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Vliv podvozku na tahové vlastnosti traktorů
Vykydal, Petr
The aim of this PhD thesis was to analysis laboratory and field measurements tractors with different chassis designs. For the measurements were used John Deere tractors with name 8320R if a wheel and if 8320RT crawler tractor, possessing the same engine power. Before the field measurements were conducted laboratory tests of tractors, which resulted was the compilation of the full speed characteristics. The field measurements were focused on identifying characteristics of tensile test tractors. For wheeled tractor were also measured differences tensile characteristics when changing inflation pressure. Subsequent comprehensive part of a field measurement looked at the analysis of data obtained from measurements of performance and energy parameters of tractor kits depending on the operating mode of the engine. From the experimental measurements show that the tractor equipped with a belt chassis design has a higher tensile strength and also has a lower specific consumption and slippage than wheeled tractor. When comparing the measured data with different wheeled tractor tire inflation pressure, we find that reducing inflation pressure has a positive effect on the change of the tensile characteristics. In the practical part of the measurements we have identified that tracked tractor achieves higher performance and lower energy intensity than the wheeled tractor. It was also shown that by adjusting the engine speed into so called economic areas can improve performance while reducing fuel consumption tractor sets.
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Analýza silových účinků pluhů na výstupní parametry orebních souprav
Slimařík, Dušan
The aim of this thesis is force effect analysis of ploughing rigs. MSC Adams software was used for mathematical-physical model drafting and subsequent evaluation of measured data from tensometrical load sensing. Designed model was utilized for force reactions calculations under the driving wheels of a tractor using analysis of spatial system of forces of tractors three point hitch. Field measurement data and data from MSC Adams software were tabular and graphically processed. Dependencies between plough and tractor connection setting and output performance of ploughing rigs were clarified. Results from experimental measurement with fully-mounted plough point out on the utilization of longitudinal and lateral position of ploughs CG for reducing of difference in load between furrow and land wheel with properly adjusted connection between plough and tractor. A result from experimental measurement with semi-mounted plough confirms the fact of significant difference in vertical load between rear axle wheels. This negative phenomenon could be eliminated with usage of traction cylinder localized in construction of semi-mounted ploughs over the horizontal joint. Correct adjustment of tractors three point hitch in case of fully-mounted ploughs and utilization of traction cylinder in case of semi-mounted ploughs have got positive influence on fuel consumption and field performance of ploughing rigs.
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Faktory ovlivňující ekonomiku traktorových souprav
Katrenčík, Jakub
Farm tractors are used in various works that is the reason why manufacturers equip the tractors with engines with outputs from 30 to 450 kW, mechanical or hydro mechanical gearboxes and tires with various acceptable inflation pressures and dimensions. Many types of tires which are available for agricultural tractors, places higher requests on the knowledge of the transfer of power from the tires on a surface. What is the impact of different design of tires transmission on output power or fuel consumption can be determined, for example, make a field measurements. Results of field measurement shows that tire inflation and type of tires has significant effect on pull performance slip and fuel consumption.
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Analysis of the Selected Firm
Krejčík, Václav ; Veselý, Petr (referee) ; Hanušová, Helena (advisor)
This diploma thesis is concerned with a comprehensive analysis of ZETOR TRACTORS a.s. company. The main goal and mission of the analysis is to depict an actual stage of the company by some procedures and methods from the financial statements and the strategy and financial analysis, and on the basis of these analysises suggest some solutions and recommendations, which could be the subject matter towards improvement of the current situation in the future.
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Tractors` Injection Systems Overwiev
Poláček, Milan ; Svída, David (referee) ; Dundálek, Radim (advisor)
The object of the bachelor’s thesis is to create an overview of injection systems at currently produced tractors. The first part of the overview is concerned with conceptions of diesel injection by tractors’ engines and with a description of its parts. There are also referred related technologies for power boosting. The second part is devoted to particular marks of tractors and used injection systems.
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Marketingová strategie prodeje traktorů Zetor na tuzemském trhu
Zmeková, Věra
The diploma thesis is about marketing strategy and selling Zetor tractors on domestic market. The aim was to find out the saleability of Zetor tractors in comparison with other imported brands -- New Holland and John Deere. Simultaneously state the position of ZETOR TRACTORS a.s. on domestic market in comparison with its competitors. It is significant that in the long term ZETOR TRACTORS a.s. is focused on manufacturing and selling tractors, which became pretty popular among customers. Due to low production costs there is a profitable ratio between price and performance. On the Czech market, the sales of Zetor tractors show the growing trend. During 2012 -- 2014 ZETOR TRACTORS a.s. increased its market share on domestic market by 10 %. ZETOR TRACTORS a.s. is the only producer of tractors in the Czech republic. The part of this thesis is a research of customer satisfaction with Zetor tractors and its purchase price. Based on customer opinions and the analysis of the financial situation of ZETOR TRACTORS a.s. a set of recommendations was given.
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