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Engagement Force Control of Multi-plate Clutches of Dual Clutch Gearbox
Horák, Josef ; Prokop, Aleš (referee) ; Novotný, Pavel (advisor)
The master’s thesis deals with ways of controlling starting clutches of cars, especially of DQ200 gearbox, which contains dry disc clutches. The introduction describes basic principles of torque transfer and amount of clutch force. Then the description of construction of starting clutches and ways of controlling clutch types mentioned beforehand is given. In the next part of the thesis, wide spectrum of control methods is measured, from which a certain part is selected. This is followed by driving tests and based on driving data, one method of the clutch control is chosen. Then those control methods from narrow selection are tested for acoustic impact in the cabin of the car. In the end the best way of clutch control is selected. The selection based on driving data and acoustic measurement.
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The influence of the chassis to the power and performance characteristics of tractors
Rašovská, Hana ; Slimařík, Dušan (referee) ; Bauer, František (advisor)
This master thesis deals with the influence of the type of tractor chassis on its utility properties. For the rating were used tractors John Deere 8 – series with wheel and track chassis, equipped with the same engine and gearbox, which were carried out for laboratory and field tests. The aim of laboratory tests was the exclusion of the difference in engine power of both tractors and the aim of field tests was to evaluate the drawbar properties of tractors with a different type of chassis. The reference parameter was especially drawbar pull, further drawbar power, slip and fuel consumption. Based on the tabular and graphical elaboration of the measured values were evaluated results.
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The effect of tyres on the output parameters of tractors
Kopečný, Aleš ; Havlíček, Miroslav (referee) ; Bauer, František (advisor)
The thesis summarizes the results of the measurement of the output parameters of the tractor, on which were mounted three different types of tires. The measured parameters are the maximum pulling power, slippage, specific effective fuel consumption at the maximum pulling performance. The final measured and calculated results are presented in tables and graphs. The results of the measurements were processed by the use of regressive analysis.
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Effect of surface texturing on elastohydrodynamic films
Puchner, Jiří ; Dzimko, Marián (referee) ; Křupka, Ivan (advisor)
Diploma thesis describes analysis of influence of surface texturing on non-conformal rubbing surfaces. High speed camera was used to observe the effect of micro-dents of various depths on film thickness under pure rolling and rolling/sliding conditions. It can be concluded from the obtained results that micro-texture of suitable sizes can results in film thickness increase without lubrication film breakdown.
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The influence of the chassis on drawbar properties of tractors
Chmelař, Zdeněk ; Havlíček, Miroslav (referee) ; Bauer, František (advisor)
In this master thesis is analyzed the current situation in the construction chassis of tractors, in addition, a methodology for evaluating the impact of influences on drawbar properties of tractors. The main objective of this work was to analyze and conclude the measured drawbar properties of selected tractor same power and weight categories with different chassis designs. Measured and calculated values were tabular and graphically presented. When evaluating the drawbar properties were determined according tractive power and slip depending on the drawbar forces.
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Vliv síly v horním táhle závěsu traktoru na spotřebu a výkonnost souprav na zpracování půdy
Drašar, Jan
The aim of the thesis was to analyze the measured values from measurements. In the research part of the work, an overview of the technologies used for soil processing was processed. Here are the basic tillage systems (conventional tillage, conservation tillage and direct seeding). Soil processing technologies such as ploughing, mulching, strip processing or loosening without turning topsoil are also summarized here. In the final part, the machines used for tillage were described. The methodology described the measuring devices and individual plowing sets that were used to measure the output data of the plowing sets. When evaluating the data, the main parameters were the specific effective fuel consumption, specific effective efficiency, hectare effective efficiency and slippage of the drive wheels depending on the force in the upper link and the pressure in the traction cylinder of the selected tractor sets. The diploma thesis was prepared from 3 field measurements, a total of 71 measurements were made. Individual measurements were analyzed and it was shown that the length of the upper drawbar increases the average specific efficiency by 17%, the hectare effective efficiency by 20%. Furthermore, it has been shown that the average consumption will decrease by 6% and the increase will decrease from 2% to 7.5% on average.
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Vliv huštění pneumatik na spotřebu paliva a výkonnost traktorové soupravy
Čuba, Norbert
The bachelor thesis deals with the influence of tractor tyre inflation on fuel consumption, slip and tractor performance in off-road conditions. It focuses on machine output parameters such as tire slip and hourly fuel consumption. The actual measurement of these parameters was carried out at three different tire pressures and keeping the tillage depth constant. The result of the field measurements is a confirmation of the fact that lower tyre pressures result in lower wheel slip and, at the same time, lower machine fuel consumption. These results are tabulated and graphically presented.
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Analýza výstupních parametrů traktorové soupravy na zpracování půdy v podmínkách soukromé farmy
Kokeš, Matěj
The thesis describes the current state in the design of soil processing machines and evaluates the influence of the three-point hitch settings of the tractor and the working tool on the output parameters of the sets. As part of the work, experimental measurements were carried out on two sets with a trailed cultivator and a trailed plow. The first set examined the effect of the load on the front axle and engine speed on tractor performance, while the second set examined the effect of the force in the upper hitch, loading of the driving axles, and engine speed on the output parameters of the tractor. The results of both measurements showed that with the correct tractor settings, slippage and fuel consumption decrease, leading to increased performance and work efficiency.
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Analysis of dynamic strength of friction knots used in military climbing
Telvák, Radek ; Michalička, Vladimír (advisor) ; Braum, Zdeněk (referee)
Title: Analysis of dynamic strength of friction knots used in military climbing Objectives: The aim of this work is to determine the resulting impact force generated by selected friction systems at different values of the fall factor. To calculate what maximum values of auxiliary Reep cord length and maximum load weight can be achieved without system failure. Determine the correlation between the magnitude of the impact force and the slip length. Methods: This thesis describes an experiment in which the resulting impact force acting on a friction system at different drop factors was determined. A 6mm Reep cord and an 11mm rope and friction knots used in military climbing techniques were selected for analysis. Testing was carried out in a polygon on a drop tower. Each of the friction knots was subjected to 5 tests at the same fall factor. The individual knots were statistically compared with each other in terms of impact force and slip. Using direct proportionality, the maximum possible values of the auxiliary Reep cord length and the weight of the load were determined. A correlation analysis was used to establish a correlation between impact force and slip. Results: It was found that at all measured values of the fall factor, the Twist prusik achieved the lowest values of the resulting impact force...
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Static strength analysis of friction knots used in military climbing
Telvák, Radek ; Michalička, Vladimír (advisor) ; Baláš, Jiří (referee)
Title: Analysis of static strength of friction knots used in military climbing. Objectives: Strength determination of selected knots on static ropes under static load. Methods: This bachelor thesis shows a laboratory experiment, where the influence of friction knots on the strength of the Reep cord tied to a static rope under static load was determined. For the purposes, a 6mm Reep cord and 10.5mm rope and friction knots used in military climbing techniques were selected. The experiment was run on a vertical test rig. Each of the selected knots was tested 10 times. Every knot was compared among the others in the first slip, slip length, maximum strength, nominal strength drop and the point of failure. Results: The highest average values of the first slip and the maximum strength were achieved by the Twist prusik. The lowest value of the slip length was measured at the Blake friction knot. Compared to other of the selected knots, the lowest decrease in nominal strength by 14 % was found on the Blake knot, while the highest decrease in nominal strength is found in the Twist prusik. The Reep Cord failed in 81 % of all attempts. Keywords: military climbing, friction knot, knot strength, slip, point of failure, nominal strength
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