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Comparison of mechanical properties of bolts with various surface treatment and upon consideration of their operation on the safety limit
Krško, Peter ; Skalka, Petr (referee) ; Ševeček, Oldřich (advisor)
This bachelor thesis deals with issues of critical bolt joints tightening on the safety limit. The aim of this work is to find the optimal surface treatment of the bolt for reliable application in industrial vacuum pumps and to clarify its stress-strain behaviour upon using various surface treatments and different surface lubrication. Next part consists of finding the maximum torque values causing a fracture in bolts of the vacuum pumps. For this purpose, on one hand, the analytical model of the bolt joint is used and, on the other hand, the experimental observations on the real bolt joint are utilized. The outputs of both approaches are then compared to each other and, on their basis, the most suitable surface treatment of the bolt joint for the given industrial pump is recommended in order to achieve the maximum possible safety against torque applied to the bolt when assembling the device.
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Repair of the turbine housing
Jelínek, Tomáš ; Novotný, Zdeněk (referee) ; Fiedler, Jan (advisor)
This diploma thesis deals with the repair of a steam backpressure single-stage turbine. This thesis is assigned to a specific Spilling turbine case. A revisional report of this turbine with repair or exchange suggestions of demaged turbine parts is processed. In addition, a simulation of the contact pressure is carried out on the split plane of the housing. Structural modifications are designed and simulated to increase the parting plane's tightness. Further, the calculation of the tightening torque of the split plane is performed and a control thermodynamic and strength calculation of the labyrinth seals is performed.
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Retrofit Backpressure Steam Turbine
Hlavinka, Miloslav ; Novotný, Zdeněk (referee) ; Fiedler, Jan (advisor)
Tématem diplomové práce je revize parní turbíny Mitsubishi a výpočet utahovacích momentů šroubů dělící roviny. Tato práce je rozdělena do několika částí. Úvodní část práce obsahuje seznámení s rozsahem prováděných servisních prací na parních turbínách. Poté je zde samotná revize parní turbíny Mitsubishi. Tato revize je dělena podle jednotlivých komponent turbíny. Poté je zde stanoven seznam nutných oprav a také seznam doporučených oprav pro příští odstávku. V další části je zde shrnut výpočet utěsnění dělicích rovin a to s nebo bez odlehčení. Dále jsou rozebrány nejčastěji používané typy závitů spojovacího materiálu parních turbín. Hlavní částí práce je samotný výpočet utahovacího momentu. Výstupem této práce je poté program pro výpočet utahovacího momentu v programu Excel.
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Realization of educational problem based on preloaded bolted joint apparatus
Žaba, Tomáš ; Náhlík, Luboš (referee) ; Vaverka, Michal (advisor)
In the master’s thesis an educational task concerning an experimental apparatus for quantity measurement in preloaded bolted joint is realised. In terms of its preparation an innovation of the apparatus leading to an easier and faster pretension realisation was implemented. The educational task for students and also teaching material were produced. The educational task itself consists in experimental confirmation of the relation between the tightening torque and the caused pretension. An FEM model simulating an apparatus flange deformation by given pretension was designed to verify the experiment. The thesis also contains information about the preloaded bolts, pretension elicitation methods and pretension control methods.
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Draft bolting torque in plastic components
Piňos, Matěj ; Svoboda, Petr (referee) ; Dvořáček, Jiří (advisor)
This bachelor thesis is dealing with problem of screw connections in plastic components. There are universally described screw connections, threads of tapping screws, issue of prestressed bolt connections and ways to make pretension. Knowledge was applied to specific bolt connection (which is in production) to verify the assembly method. The examined connection was put to the destructive test and the test which explores pressure marks on the plastic components. Results were numerically processed and statistically evaluated. The accuracy of current tightening tools was verified too.
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