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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Konstrukce soustružnického sklíčidla se strojově nastavitelnou excentricitou / Design of lathe chuck with machine-adjustable excentricity

Petrych, Jan January 2019 (has links)
This master´s thesis focuses on constructional design of chuck with settable eccentricity in two axes. The first part consists of brief analysis of the clamping of CNC machines and summary of available chucks with settable eccentricity. Next part deals with study of possible construction designs. Two construction variants will be based on those designs in the next part. Following part then describes dimensionality of the main parts of the chuck. Based on the calculations, the 3D model of chosen variant is created with the description of its functionality. Finally the conditions of operation for the chuck are described.
2

Dvouválcový řadový vznětový motor s excentrickým klikovým mechanismem pro užitková vozidla / Two-cylinder inline diesel engine with an eccentric crank for commercial vehicles

Černohous, Tomáš January 2015 (has links)
The goal of this master’s thesis is to examine the influence of eccentricity on the behaviour of forces between the piston and cylinder liner and on balancing of the crank mechanism for given parameters of the diesel engine. Another aim of this paper is to propose an appropriate balancing of the crank mechanism followed by stress analysis considering torsional vibration for a chosen value of eccentricity.
3

Diagnostika vibrací elektrických strojů / Vibration diagnostics of electrical machines

Lexa, Jakub January 2016 (has links)
This thesis deals with vibration diagnostics of electrical machines. The thesis describes vibrations and their measurement. The next section concernes the diffrent modes of elctrical machines. Vibration of machines are divided into electrical causes and mechanical causes. Practical part deals with the measurement of vibration on the machines and their subsequent analysis. The result of the practical part is determining the fault of the measured induction motors.
4

Metody analýzy vibračních signálů / Methods of analysis of vibration signals

Sivera, David January 2017 (has links)
The aim of the thesis is to focus on the different methods of analysis of vibration signals. Focusing on the physical fundamentals of vibrations and a description of their origin in an electrical machine. Describe the vibration sources from mechanical across the electromagnetic to the aerodynamic. Defining the current defects of electric machines and sensors suitable for the measurement of vibrations in an electric machines. Introduction to the methods of analysis of vibration signals in the time and frequency domain. Then using some of these methods for the analysis of vibration signals measured asynchronous motors with different manufacturer defined production defect. The conclusion is composed from the comparison between measured and analyzed results.
5

Hydrodynamická ložiska vznětového traktorového motoru / Plain Bearings for CI Tractor Engine

Petr, David January 2010 (has links)
This thesis deals with the hydrodynamic plain bearings tractor diesel engine. The first part is closer acquainted with the hydrodynamic bearing, its principles and materials used. The next part work deals with the multibody system adams-engine. The main part of this work is to model the crank mechanism and its storage in hydrodynamic bearings in the MBS program and the subsequent simulation under different operating conditions.
6

Pětiválcový řadový vznětový motor s excentrickým klikovým mechanismem / The five-cylinder inline diesel engine with eccentric crank mechanism

Süttő, Daniel January 2014 (has links)
The aim of this thesis is to find out the influence of eccentricity of crank mechanism on the duration of the force between the piston and the cylinder liner. At the same time I wanted to find out its influence on the balance of the whole system. It is important to design the balance for the selected value of the eccentricity and subsequently put through the crank shaft to stress analysis with torsional vibrations. I got so interested in this problem that in addition to the whole topic I designed a torsional vibration damper.
7

Tříválcový řadový vznětový motor s excentrickým klikovým mechanismem pro užitková vozidla / Three-cylinder inline diesel engine with an eccentric crank for commercial vehicles

Domský, Viktor January 2015 (has links)
The goal is to investigate the influence of eccentricity on the force between the piston and the cylinder liner and the influence on balancing of the crank mechanism. For a selected eccentricity suggest a balancing method and perform stress analysis of crankshaft considering torsional vibration. Eccentricity is chosen by the ratio of centric and eccentric mechanism of friction work. The paper shows the effect of eccentricity on the selected kinematics values. Stress analysis is done in the software ANSYS. Using selected eccentricity the friction work was reduced by 10 %.
8

Diagnostika poruch elektrických strojů pomocí vibrací / Fault Diagnosis of electrical machines using vibrations

Čech, Roman January 2016 (has links)
The task of this thesis is to introduce the problems of vibrafon sources in asynchronous motor and their effects and risks to the engine. We will classify the sources of vibration, we will focus for the defects of bearings and for dynamic and static eccentricity. The thesis includes vibration measurement for asynchronous motor, analysis and evaluation of bearings defects and eccentricities.
9

Zazen pro diagnostiku asynchronnch motor / Device for diagnostic of induction machine

Buln, Tom January 2014 (has links)
The aim of the thesis is to study the problems of induction motors, which belong among the most widespread and used machines. Due to their expansion, it is advisable to start the fault monitoring to prevent any more damage and losses. It can be used for condition monitoring different types of methods, which are variety technically and costly demanding to implement. It is used the method of measurement using stator currents in this thesis, because these currents are already monitored and it is easy to create devices for a more detailed analysis. The whole monitoring is carried out using products from National Instruments. The program of monitoring is created in graphical setting of LabVIEW. The analysis is conducted by calculating the Fast Fourier transform of the time signal. The result is the frequency spectrum, which contains frequency peaks and some of these peaks represent failure. The test data are collected with a DAQ device and then the same data are used for creating a methodology for evaluating online analysis and it is subsequently implemented into CompactRIO.
10

Vliv excentricity na radiální síly v asynchronním motoru / The influence of eccentricity upon the radial forces in an induction motor

Formánek, Jakub January 2015 (has links)
The aim of this master thesis is to get familiar with the influence of radial forces in the induction machine. Induction motor is one of the most commonly used and most extended type of machine, therefore it is useful to detect the intensity of theese forces and their influence at operation of the machine. In this work ,radial forces are computed by the software simulation in ANSYS Maxwell. Models are created with help of module Rmxprt and finite elements method.These models are based on real induction motors with predefined size of eccentricity. In the final part we perform a measurement of deviations on the real machine using vibrometer.

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