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The effect of proteins on friction of artificial articular cartilage
Plachý, Tomáš ; Nečas, David (referee) ; Rebenda, David (advisor)
This bachelor thesis deals with the influence of the composition of synovial fluid on the coefficient of friction of artificial cartilage. The effect of protein concentration and their combination with other components of synovial fluid on the coefficient of friction of CD hydrogels simulating artificial cartilage is observed. All experiments were performed at a constant load of 10 N, speed 10 mm / s, temperature 37 ° C. In experiments investigating the effect of a combination of hyaluronic acid and phospholipids together with proteins, concentrations corresponding to a healthy individual were used. In experiments where the effect of the proteins themselves and their own combinations was investigated, concentrations corresponding to both a healthy individual and patients with advanced osteoarthritis or patients with aseptic release of the prosthesis were used. The work shows that when using the proteins alone, or their combination, there is a decrease in concentration of friction coefficient with increasing concentration. However, if hyaluronic acid alone or phospholipids alone is added to the protein, the coefficient of friction increases. The reduction occurs only after the addition of the combination of acid and phospholipid.
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Evaluation of lubricants for forming
Svobodová, Hana ; Podaný, Kamil (referee) ; Lidmila, Zdeněk (advisor)
The aim of this diploma thesis is experimental testing and evaluation of the suitability of lubricants for drawing stainless chromium - nickel austenitic steel X5CrNi18-10 and comparison of the results obtained from the work [51]. The testing was performed by modeling the friction between the traction edge and the retainer, which corresponds to the real production process at ACO Industries. The introductory part of the thesis describes the process of deep drawing, followed by a description of tribology and the effect of friction. The individual types and properties of lubricants are described in more detail. The main part of the work deals with the testing of lubricants. The results are then described and evaluated.
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Innovation of guide rail production technology
Zlínská, Marie ; Ohnišťová, Petra (referee) ; Píška, Miroslav (advisor)
This bachelor's thesis provides the new plan of technological process of production of the guide rail used on the splitting machine type SVIT 06155. The current process of component production, which was designed more than 40 years ago, is proving inefficient with regard to current production possibilities. The first part of the work describes the process of splitting the leather, further explains the principle of operation of the machine and then defines the required properties of the guide rail in terms of operating conditions. The analysis of the issue reveals two possible solutions. The first is a change of the material of the guide rail and the second is a change of the coating technology and its composition. The introduction of the experimental part presents the solution, together with the newly designed production process and drawing documentation of the guide rail. The correctness of the design is further verified by the production of the component itself and by the evaluation of the surface condition of the Alicona device using the surface and profile method. Finally, an evaluation is made and recommendations for future production of the component are discussed.
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Untersuchung von Strukturen und Beschichtungen für tribologisch optimierte Umformwerkzeugoberflächen für die Aluminiumfeinblechbearbeitung
Kořenek, Jakub ; Hänel, Thomas (referee) ; Blecha, Petr (advisor)
V rámci bakalářské práce je provedena rešerše ke stavu techniky z pohledu tribologie, tváření hliníku, povlakování, strukturování a v závěru rozdělení tribologických zkoušek a metod jejich hodnocení. V praktické části jsou vyhodnoceny už dříve provedené pokusy na oscilačním tribometru. Následně byly provedeny pokusy tažení pásu s ohybem a bez ohybu s různými parametry pro jednotlivé zkoušky. Testovány byly různé laserové struktury (křížové, liniové, bodové) s variací jejich hloubky a pokrytí vzorků. V závěru práce jsou výsledky pokusů zhodnoceny z pohledu opotřebení, koeficientu tření a stability tribologického systému v průběhu pokusu. Z výsledků vychází doporučení pro následující pokusy a možné oblasti aplikace jednotlivých struktur.
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Improving friction of lubricated contacts by modifying thermal conductivity
Šnevajs, Matěj ; Hartl, Martin (referee) ; Šperka, Petr (advisor)
This thesis deals with an experimental study regarding the effects of the thermal conductivity of contact bodies on the friction, lubricant film thickness and temperature distribution in EHL contact. The thesis focuses on the configuration of the ball on disc contact. The contact body materials are characterized by a wide range of thermal properties. New contact pairs are proposed and used in the study in order to make the contact bodies’ thermal properties dependent on the behaviour of EHL contact. The colorimetric interferometry method is used to measure the lubricant film thickness and the infrared thermography method is used to observe the temperature distribution in EHL contact. The author presents the assumed mechanism of heat transfer within EHL contact on the basis of different heat transfer mechanisms. The same conditions – such as the Hertz pressure, mean entrainment speed, sliding speed and ambient temperature – are induced for all the contact pair combinations. That is why the differences in the results are attributed to the different thermal phenomena in the contact, caused by the thermal properties of the contact bodies. In the case of contact bodies with a reduced heat dissipation capability, a reduction of the friction coefficient of up to 50 % is observed, which is attributed to an increase in the lubricant temperature, resulting in a decrease in its viscosity. This is confirmed by the infrared thermography method, whereby a significantly higher lubricant temperature is observed in the case of a combination of contact materials with a lower heat dissipation capability.
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Multiphase Ti-Ni layer on Ti6Al4V substrate by local nickel alloying
Barančíková, Miriama ; Havlík, Petr (referee) ; Jan, Vít (advisor)
This bachelor's thesis comprises two main parts. The first part consists of a theoretical study on the Ti6Al4V alpha-beta titanium alloy and on the possibilities of adjusting its tribological properties. The second part deals with experimental work with the aim of improving tribological properties of Ti6Al4V by alloying nickel into its surface, creating a hard and homogeneous surface layer with superior tribological properties. In order to achieve these goals, a nickel layer was created on a Ti6Al4V substrate by electrical deposition. The layer was later melted with an electron beam, thus creating a Ti-Ni alloy. Several different parameters of the electron beam were used to create a homogeneous surface layer. This layer was then tested for its mechanical properties. The evaluation of its microstructure was conducted as well. The experiment resulted in the creation of a surface layer with hardness and tribological properties superior to the base material.
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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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Suitable lubricants for deep drawing of steel
Hřebíček, Pavel ; Staněk, Vojtěch (referee) ; Lidmila, Zdeněk (advisor)
The aim of this work is experimental evaluation of suitability of lubricants for drawing of stainless steel 1.4301 at elevated temperature, which corresponds to temperature in real process. The lubricant testing method is based on friction modeling between the pull edge and the retainer, which corresponds to the real process. Therefore, the design of the test fixture also conformed to this model. The result of the work is a comparison of the suitability of every single lubricants with the reference lubricant used in ACO Industries. The best results were obtained with AT Kalorex 650 S lubricant, which contains environmentally harmful additives.
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The introduction of metrological procedures for determining the eligibility of gauges in tribology
Rozlílková, Lada ; Harčarík, Matej (referee) ; Šrámek, Jan (advisor)
This bachelor thesis deals with metrological procedures in determining the capability of measuring instruments in production in a company operating in the field of precision engineering. The main goal of each business is its competitiveness in the industry and the satisfaction of customer. Therefore in companies is a great deal of emphasis on modernizing and optimizing the production process, logistics, and reducing the enviromental impact. The customer's demands are constantly increasing and that is why the accuracy of the product is emphasized. So it is not only necessary to produce the product correctly and accurately, but also to check its quality, whether it fits within the given tolerances and meets the customer's requirements.
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Off-board systems for top-of-rail lubrication
Málek, Jan ; Kvarda, Daniel (referee) ; Galas, Radovan (advisor)
This bachelor’s thesis is focused on rail off-board lubrication system. The main part of this thesis is explaining of function and design few certain lubrication systems. In this thesis are explained aspects of wheel-rail contact, such as types and parts of rail, adhesion, slip, creep–traction diagram. Another part of this thesis is description of few certain lubrication system for top of rail and gauge face application. In this thesis are explained product of major companies of friction management industries such as SKF-Lincoln, Whitmore, Loram. Additional part of this thesis speaks about usage and development of this devices in Czech Republic. Output of this thesis is conclusion about advantages and disadvantages these certain devices.
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