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Valvetrain of Compression-ignition Tractor Engine
Mikula, Vojtěch ; Janoušek, Michal (referee) ; Drápal, Lubomír (advisor)
This bachelor thesis deals with the main types and parts of the valvetrain systems of four-stroke engines. In the first part of the thesis are presented the most widely used versions of valvetrains and their use in the tractor engines. In the next part of the thesis is performed the construction and stress calculation of the valvetrain according to proposed proportions.
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Valvetrain of Compression-ignition Tractor Engine
Mikula, Vojtěch ; Janoušek, Michal (referee) ; Drápal, Lubomír (advisor)
This bachelor thesis deals with the main types and parts of the valvetrain systems of four-stroke engines. In the first part of the thesis are presented the most widely used versions of valvetrains and their use in the tractor engines. In the next part of the thesis is performed the construction and stress calculation of the valvetrain according to proposed proportions.
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Valvetrains of four stroke combustion engines
Přeslička, Jaroslav ; Novotný, Pavel (referee) ; Píštěk, Václav (advisor)
The thesis deals with technical solutions of four stroke piston engines valvetrains, their advantages and disadvantages. First it describes four stroke engine working cycle and outlines the problems of valvetrain timing. Then follows the description of valve design, camshafts, types of cams and valve lift course. Another part of the text occupies with SV, OHV, OHC and unconventional valvetrains. The following part is focused to the ways of camshaft drive. The last part is engaged in variable valvetrains. At the end there is indicated the future of combustion engines valvetrains.
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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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Chain Drive for Valvetrains
Vodička, Richard ; Píštěk, Václav (referee) ; Novotný, Pavel (advisor)
The objective of this bachelor‘s thesis is obtaining the general review about the way of driving valvetrains. Introduction is devoting the driving of distributive mechanism of combustion engines . The text of bachelor‘s thesis is splitted on three parts. The first part is explaining the principle of functioning enginetrain. Briefly are described individual assembling of ventil distributor of engines and its distinction depending on the way of its drive. The main attention is devoted to the chain drive of valvetrain, i.e. distinction of types chain drive, which are necessary for its correct functioning. And also, are described the main parts of valvetrain of the engine and the other possibilities of its driving. The second part of bachelor‘s thesis is comparising positives and negatives of chain drives of valvetrains with the othe one’s. In the third part of bachelor‘s thesis are presented the examples of application of the chain drives in the valvetrains in the four wheel drives machines, cars and motorcycles. In the conclusions is specified the contribution of the chain drive of valvetrains and evaluation of bachelor‘s thesis.
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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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