Les travaux de recherche présentés dans cette thèse concernent les petites machines à aimants permanents, à flux axial et à auto-commutation électronique ayant la topologie d’un rotor intérieur discoïdal avec des aimants Nd-Fe-B montés en surface et de deux stators extérieurs identiques, chacun avec enroulement triphasé distribué dans des encoches. Après l’examen des topologies candidates pour applications d’entraînement direct basse-vitesse, une modélisation électromagnétique analytique de pré-dimensionnement d’un prototype de telles machines est réalisée. Ensuite, une approche numérique originale est développée et couplée à l’optimisation géométrique des aimants rotoriques en vue de réduire les harmoniques d’espace de l’induction magnétique dans l’entrefer et aussi les ondulations du couple électromagnétique. Des nombreux tests expérimentaux sont effectués sur le prototype de machine pour vérifier son dimensionnement ainsi que pour valider la stratégie d’auto-commutation électronique et de contrôle de base / The research work presented in this thesis is concerned with small electronically-commutated axial-flux permanent-magnet (AFPM) machines having the double-sided topology of an inner rotor with surface-mounted Nd-Fe-B magnets, sandwiched between two outer slotted stators with distributed three-phase windings. After reviewing the small double-sided AFPM machine candidate topologies for low-speed direct-drive applications, the thesis hinges on the size equations and the analytical electromagnetic design of the inner-rotor AFPM (AFIPM) machine topology under study. Original methods of modelling and design optimization of a small prototype AFIPM machine are then proposed with the view to reducing the airgap flux density space-harmonics and the torque ripple by rotor-PM shape modification. Extensive experimental tests are carried out on the small three-phase AFIPM machine prototype in order to validate its proper design and to check its electronic commutation and basic control technique

This project explores the feasibility of the solid-state welding method direct-drive friction welding to be used as a joining method for the nitrogen alloyed steel Uddeholm Vanax SuperClean, produced via processes based on powder metallurgy. Vanax SuperClean cannot be welded using fusion welding methods where the base material melts, due to nitrogen escaping the material, resulting in inferior quality welds. The cost of the material motivates the use of Vanax SuperClean for critical parts in applications, combined with a less costly material for the remaining parts, causing alternative joining methods to be examined. Vanax SuperClean is friction welded to itself and to Uddeholm steel types Stavax ESR and UHB 11. Samples are prepared for a number of examinations. Microstructures of the samples are examined using microscopy, microhardness testing is carried out per the Vickers principle, retained austenite is measured using X-ray diffraction and tensile testing of the welded samples is performed. Defect-free welds are produced in all examined samples, showing that the method is suitable for Vanax SuperClean and that no preheating or slow cooling of workpieces are necessary. The possibility of using friction stir welding as a joining method for Vanax SuperClean is discussed. / Detta projekt undersöker möjligheten att använda trycksvetsningsmetoden friktionssvetsning som sammanfogningsmetod för det kvävelegerade pulvermetallurgiskt framställda stålet Uddeholm Vanax SuperClean. Vanax SuperClean kan inte svetsas med smältsvetsmetoder där grundmaterialet smälter, på grund av kvävgasbildning som resulterar i undermåliga svetsfogar. Kostnaden för materialet motiverar användandet av Vanax SuperClean för kritiska delar i applikationer, kombinerat med ett mindre kostsamt material till övriga delar, vilket föranleder undersökning av alternativa sammanfogningsmetoder. Vanax SuperClean friktionssvetsas mot sig själv, såväl som mot Uddeholmsstålen Stavax ESR och UHB 11. Prov tas fram för ett antal undersökningar. Mikrostruktur undersöks med mikroskopi, mikrohårdhetsprovning utförs enligt Vickersprincipen, restaustenitnivåer mäts med röntgendiffraktion och dragprovning utförs. Lyckade svetsfogar fås i alla undersökta prover, vilket visar att svetsmetoden är lämplig för Vanax SuperClean och att varken förvärmning eller långsamt svalnande av arbetsstycken krävs. Möjligheten att använda friktionsomrörningssvetsning som sammanfogningsmetod för Vanax SuperClean diskuteras.

The thesis deals with the problem of large-capacity manipulation of large forgings with forging manipulator. It describes current techniques, their characteristics, advantages and disadvantages. Based on the analysis of these techniques, the thesis introduces design of the connection of the hydraulic circuit for the drive of the traveling traction wheels of the forging manipulator QKK 100 by ŽĎAS a.s. focusing on simplicity, trouble-free operation, efficiency, economy, change of speed and torque, and possibility of modification according to the current load.

The induction machine with a squirrel cage is a workhorse of the industry. The main advantage of an induction machine is the low manufacturing price, simple and robust construction, low maintenance requirements. However, for high-speed applications, induction machine with a squirrel cage requires design modification due to the mechanical restrictions. The objective of this thesis is to show design process, methodology and assembly of the induction machine for high-speed applications. In this thesis, the rotor dimensioning data are presented. The results are demonstrated on the design of the 6 kW, 120 000 rpm solid rotor squirrel cage induction machine. This thesis also contains calculation and design of three different electrical machine topologies for a turbo circulator application. The electrical machines are designed with 6 kW output power at 120 000 rpm. The machines are estimated by using electromagnetic, thermal, and mechanical calculations. The drawbacks and advantages of each topology under study are described. For other high-speed applications, a comparative method helps in choosing the suitable electrical machine topology by examinations of discussed criteria. Rotor design effect on the electromagnetic performance of the induction machine is shown. Mechanical stresses are calculated with Finite Element Method analysis. Various assembly technologies to produce solid rotor with squirrel cage are discuss and compare. Describe approach enables high electromagnetic performance and durable construction of the high-speed induction machine. Work is confirmed by measurement on the manufactured prototype.

V tomto projektu jsou popsány základy problematiky větrných elektráren. V první řadě práce zmiňuje ekomonické aspekty, vývoj větrné energetiky v minulosti a pravděpodobný vývoj v příští generaci, stavbu a možné topologie větrných elektráren. Dále je ukázána konstrukce větrné elektrárny, integrace větrvých parků do distribuční sítě a ostrovní sítě a související ekonomické aspekty. Dále jsou zmíněny způsoby řízení, kvality elektrické energie a bezpečnosti. V následující části, je provedena simulace moderní přímo poháněné turbíny o výkonu 660kW a řešení koeficientu výkonu. Pro tuto simulaci byl použitý systém s pomaloběžným synchronním generátorem s permanentnímy magnety. Chování a výsledky simulace větrné elektrárny jsou popsány v závěrečné části této práce.

The main task of this master’s thesis is to design circuits for feedback control of the main drives Minidarpa robot. It contains the description of power-driven mobile robot control theory and the DC motor. The second part deals with the design options of the control module and its mechanical design. The last part of the proposal made cascade speed control with current loop by using optimal module and the symmetric optimum methods.

The main content of of this thesis is a construction design and analysis of a machine for cutting tires. The resulting solution emerges from the design options and the option that meets the best selection criteria is chosen. Then the thesis stops for a while at the choice of cutting technology and tries to exemine its suitability for cutting tires. In its other part there is an attempt to clarify the relevant parts of the machine, where the benefits of three-dimensional views is used. Basic design and check calculations are done in the selected machine parts.

This thesis describes the design work for the measurement of air values. The first part describes the airflow, pressure build-up in pipes and losses due to airflow losses. There is also a description of fans and explain their characteristics depending on the pressure generated by airflow. The next part describes the design of the measuring chamber, electronics and control for fully automatic measurement of air quantities.

The main aim of this master's thesis is innovative approach to design of self propelled sprayer with technical, esthetic, ergonomic and economic demands. The final design with it's modern and functional look should be an attractive element of agrotechnics. Another aim is also to fulfill social and psychological functions and address the public about protection of cultivated crops with emphasis on alternative energy and other uses of agricultural machinery.

The master thesis treats the design of control system of special purpose machine tool. The first part analyzes and compares two possible variants of control system which use either a CNC control system Sinumerik or motion control system Simotion. Only the variant with the Simotion control system is subsequently examined in detail: its hardware configuration, the selection of components and partly also the software solution. The thesis further deals with the safety of the realized control system and of the whole machine. There are described general safety requirements of machinery based on harmonized European standards and their specific application in the design of safety functions and the safety circuits of solved machine tool.