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Sliding contact in electrical machine
Bernard, Ivo ; Skalka, Miroslav (referee) ; Veselka, František (advisor)
The work deals with the sliding contact of electrical machines. The work is focused on individual components of sliding contact and the evaluation qualitative criterions of certain components of sliding contact. In the final section is presented a comparative method that has been designed for large machines. In this work we used this method on a small machine.
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Analysis and Innovation of DC Motors
Štaffa, Jiří ; Mach, Martin (referee) ; Hájek, Vítězslav (advisor)
This work deals with direct-current electric motor, type P2XR49, by firm ATAS elektromotory Nachod a.s. At first there is an introduction with the principal of running, starting, controlling of revolutions and commutating of direct-current machine. The implementation of direct-current machines contains a construction and a list of machine parts, a type of winding and types of small motors that had been used. It is ordered according to a type of excitation. The work includes detailed procedure of admeasurements of speed-torque characteristic mostly used in practice. There is a large number of machine characteristics. The speed-torque characteristic was measured in constant voltage rating into current rating in the direction of rotation CCW upwardly and CW on strength of current rating. Machine innovation, decrease in volt drop on the commutator, was chosen because commutator is the most problematic part of the machine. If the contact pressure is increased the transition resistance will be lesser and consequently the volt drop on the commutator will be lesser.
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DC motors for general purposes.
Randa, Daniel ; Janda, Marcel (referee) ; Hájek, Vítězslav (advisor)
This work deals with innovation DC permanent magnet motor for low power. The work is divided into three tasks. The first part is to survey serially produced DC motors. The second part is to choose one particular DC motor drawn from the survey and carry out its analysis and detailed description. The last part is to design innovations to selected DC motor.
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Automotive Electric Motors Analysis and Innovation
Špaček, Ladislav ; Grmela, Petr (referee) ; Hájek, Vítězslav (advisor)
Direct current motors and stepping motors are very often used for electric drives in cars. The most frequent representatives of direct current motors are electric starter and wind- screen wiper motor. Stepping motors are very often used for electric regulating of outsides driving mirrors and seats. This study is focused on innovation and DC permanent magnet motor. The disadvanage of direct current motors is so called „sliding contact“. A possible compensation of direct current motor are EC (electronically commutator) motors that do not need sliding contact for their work.
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Influence of dust particles on sliding contact
Píšala, Jan ; Janda, Marcel (referee) ; Veselka, František (advisor)
Master's thesis "effect of dust particles on sliding electrical contact" summarizes the sliding contact theory and praxe in rotating electrical machines. The principle of brush machines is described and the working environments are defined. The individual components of the sliding contact and reasons of their degradation are described in detail. Emphasis is placed on the influence of foreign particles, which can be assessed in practice by the method of dust particles. Furthermore, these theoretical knowledge was used in the practical assessment of the technical condition of various machines, as well as the called method. One set of brushes for the traction motor of the locomotive T47.0 was also experimentally innovated.
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Relational Approach to Universal Algebra
Opršal, Jakub ; Barto, Libor (advisor) ; Růžička, Pavel (referee) ; Mayr, Peter (referee)
Title: Relational Approach to Universal Algebra Author: Jakub Opršal Department: Department of Algebra Supervisor: doc. Libor Barto, Ph.D., Department of Algebra Abstract: We give some descriptions of certain algebraic properties using rela- tions and relational structures. In the first part, we focus on Neumann's lattice of interpretability types of varieties. First, we prove a characterization of vari- eties defined by linear identities, and we prove that some conditions cannot be characterized by linear identities. Next, we provide a partial result on Taylor's modularity conjecture, and we discuss several related problems. Namely, we show that the interpretability join of two idempotent varieties that are not congruence modular is not congruence modular either, and the analogue for idempotent va- rieties with a cube term. In the second part, we give a relational description of higher commutator operators, which were introduced by Bulatov, in varieties with a Mal'cev term. Furthermore, we use this result to prove that for every algebra with a Mal'cev term there exists a largest clone containing the Mal'cev operation and having the same congruence lattice and the same higher commu- tator operators as the original algebra, and to describe explicit (though infinite) set of identities describing supernilpotence...
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DC motors for general purposes.
Randa, Daniel ; Mach, Martin (referee) ; Hájek, Vítězslav (advisor)
This work deals with innovation DC permanent magnet motor for low power. The work is divided into three tasks. The first part is to survey serially produced DC motors. The second part is to choose one particular DC motor drawn from the survey and carry out its analysis and detailed description. The last part is to design innovations to selected DC motor.
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DC motors for general purposes.
Randa, Daniel ; Janda, Marcel (referee) ; Hájek, Vítězslav (advisor)
This work deals with innovation DC permanent magnet motor for low power. The work is divided into three tasks. The first part is to survey serially produced DC motors. The second part is to choose one particular DC motor drawn from the survey and carry out its analysis and detailed description. The last part is to design innovations to selected DC motor.
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Analysis and Innovation of DC Motors
Štaffa, Jiří ; Mach, Martin (referee) ; Hájek, Vítězslav (advisor)
This work deals with direct-current electric motor, type P2XR49, by firm ATAS elektromotory Nachod a.s. At first there is an introduction with the principal of running, starting, controlling of revolutions and commutating of direct-current machine. The implementation of direct-current machines contains a construction and a list of machine parts, a type of winding and types of small motors that had been used. It is ordered according to a type of excitation. The work includes detailed procedure of admeasurements of speed-torque characteristic mostly used in practice. There is a large number of machine characteristics. The speed-torque characteristic was measured in constant voltage rating into current rating in the direction of rotation CCW upwardly and CW on strength of current rating. Machine innovation, decrease in volt drop on the commutator, was chosen because commutator is the most problematic part of the machine. If the contact pressure is increased the transition resistance will be lesser and consequently the volt drop on the commutator will be lesser.
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