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Mixed-flow submersible water pump driven by hydrostatic motor
Para, Marcel ; Ranuša, Matúš (referee) ; Nevrlý, Josef (advisor)
Bachelor thesis solves the problem of a submersible, diagonal hydrostatic pump. This study describes the basic principles of hydraulics and equipment. The possibility of engaging the hydrostatic system as an amphibious vehicle is investigated in the Bachelor thesis. The work is written in cooperation with the sponsor of HYDRAULIC RESEARCH CENTRE, spol. S.r.o., which is part of SPL Holding., Inc.
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Experimental study of artificial articular cartilage friction
Kulíšek, Vlastimil ; Ranuša, Matúš (referee) ; Rebenda, David (advisor)
Many conventional materials are used to replace damaged articular cartilage, which are beginning to be replaced by innovative biomimetic materials that mimic cartilage properties. One of these materials are poly(vinyl alcohol) (PVA) hydrogels crosslinked by freeze-thawing and cast-drying method. These hydrogels possess similar mechanical as articular cartilage. In order to clarify the effect of kinematic conditions on the friction of hydrogels, three levels of sliding speed and load and a uniform lubricant – PBS were chosen. The coefficient of friction of the FT hydrogel decreased with increasing load. The dependence of the sliding speed did not show a uniform trend and corresponded to the adsorption-repellent model for PVA gels. The coefficient of friction of the CD hydrogel increased with increasing sliding speed according to the repulsion-adsorption model for PVA gels. The increase in load at low sliding speeds of CD hydrogel caused a slight decrease in the coefficient of friction. At the highest speed, there was an optimal load at which a low coefficient of friction was achieved. The CD hydrogel showed a lower coefficient of friction than cartilage. The FT hydrogel achieved a lower coefficient of friction than cartilage only at 5 N and 10 mm s- 1. This work contributes to the understanding of the tribological properties of PVA hydrogels.
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Equipment to vehicles energy recovery simulation
Ranuša, Matúš ; Jurík, Miroslav (referee) ; Nevrlý, Josef (advisor)
The bachelor thesis deals with design and construction of an experimental device – stand for simulation and recovery energy at utility vehicles. The first parts of the thesis describe principle and process of experiment in the University of Wisconsin Madison and thesis deals with selection of hydraulic components in cooperation with company Bosch Rexroth. The second part of the thesis deals with calculation and construction proposal of the flywheel which meets the requirements of mathematical model and other parts of model. Result of the thesis is complete 3D model of experiment stand suitable for tests energy recovery in applications. Precise determination of the effectiveness of hydrostatic recovery is one of the objectives of experiments that will be implemented at the test stand.
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Analysis and optimalization of pneumatic system of race pneumobile
Navrátil, Lukáš ; Nevrlý, Josef (referee) ; Ranuša, Matúš (advisor)
This thesis deals with the theoretical design of the new pneumatic system, which should lead to increased performance and fuel racing pneumobilu Blowfish. After the theoretical proposal deals with the analysis of both the new pneumatic circuit, and the old pneumatic circuit. The culmination of this work will be participating in the competition with the pneumobil in Hungary, Eger. The first part describes the current state pneumobilu contest and its rules. Further there are described in detail pneumatic elements that are used to pneumobilu. In the second part contains measurements that verify the effectiveness of the new pneumatic circuit.
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Design of a steel pipe dril
Montag, Jakub ; Dočkal, Kryštof (referee) ; Ranuša, Matúš (advisor)
The goal of this work is to create a drill that can drill into steel pipes. Part of the work is designing the drill in a way, that drilling into the pipes is as easy as possible. The output is a drawing documentation that can be used to make a prototype. The designed drill will enable faster, more accurate and safer drilling into steel pipes for mass production.
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Development of the coefficient of friction and lubrication film in a total knee replacement during a gait cycle
Odehnal, Lukáš ; Horák, Zdeněk (referee) ; Ranuša, Matúš (advisor)
This master´s thesis deals with the experimental analysis of the coefficient of friction and lubrication film in total knee replacement. The experiments are performed on a knee joint simulator, with an implemented module for measuring friction. To observe film formation, fluorescent microscopy is used. The experiments are mainly focused on a detailed description of the influence of parameters occurring during the gait cycle. This approach should significantly help in describing the tribological processes that occur in the total knee replacement. The results confirm previous investigations in terms of axial load, where the coefficient of friction decreases with the increasing load. In the case of lubrication film, no significant changes are observed. On the contrary, while investigating the influence of SRR, noticeable changes in film formation are observed while the coefficient of friction being unaffected. While describing the whole gait cycle, precise results are obtained only in the first half of the cycle as the second half is accompanied by the occurrence of large deviations from a rapid decrease of load. This work provides a better understanding of the field of lubrication film in total knee replacements. Moreover, thanks to the simultaneous measurement of the coefficient of friction and the observation of the contact area, it is possible to draw better conclusions than if the experiments had been carried out separately.
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Influence of viscosupplementation on cartilage lubrication
Ondra, Martin ; Horák, Zdeněk (referee) ; Ranuša, Matúš (advisor)
This work deal with the determination of the effect of viscosupplementation on the lubrication of articular cartilage in the beginning phase of osteoarthritis. This effect was evaluated based on the development of CoF measured by a tribometer in configuration pin-on-plate. The tribological model of incipient osteoarthritis was simulated by using two articular cartilages lubricated with osteoarthritic synovial fluid to which viscosupplementation agents were added. These preparations differed mainly in cross-linking and molecular weight of hyaluronic acid (HA). Measurements have shown that viscosupplementation may be effective in the beginning phase of osteoarthritis. The efficacy of viscosupplementation preparations with cross-linking HA was significantly higher compared to the efficacy of viscosupplementation preparations without cross-linking. These results support the use of viscosupplementation to delay the advanced stage of osteoarthritis.
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Design of mounting table for assembly of printing block onto hub according to micropoint
Navrátil, Václav ; Ranuša, Matúš (referee) ; Kučera, Petr (advisor)
The aim of this bachelor’s thesis is to create a draft for the design of mounting table for assembly of printig plate onto sleev according to microdot for newly designed mounting machine made by company Soma Engineering. The first part of the thesis includes the profile of the company, the principle of flexoprint and overview of other companies‘ machines. The second part focused on draft of possible versions of the solution, their pros and cons and estimated costs of individual solution. The third parst of thesis is dedicated to a chosen version and its detailed elaboration.
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