of planetary gears in automatic transmissions for cars and trucks. The transmission part consists of Simpson and Ravigneaux gears. Therefore, their kinematic analysis is performed here. A complete description of the automatic gearbox explains in detail the principle of the function of the gearbox as a whole. Furthermore, the work is divided into two parts - gearboxes for cars and trucks. A research is carried out, the main characteristics of the group are described and their representative is discussed in detail. In the last part the kinematic and force analysis of ZF - Ecomat 6HP 602 gearbox is carried out.
49. Konstrukční návrh zubové spojky pro aplikaci v kolejové dopravě
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Prokop, Aleš, Řehák, Kamil, Pelíšek, Vojtěch, Prokop, Aleš, Řehák, Kamil, and Pelíšek, Vojtěch
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Cílem této práce bylo vytvořit konstrukční návrh zubové spojky pro aplikaci v kolejové dopravě. Práce předkládá ucelený pohled na tuto problematiku. Nejprve je proveden krátký teoretický úvod do dané problematiky. Následuje praktická část, kde je podrobně popsána konstrukce celé spojky a zejména nově navržená řešení. Provedené pevnostní výpočty se zabývají klíčovými komponenty, které jsou nezbytné pro zajištění bezpečného provozu. Tyto výpočty je možné aplikovat nejenom pro tento konkrétní případ, ale i na zubové spojky odlišných konstrukcí, jelikož v principu se tyto výpočty příliš neliší. V poslední kapitole, která se zabývá dynamickým modelem, jsou ověřeny veškeré teoretické předpoklady, zejména pohyby spojky a na ni působící zatížení. Pokud se tedy čtenář zabývá problematikou zubových spojek, a to nejenom v železničním průmyslu, předkládá tato práce ucelený pohled na tuto součást. Navržená spojka a veškeré provedené simulace jsou reálně využitelné v provozu., The aim of this work was to create a design of a gear coupling for railway vehicle application. The work presents a comprehensive view of this issue. First of all, a brief theoretical introduction to the issue is made. The practical part follows, where the design of the whole coupling and especially the newly designed solutions are described in detail. The strength analysis performed deal with the key components that are necessary to ensure safe operation. These analyses can be applied not only for this particular case, but also to gear couplings of different designs, because in principle these calculations do not differ much. In the last chapter, which deals with the dynamic model, all the theoretical assumptions are verified, especially the coupling movements and the applied loads. If the reader deals with the issue of gear couplings, not only in the railway industry, this work presents a comprehensive view of this component. The designed coupling and all performed simulations are really usable in operation.
50. Napjatostní analýza v nalisovaném spoji
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Horníková, Jana, Řehák, Kamil, Dudek, Milan, Horníková, Jana, Řehák, Kamil, and Dudek, Milan
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Práce je zaměřena na stanovení přesahu při lisování v závislosti na mezním stavu pružnosti materiálu pomocí analytických metod Pružnosti a pevnosti. Vypočtené hodnoty jsou ve formě změněného technologického postupu uvedeny do výroby v přesnosti umožňující dostupné technologie. Je provedeno i stručné ekonomické zhodnocení změny technologického postupu., This thesis is focused on calculation of overlap in press fit depending on vield strength. There are used methods of analytic elasticity. The counted values are implemented into the technologic process as updated technologic specification. The practical values of overlap depend on exactness of available technology. The evaluation is done at the end of thesis (economic evaluation as well)
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