974 resultados para rocket motors
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Tämä insinöörityö on tehty Inchcape Motors Finland Oy:lle. Se on useassa maassa toimiva autoalan yritys ja toimii Suomessa muun muassa Mazda-autojen maahantuojana. Työssä selvitetään, miten suomalainen lehdistö on ottanut uuden Mazdan B-segmentin mallin Mazda2:n vastaan ja miten auton liittyvä tiedottaminen on onnistunut. Mazda2 on edistyksellinen auto, koska sen paino on laskenut edelliseen malliin verrattuna. Uudessa mallissa on myös kiinnitetty erityistä huomiota erilaisiin ympäristötekijöihin, kuten kulutukseen ja päästöihin. Ensimmäiseksi työssä tutkitaan uudesta mallista julkaistut tiedotteet ja referoidaan ne. Tämän jälkeen tutkitaan ja referoidaan puolen vuoden ajalta lehdistön kirjoittamat artikkelit. Artikkeleita myös tutkitaan siitä näkökulmasta, onko tiedotteissa ja lanseerauksessa kerrottu haluttu viesti mennyt läpi. Työn lopputuloksena saatiin kattava kuvaus siitä, mihin asioihin lehdistö on kiinnittänyt huomiota ja mitä asioita tiedottamisessa voisi jatkossa parantaa. Tiedottamisen merkitys markkinoinnissa on erittäin suuri ja niillä saatu huomio on edullista esimerkiksi mainontaan verrattuna.
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El segle XX ha estat un segle de contrastos durant el qual s¿ha produït la més gran contribució del coneixement científic a la solució de problemes de tota la història de la humanitat. Seguint en aquesta línia, la cultura científico-tècnica serà clau al segle XXI, per la qual cosa la capacitat intel·lectual, la imaginació, la invenció i la innovació esdevindran, cada cop més, els eixos motors de la competitivitat dels països. La riquesa de les nacions es basarà en la riquesa de les nocions. La salut intel·lectual i la prosperitat de la nostra nació, i amb ella, el que és més important, el benestar dels seus habitants, dependran de què sapiguem impregnar tots els sectors socials de la cultura de la innovació. I la innovació s'ha d'assolir des del foment sòlid de la creativitat
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Pumppaaminen kuluttaa teollisuudessa huomattavan osan energiasta, joten siellä on myös merkittäviä säästömahdollisuuksia. Maailmanlaajuisesti pumppaus kuluttaa noin viidenneksen sähkömoottorien energiantarpeesta, ja tietyillä teollisuudentoimialoilla jopa yli 50%. Jätevedenpumppaus perustuu edelleenkin pääosin 50- ja 60- luvuilla kehitettyyn tekniikkaan, merkittäviä energiansäästöjä on mahdollista saavuttaa suhteellisen pienillä investoinneilla. Työn teoriaosassa käsitellään perusteet jätevedenkäsittelystä, ja viemäriputkiston rakenteesta. Pumppuja, sähkömoottoreita ja taajuusmuuttajia käsitellään laajemmin keskittyen niiden toimintaan ja toimintaa ohjaaviin teorioihin. Empiirisessä osassa tutkitaan uuden teknologian energiansäästöpotentiaalia erilaisilla mittauksilla, sekä mittausten pohjalta tehdyillä case-analyyseillä. Näitä analyysejä varten työn aikana kehiteltiin laskin, jolla voidaan arvioida energian kulutusta tunnetulle pumpulle, kun tiedetään haluttu toimintapiste. Työssä käsitelty uusi teknologia on mahdollisesti merkittävin uudistus viemäriveden pumppausteknologiaan taajuusmuuttajien käyttöönoton jälkeen. Teknologialla päästään eroon imukaivoista liki täysin, ja sitä kautta saadaan paremmin hallittua monia ongelmia kuten hajuhaittoja. Teknologian merkittävin hyöty on kuitenkin energiansäästö. Perinteisessä teknologiassa taajuusmuuttajat ovat olleet kannattavia, mikäli geodeettisen nostokorkeuden osuus on mahdollisimman pieni. Tyypillisessä uuden teknologian sovelluskohteissa geodeettinen nostokorkeus tulee yleensä olemaan pieni, joten uuden teknologian käyttöönoton kannattavuus on näissä kohteissa erityisen hyvä.
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Centrándonos en la exploración del paciente que ha sufrido o sufre caídas frecuentes, presentamos unas pruebas específicas para valorar el alcance de las alteraciones que provocan pérdidas de equilibrio. Exposición de varios casos clínicos que presentan afecciones podológicas que alteran la estabilidad, y ofreceremos una alternativa de Tratamiento Ortopodológico demostrando su acción en favor del mantenimiento del equilibrio. Conclusiones referidas al diagnóstico y expectativas de Tratamientos Ortopodológicos en los pacientes ancianos.
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The work aims to analyze the possibilities of utilizing old crane driving AC induction motors in modern pulse-width-modulated variable frequency drives. Bearing currents and voltage stresses are the two main problems associated with modern IGBT inverters, and they may cause premature failure of an old induction motor. The origins of these two problems are studied. An analysis of the mechanism of bearing failure is proposed. Certain types of bearing currents are considered in detail. The most effective and economical means are chosen for bearing currents mitigation. Transient phenomena of cables and mechanism of over voltages occurring at motor terminals are studied in the work. The weakest places of the stator winding insulation system are shown and recommendations are given considering the mitigation of voltage stresses. Only the most appropriate and cost effective preventative methods are chosen for old motor drives. Rewinding of old motors is also considered.
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Diplomityön tavoitteena on tehdä lasertyöasemalle liikkuva kolmen vapausasteen akselisto liikuttamaan laser-laitteiston skanneripäätä. Liikkeen tarkkuus ja tarkka toistettavuus ovat tärkeitä. Moottoreiden liikkeen nopeus sekä kiihdytys- ja jarrutusparametrien täytyy olla määriteltävissä jokaiselle moottorille erikseen. Kolmen vapausasteen akselisto muodostetaan käyttäen kolmea askelmoottoria ja lineaarivaihteistoa. Akselisto liikkuu vaaka-, pysty-, ja syvyyssuunnassa. Työssä kehitetään C-kielinen ohjelma käytettävälle prosessorille ja suunnitellaan ohjainkortti lopullista prototyyppiä varten. Moottoreiden ohjaus ja hallinta toteutetaan AT91S256-prosessorilla, jota ohjataan tietokoneen avulla RS-232 -väylää käyttäen. Vaatimuksena on myös mahdollisuus ohjata askelmoottorin sijasta servomoottoreita samalla ohjelmalla. Tietokoneen käyttöliittymä suunnitellaan erikseen.
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En los tiempos que corren la robótica forma uno de los pilares más importantes en la industria y una gran noticia para los ingenieros es la referente a las ventas de estos, ya que en 2013, unos 179.000 robots industriales se vendieron en todo el mundo, de nuevo un máximo histórico y un 12% más que en 2012 según datos de la IFR (International Federation of Robotics). Junto a esta noticia, la robótica colaborativa entra en juego en el momento que los robots y los seres humanos deben compartir el lugar de trabajo sin que nos veamos excluidos por las maquinas, por lo tanto lo que se intenta es que los robots mejoren la calidad del trabajo al hacerse cargo de los trabajos peligrosos, tediosos y sucios que no son posibles o seguros para los seres humanos. Otro concepto muy importante y directamente relacionado con lo anterior que está muy en boga y se escucha desde hace relativamente poco tiempo es el de la fabrica del futuro o “Factory Of The Future” la cual intenta que los operarios y los robots encuentren la sintonía en el entorno laboral y que los robots se consideren como maquinaria colaborativa y no como sustitutiva, considerándose como uno de los grandes nichos productivos en plena expansión. Dejando a un lado estos conceptos técnicos que nunca debemos olvidar si nuestra carrera profesional va enfocada en este ámbito industrial, el tema central de este proyecto está basado, como no podía ser de otro modo, en la robótica, que junto con la visión artificial, el resultado de esta fusión, ha dado un manipulador robótico al que se le ha dotado de cierta “inteligencia”. Se ha planteado un sencillo pero posible proceso de producción el cual es capaz de almacenar piezas de diferente forma y color de una forma autónoma solamente guiado por la imagen capturada con una webcam integrada en el equipo. El sistema consiste en una estructura soporte delimitada por una zona de trabajo en la cual se superponen unas piezas diseñadas al efecto las cuales deben ser almacenadas en su lugar correspondiente por el manipulador robótico. Dicho manipulador de cinemática paralela está basado en la tecnología de cables, comandado por cuatro motores que le dan tres grados de libertad (±X, ±Y, ±Z) donde el efector se encuentra suspendido sobre la zona de trabajo moviéndose de forma que es capaz de identificar las características de las piezas en situación, color y forma para ser almacenadas de una forma ordenada según unas premisas iníciales.
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This paper is a literature review which describes the construction of state of the art of permanent magnet generators and motors constructing and discusses the current and possible application of these machines in industry. Permanent magnet machines are a well-know class of rotating and linear electric machines used for many years in industrial applications. A particular interest for permanent magnet generators is connected with wind mills, which seem to be becoming increasingly popular nowadays. Geared and direct-driven permanent magnet generators are described. A classification of direct-driven permanent magnet generators is given. Design aspects of permanent magnet generators are presented. Permanent magnet generators for wind turbines designs are highlighted. Dynamics and vibration problems of permanent magnet generators covered in literature are presented. The application of the Finite Element Method for mechanical problems solution in the field of permanent magnet generators is discussed.
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Pumppukäytöt vastaavat noin neljänneksestä Euroopan sähkömoottoreissa kulutettavasta sähkötehosta. Energian kallistumisen vuoksi energian säästämisestä ja energiatehokkuudesta on tullut yhä tärkeämpää. Taajuusmuuttajat ovat tuoneet yksinkertaisen säätötavan, jolla suurimmassa osassa pumppukäyttöjä voidaan saada huomattavia energiasäästöjä. Koko energiansäästöpotentiaalin hyödyntämiseksi täytyy kuitenkin pumppujen toimintaa tarkkailla. Tarkkailu voidaan toteuttaa käyttämällä taajuusmuuttajan sisäisiä mittauksia pumpun toimintapisteen määrittämiseen. Tässä työssä muodostetaan kaksi simulointimallia, joilla voidaan tutkia pumppukäytön toimintapistettä ja energiatehokkuutta. Pumpattavan nesteen ominaisuuksien vaikutusta malleihin tutkitaan ja tapoja korjata virhettä selvitetään. Mallien tuottamia estimaatteja verrataan laboratorio ja pilot-kohteiden mittauksiin. Pilot-kohteiden avulla tutkitaan voidaanko simulointimalleja käyttää teollisuuden energiansäästöpotentiaalia omaavien pumppukäyttöjen havaitsemiseen.
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The reaction between hydroxy-terminated polybutadiene and isophorone diisocyanate constitutes the base of the curing process of the most composite solid propellant used in the propulsion of solid rocket propellant. In this work, differential scanning calorimetry and viscosity measurements were used to evaluate the effect of the ferric acetylacetonate catalyst concentration on the reaction between HTBR and IPDI. These analyses show one exotherm, which shifts to lower temperatures as the catalyst concentration increases. The viscosity analyses show that the increase of temperature causes, at first, a reduction in the mixture viscosity, reaching a minimum range called gelification region (increasing the crosslinking density).
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The main purpose of this thesis is to measure and evaluate how accurately the current energy saving calculation in ABB’s new variable speed drive ACS850 works. The main topic of this thesis is energy-efficiency parameters. At the beginning of this thesis centrifugal pump, squirrel cage motor and variable speed drive, including some equations related to them, are being introduced. Also methods of throttling control and variable speed drive control of centrifugal pumps are being introduced. These subjects are introduced because the energy saving calculation in ACS850 is related to the centrifugal pumps usually driven by squirrel cage motors. The theory also includes short section about specific energy of pumping. Before measurements the current energy saving calculation of ACS850 is being introduced and analyzed. The measurements part includes introduction of measuring equipment, measurement results, summary and analysis of the measurements. At the end of this thesis a proposal for an improvement to the current energy saving calculation is being introduced and few proposals are made for new energy-efficiency parameters, which could be added to variable speed drives. At the end are also thoughts
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Hybrid electric vehicles (HEV) have attracted very much attention during the latest years. Increasing environmental concern and an increase in fuel prices are key factors for the growing interest towards the HEV. In a hybrid electric vehicle the power train consists of both a mechanical power system and an electric power transmission system. The major subsystems in the mechanical power system are the internal combustion engine which powers the vehicle; electric power transmission including an energy storage, power electronic inverter, hybrid control system; the electric motor drive that runs either in the generating mode or in the motoring mode to process the power flow between the energy storage and the electrical machine. This research includes two advanced electric motors for a parallel hybrid: induction machine and permanent magnets synchronous machine. In the thesis an induction motor and a permanent magnet motor are compared as propulsion motors. Electric energy storages are also studied.
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Les segones residencies han estat un dels veritables motors del creixement del nombre d'habitatges a la demarcació de Girona, especialment durant la segona meitat del segle XX. L'explotació i especialització de la zona Costa Brava és i ha estat un dels fenòmens mes importants en el panorama constructor no només de la província sinó a nivell de Catalunya. En aquest estudi s'observa que aquest tipus d'habitatge a la Costa Brava ha sofert canvis en l'última dècada (1992-2002). I de fet, el creixement d’aquesta modalitat d'habitatges s'ha localitzat en nuclis específics
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Synchronous machines with an AC converter are used mainly in large drives, for example in ship propulsion drives as well as in rolling mill drives in steel industry. These motors are used because of their high efficiency, high overload capacity and good performance in the field weakening area. Present day drives for electrically excited synchronous motors are equipped with position sensors. Most drives for electrically excited synchronous motors will be equipped with position sensors also in future. This kind of drives with good dynamics are mainly used in metal industry. Drives without a position sensor can be used e.g. in ship propulsion and in large pump and blower drives. Nowadays, these drives are equipped with a position sensor, too. The tendency is to avoid a position sensor if possible, since a sensor reduces the reliability of the drive and increases costs (latter is not very significant for large drives). A new control technique for a synchronous motor drive is a combination of the Direct Flux Linkage Control (DFLC) based on a voltage model and a supervising method (e.g. current model). This combination is called Direct Torque Control method (DTC). In the case of the position sensorless drive, the DTC can be implemented by using other supervising methods that keep the stator flux linkage origin centered. In this thesis, a method for the observation of the drift of the real stator flux linkage in the DTC drive is introduced. It is also shown how this method can be used as a supervising method that keeps the stator flux linkage origin centered in the case of the DTC. In the position sensorless case, a synchronous motor can be started up with the DTC control, when a method for the determination of the initial rotor position presented in this thesis is used. The load characteristics of such a drive are not very good at low rotational speeds. Furthermore, continuous operation at a zero speed and at a low rotational speed is not possible, which is partly due to the problems related to the flux linkage estimate. For operation in a low speed area, a stator current control method based on the DFLC modulator (DMCQ is presented. With the DMCC, it is possible to start up and operate a synchronous motor at a zero speed and at low rotational speeds in general. The DMCC is necessary in situations where high torque (e.g. nominal torque) is required at the starting moment, or if the motor runs several seconds at a zero speed or at a low speed range (up to 2 Hz). The behaviour of the described methods is shown with test results. The test results are presented for the direct flux linkage and torque controlled test drive system with a 14.5 kVA, four pole salient pole synchronous motor with a damper winding and electric excitation. The static accuracy of the drive is verified by measuring the torque in a static load operation, and the dynamics of the drive is proven in load transient tests. The performance of the drive concept presented in this work is sufficient e.g. for ship propulsion and for large pump drives. Furthermore, the developed methods are almost independent of the machine parameters.
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Synchronous motors are used mainly in large drives, for example in ship propulsion systems and in steel factories' rolling mills because of their high efficiency, high overload capacity and good performance in the field weakening range. This, however, requires an extremely good torque control system. A fast torque response and a torque accuracy are basic requirements for such a drive. For large power, high dynamic performance drives the commonly known principle of field oriented vector control has been used solely hitherto, but nowadays it is not the only way to implement such a drive. A new control method Direct Torque Control (DTC) has also emerged. The performance of such a high quality torque control as DTC in dynamically demanding industrial applications is mainly based on the accurate estimate of the various flux linkages' space vectors. Nowadays industrial motor control systems are real time applications with restricted calculation capacity. At the same time the control system requires a simple, fast calculable and reasonably accurate motor model. In this work a method to handle these problems in a Direct Torque Controlled (DTC) salient pole synchronous motor drive is proposed. A motor model which combines the induction law based "voltage model" and motor inductance parameters based "current model" is presented. The voltage model operates as a main model and is calculated at a very fast sampling rate (for example 40 kHz). The stator flux linkage calculated via integration from the stator voltages is corrected using the stator flux linkage computed from the current model. The current model acts as a supervisor that prevents only the motor stator flux linkage from drifting erroneous during longer time intervals. At very low speeds the role of the current model is emphasised but, nevertheless, the voltage model always stays the main model. At higher speeds the function of the current model correction is to act as a stabiliser of the control system. The current model contains a set of inductance parameters which must be known. The validation of the current model in steady state is not self evident. It depends on the accuracy of the saturated value of the inductances. Parameter measurement of the motor model where the supply inverter is used as a measurement signal generator is presented. This so called identification run can be performed prior to delivery or during drive commissioning. A derivation method for the inductance models used for the representation of the saturation effects is proposed. The performance of the electrically excited synchronous motor supplied with the DTC inverter is proven with experimental results. It is shown that it is possible to obtain a good static accuracy of the DTC's torque controller for an electrically excited synchronous motor. The dynamic response is fast and a new operation point is achieved without oscillation. The operation is stable throughout the speed range. The modelling of the magnetising inductance saturation is essential and cross saturation has to be considered as well. The effect of cross saturation is very significant. A DTC inverter can be used as a measuring equipment and the parameters needed for the motor model can be defined by the inverter itself. The main advantage is that the parameters defined are measured in similar magnetic operation conditions and no disagreement between the parameters will exist. The inductance models generated are adequate to meet the requirements of dynamically demanding drives.