National Repository of Grey Literature 48 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Models and simulations of processes of emission-free wheel loader with electric drive
Cieslar, Filip ; Nevrlý, Josef (referee) ; Němec, Zdeněk (advisor)
This diploma thesis deals with the creation of models simulating the processes of an emission-free wheel loader, which was created by rebuilding the original version with a combustion engine. Part of the work is the methodical creation of models from the basic part of the machine to a simplified model of the overall machine, its functional verification and calibration based on available information’s and measurements. In this paper, selected parameters of the overall machine model are verified based on performed measurements, the suitability of selected components is verified, and the optimization and modification of the model is performed based on verification. The aim of the thesis is to present the simulation and verification procedure and its practical use in the development of an emission-free wheel loader with electric drive.
Control of hydraulic directional valves of mini excavator
Nožka, Michal ; Robenek, Dětřich (referee) ; Nevrlý, Josef (advisor)
This diploma thesis deals with the design of control algorithm for hydraulic directional control valves of a zero-emission mini excavator. Zero emission excavator have same parameters as diesel engine powered version of it. To solve this problem simulations were done for hydraulics and control algorithm of this machine. To find right parameters of simulation models, experiments have been done. There were also proposed some methods to obtain the right set of parameters. The result of this diploma thesis is control algorithm for directional control valves of this very unique mini excavator that doesn't have any competitor (in terms of control algorithm). Set of parameters was also tested during experiments.
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.
Trolley for manipulation
Jílek, Josef ; Nevrlý, Josef (referee) ; Brandejs, Jan (advisor)
This Bachelor thesis deals with solution of interoperative material transport and design of trolley for manipulation of flooring rolls. The trolley was designed with the aim to increase safety and simplify the manipulation. It is simple welded frame made of metallurgical products. The trolley was designed to transport rolls with weight about 150 kg. Factor of safety was 23,5. It means that the construction of frame is well-dimensioned. This thesis also includes complete drawing documentation
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.
Amphibious off-road car with hydraulic drive
Nožka, Michal ; Vlašic, František (referee) ; Nevrlý, Josef (advisor)
The main purpose of this bachelor's thesis is a feasibility study of an amphibious off-road car with hydraulic drive. The first part of this thesis contains basic theory of amphibious vehicles and hydraulic drives of vehicles. The second part consists of chosen amphibious cars and their comparisons. Part of this thesis also suggests hydraulic components that could be used for construction of this car.
Centrifugal radial submersible water pump driven by hydrostatic motor
Holan, Jan ; Vlašic, František (referee) ; Nevrlý, Josef (advisor)
Bachelor thesis is aimed to a design of radial underwater pump with hydrostatic powertrain. Thesis contains base knowledge and working principles of water pumps and parts of hydrostatic powertrain. The other part is aimed to detail description of design and issues related to a water pump design. Thesis was created in cooperation with Center of hydraulic development (CENTRUM HYDRAULICKÉHO VÝZKUMU, spol. s r.o.).
Methods of Reliability Analyses of Operation and Testing Data of Airplanes
Novák, Josef ; Nevrlý, Josef (referee) ; Nejedlý, Ludvík (referee) ; Třetina, Karel (advisor)
The doctoral thesis deals with reliability (dependability) analyses of operation and testing data of the Airplanes. Requirements of airworthiness regulations on aircraft hydraulic systems (with a focus on US FAR-23 and European CS-23 regulations) are taken into account. Mentioned regulations include requirements for the structural design, design of systems, etc. They cover wide range of airplanes from small sport airplanes to 19-seats transport aircraft. Also options for predictive reliability analyses (resources) and reliability tests are discussed in the doctoral thesis. Practical application is done on small transport airplane (currently in the development). The failure report is designed. Expected major contribution of the work is selection and practical application of the most suitable procedures for safety assessment on the field of aircraft hydraulic systems, with a focus on the small transport aircraft. Also the comparison to different data source is shown.
Optimisation of Flow Rates in Lubrication Systems with Progressive Distributors by means of Genetic Algorithms
Vepřek, Jiří ; Pavlok, Bohuslav (referee) ; Bauer, František (referee) ; Habán, Vladimír (referee) ; Nevrlý, Josef (advisor)
This doctoral thesis presents the results of the development of two software programs for the design of progressive distributors and progressive lubrication systems. One of these programs implements a genetic algorithm and the other, which is used to design progressive lubrication systems, implements a parallel genetic algorithm of the island model. The program for the design of progressive distributors was implemented in Java using the NetBeans development environment and the other program was created in Matlab. The thesis further focuses on analytical and computational solutions of the flow of compressible greases seen as viscoplastic fluids. Equations for the numerical solution of the non-steady flow of compressible viscoplastic Bingham fluids were derived and solved by the Lax-Wendroff method in Matlab. As several constants had to be set in the equations, experiments were conducted with the ecological grease Plantogel 2S in the laboratory of the Kaplan Department of Hydraulic Machines, mainly to determine the sound velocity in this grease. The sound velocity was calculated based on the experimental results by applying Fourier transformation and the transition matrix method. In addition to this, the rheological measurements of greases were used. As seen from the results, the ecological greases are actually thixotropic viscoplastic fluids with a significant elastic element. Since a Newton fluid was assumed when calculating the sound velocity, the possibilities of using the transition matrix method for viscoplastic fluids were then considered. No analytical solution of the flow of viscoplastic fluids in a frequency spectrum has been published so far. Because it emerged that greases had a significant elastic stress factor, the problem of the non-steady flow of elastic-viscoplastic fluids was solved numerically between two infinite parallel plates by applying the finite difference method (FDM). The computation was done in Matlab. This doctoral thesis makes a contribution to solving problems related to the design of progressive distributors and progressive lubrication systems used to distribute compressible greases. Considering the complex approach to this field and the achieved results, the thesis also represents a significant contribution to design work.
Determination of efficiency of hydraulic drive with recuperation
Kobza, Michal ; Robenek, Dětřich (referee) ; Nevrlý, Josef (advisor)
In the first part of the thesis is determined efficacy criterion for the individual operating modes of the experimental stand with energy recovery and subsequently are evaluated the records of individual measurements. Energy savings are calculated with using energy recovery. The second part describes the process of digitizing relative fuel consumption map of the engine. Results are confronted with a real application engine in the road roller Ammann AP 240 H. In addition, the master thesis describes the creation of hydrostatic converter block in the program MATLAB/Simulink 2012b. Creating block can be used in the development of simulation models.

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