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Reduction of Valvetrain Mechanical Losses
Kučera, Pavel ; Píštěk, Václav (referee) ; Novotný, Pavel (advisor)
The topic of this thesis is the mechanical losses in the valvetrain. The purpose is to describe the creation of individual losses and their possible reduction. The main factor of creation of losses is friction. The result of this thesis is to highlight the possible methods to reduce friction and other influences acting on the valvetrain. The main benefit is description various types of surface and design modifications of valvetrains, which are already used or are in development.
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Gear Timing Mechanism for Valvetrains
Drdla, Adam ; Rasch, František (referee) ; Novotný, Pavel (advisor)
The objective of this thesis is to provide an overview of geared valvetrain. In introduction are described individual types of gears and their application in combustion engines. Then, the thesis is divided into three chapters. The first chapter provides a thorough analysis of geared valvetrain. Also, individual parts of valvetrain together with alternative methods of valve timing are briefly introduced. The chapter then follows to examine the working principle of gears, how forces and moments are transmitted, advantages of introducing helical gears instead of spur gears, different ways of gear manufacturing, gear material selection, heat treatment of gears and common gear failure mechanisms. The second chapter examines pros and cons of using geared valvetrains. The third chapter shows examples of how are geared valvetrains applied in tractors, trucks, ships, trains, cars and motorcycles. In the conclusion, the main advantages of using geared valvetrains are discussed and the whole thesis is summerized.
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Computational modeling of valvetrain mechanical losses
Mačuga, Martin ; Píštěk, Václav (referee) ; Novotný, Pavel (advisor)
The thesis disserts upon computational modelling of valve train mechanical losses, finding the appropriate method of solving and its application on valve gear in Diesel in-line four-cylinder engine. The thesis further disserts upon proposition of appropriate adjustments leading to the reduction of mechanical losses. The calculation was performed in MBS software ADAMS.
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Calculation of OHV-Valve Gear Dynamic Stress
Opluštil, Tomáš ; Kobský, David (referee) ; Rauscher, Jaroslav (advisor)
This diploma thesis deals with investigation of dynamic straining valve OHV for four-valve head diesel engine Zetor 1505 – 90 kW. The calculation is performed analytically in mathematic software MathCad and MBS software ADAMS/Engine 2005. Also in this diploma thesis is from results obtained from MBS system perfomed stressed analysis valve_rocker arm gear divorce method final elements (MKP) in program ANSYS 10.
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Parameters for 1D Single Cylinder Engine Simulation
Stryja, Štěpán ; Šebela, Kamil (referee) ; Janoušek, Michal (advisor)
The relationship between the 1D simulation and the corresponding input parameters is addressed in the paper. The one-dimensional simulation is demonstrated in the GT-Power environment. The work deals with both experimental and computational analysis of the input parameters. Additive methods of 3D printing of fixtures and subsequent measurement of volumetric flow rates on a Superflow Flowbench SF-260E purge station were used. This procedure led to the final calculation of discharge coefficients. The 3D scanning method, using ATOS 2M equipment, together with subsequent data processing, using the appropriate software, led to the analysis of the valvetrain mechanism and the construction of its kinematics. The practical part was demonstrated on two-cylinder heads of a four-stroke single cylinder engine with a displacement of 125 cm3, with natural aspiration. One of the heads was modified, resulting in volumetric flow increase of 29 % in case of the intake and 15 % in case of the exhaust, compared to the stock head. The work led to the acquisition of key input data for the 1D simulation of the aforementioned engine.
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Optimalizace časování ventilového rozvodu u přeplňovaného motoru
Mahr, Ivoš
This diploma thesis deals with optimization of timing valve train on turbocharged internal combustion engine. Experimental data was collected on engine dyno which belongs to the Institute of Engineering and Automobile Transport of Mendel University in Brno. Engine parameters were improved by changes in the timing of the intake and exhaust valves. Relation between the timing of the valves and characteristics of turbocharged engine with a turbocharger was researched. The results of this study make it possible to set the timing valve train according to the load of the internal combustion engine and thus reduce its consumption and increase performance.
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