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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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The effect of real condition of a rail on friction between the wheel and rail
Škubna, Michal ; Hajžman, Michal (referee) ; Omasta, Milan (advisor)
The aim of this master’s thesis is to determine the influence of the friction layer formation conditions on the rail surface on the coefficient of adhesion. Currently, laboratory studies of adhesion are carried out on simplified contact models using tribometers in a two-disc device configuration or in a ball-to-disc configuration, which does not correspond to the real behavior of the wheel-rail interface. The experiments described in this work were carried out in a laboratory environment on a sample of a real rail using a tribometer to achieve variable slip. This made it possible to measure the entire traction curves for the specific rail surface condition. Several experiments were carried out to determine the influence of climatic conditions – especially relative humidity and the effect of water on the development and composition of friction layers naturally formed on the rail. To do this, several procedures were used to achieve the individual friction layers. In addition to the influence of climatic conditions, the influence of simulated passages of rolling stock using a contact simulator was also implemented. The output of the thesis is a draft article describing the methods of preparation of friction layers and the results achieved.
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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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