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Top of rail lubricant development
Skurka, Šimon ; Polach, Pavel (referee) ; Kvarda, Daniel (advisor)
Friction modification within the wheel-rail interface is an important way of achieving ecologically friendly transportation of both persons and goods. This thesis aims to develop a new TOR lubricant, which will be able to maintain suitable frictional conditions while securing minimal adhesion required for traction. All measurements were carried out on tribometer MTM in the ball-on-disc configuration. In the first step, individual components were examined. More complex compositions were measured after that and the three best of them were compared with commercial TOR lubricants. The results show a good ability of developed compositions to maintain required adhesion, reduce wear, and all of them had resistivity against over-lubrication. Lastly, the process of lubricant verification before its application in real traffic was discussed.
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Experimental study of friction modifiers in rail transportation
Knápek, Jiří ; Dzimko, Marián (referee) ; Galas, Radovan (advisor)
The adhesion in the wheel-rail contact can be effectively controlled by using the friction modifier. Adhesion control can reduce excessive wear of the contact bodies or noise. The essence of this diploma thesis is to determine the optimal amount of friction modifier in wheel-rail contact depending on the climatic and operating conditions. For experimental study of the behavior of the friction modifier, the twin-disc device is used. Twin-disc simulates and controls the most important operating parameters such as speed, slip, attack angle or contact pressure. On the basis of these findings, the off-board top-of-rail lubricator system was designed. This system controls the amount of friction modifier according to current climatic and operating conditions.
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An Experimental Research of Sanding in Wheel/Rail Contact
Machatka, Martin ; Hruška, Marek (referee) ; Omasta, Milan (advisor)
Presented master's thesis is focused on the experimental research of the sanding parameters in order to improve adhesion in the contact between wheel and rail. Sanding is the application of the sanding material directly in the wheel/rail contact. It is still common, most effective and traditional way how to deal with low adhesion problem, which is mainly caused by environmental contaminants. Research is important for the better understanding of the sanding process and also provides data, which are necessary for it's optimization and efficiency improvement. Newly developed twin-disc machine was used to carry out the presented experimental research. The influence of common contaminants on the adhesion is investigated, considering various operating parameters. Different amount of the applied sand is used to increase adhesion in the contaminated contact at various slip and rolling speed. Results show, that there is the amount of the sand, from which no significant adhesion increase occur. Obtained findings and the results presented in this thesis will be used to optimize sanding system, which will contribute to reduce cost associated with sanding and low adhesion.
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Analysis of contaminants in wheel and rail contact
Straka, Tomáš ; Galas, Radovan (referee) ; Kvarda, Daniel (advisor)
Wheel/rail contact is significantly influenced by so called third body – contaminants. Aim of this bachelor’s thesis is to analyse those contaminants in the contact and to create a brief overview. Short introduction into problem of wheel/rail contact is included, followed by description of main contaminants occurring in the contact. This thesis may be used as introduction into contamination of wheel/rail contact problem.
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Influence of friction modifiers composition on traction in wheel-rail contact
Kvarda, Daniel ; Hartl, Martin (referee) ; Galas, Radovan (advisor)
Friction modifiers are a new effective way to control adhesion in wheel and rail contact. The aim of this diploma thesis is experimental study of the influence of the constituents of water based friction modifier on adhesion. Measurement of the adhesion behavior for different friction modifier compositions is carried out on a ball–on–disc laboratory device creating point contact. The introductory part of the experiments describes the effect of individual components on adhesion. Subsequently, combinations of different friction modifier compositions are tested. In conclusion, selected compositions are used for wear tests. The results obtained show that the performance of friction modifiers is greatly influenced by evaporation of base medium.
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Analysis of the effect of friction modifiers composition on adhesion and noise in rail transport
Suchomel, Ondřej ; Galas, Radovan (referee) ; Klapka, Milan (advisor)
The aim of this bachelor thesis is experimental study of influence of composition of water based friction modifier on adhesion and sound pressure level. Experiments are carried out on twin-disk device. Introductory experiments are conducted to determine the conditions for further experiments. The experiments of the individual components follow, and the various friction modifier compositions are tested. From the results, it is obvious that a significant influence on the reduction of adhesion coefficient and sound pressure level has solid lubricant.
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Materials for friction modification within wheel-rail contact
Pláněk, Miloslav ; Kvarda, Daniel (referee) ; Galas, Radovan (advisor)
Problematic aspects of wheel-rail contact can be reduced by application of substances for friction modification. The essence of this bachelor’s thesis is compile overview of substances for friction modification applied on Top of Rail with focus on that one, which are applied to decrease excessive wear and noise. In this thesis, the reader will be firstly introduced to the fundamentals of wheel-rail contact, essence of friction management and partition of substances for friction modification. Next part of the thesis is focused only on substances providing intermediate level of friction. These substances are TOR friction modifiers, TOR lubricants and TOR solid compositions. Thesis describes their composition, ways of application, expected benefits and map commercial products available on the market. The output of the bachelor’s thesis is overview of these substances and their comparison based on theoretical assumptions, test´s results and practice experience. The thesis will allow reader to have better market orientation between available products, which could be wrong tagged by their own producers.
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Development of a tribometer for the adhesion measurement on a real rail
Vodehnal, Michal ; Polach, Pavel (referee) ; Omasta, Milan (advisor)
The submitted master’s thesis describes the development of a tribometer used to measure the adhesion of a real rail. The thesis contains an overview of the basic terms concerning wheel and rail contact. Following that, there is an overview of devicesthat are able to measure the adhesion on a real track. The author's solution includes a design of the tribometer, the proposed measurement methodology and also a description of the individual components. The result of this thesis is a functional device, verified in laboratory conditions and on a real track.
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Experimental Study of Wheel Flange Lubrication
Frýza, Josef ; Dzimko, Marián (referee) ; Omasta, Milan (advisor)
This diploma thesis deals with the experimental study of the influence of operating conditions on the tribological aspects of the wheel flange and rail gauge contact. The wheel flange contact occurs when the vehicle moves on a curve track and it leads to severe up to catastrophic wear regime. For effective reduction of wear is important to apply a suitable amount of lubricant at appropriate intervals into the contact. The issue in this work comprehensively studies using of three laboratory apparatus and six methods that are theoretically and experimentally compared. Assessed are friction, wear, distribution and film thickness of lubricants for different contact conditions. The resulted amount of lubricant and interval of its application eliminates development of seizure at low consumption of lubricant. The understanding of mechanisms that occur in the wheel-rail contact not only helps to reduce operating costs and improved to energy efficiency of movement of vehicle on a track, but it is the basis for safe, reliable and ecological operation of rail transport.
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Top of rail lubricant development
Skurka, Šimon ; Polach, Pavel (referee) ; Kvarda, Daniel (advisor)
Friction modification within the wheel-rail interface is an important way of achieving ecologically friendly transportation of both persons and goods. This thesis aims to develop a new TOR lubricant, which will be able to maintain suitable frictional conditions while securing minimal adhesion required for traction. All measurements were carried out on tribometer MTM in the ball-on-disc configuration. In the first step, individual components were examined. More complex compositions were measured after that and the three best of them were compared with commercial TOR lubricants. The results show a good ability of developed compositions to maintain required adhesion, reduce wear, and all of them had resistivity against over-lubrication. Lastly, the process of lubricant verification before its application in real traffic was discussed.
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