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822 Uppsatser om Permanent magnet motor - Sida 1 av 55
Aktiv ventilstyrning
To achieve an optimal combustion, an even air/fuel ratio in the combustion chamber is required. An optimal combustion leads to reduced amount of emissions due to a more complete combustion, which is an important matter because of the sharpened environmental laws. This can be attained, among other things, by applying entirely variable cam times. To optimize the engines efficiency and its emissions at all workloads and speeds, an active valve control can be applied. This means that the intake and exhaust-valves can be opened and closed at any time, independent of the crankshaft position.
Prestandautvärdering av permanentmagnetmotor
Examensarbetet var en utvärdering av en synkron trefas permanentmagnetmotor med utvändig rotor. Den är tänkt att ingå i ett batterimatat drivsystem för hjälputrustning på segelbåtar. Målen var att kartlägga prestandan i standardutförande samt att hitta de svaga punkterna i konstruktionen. Förslag på hur motorutförandet kan optimeras ska också läggas fram. Tester och mätningar gjordes i en testuppkoppling med växelriktare, motor och axelkopplad generator. Detta för att kunna få fram fler mätvärden på motorn.
Konceptstudie av drivmodul till bandskotare med hybriddrift
BAE Systems Hägglunds has a long history of producing high performance terrain tracked vehicles (mostly for military applications), and they are now aiming at developing a tracked forwarder with similar techniques.The forwarder will be of series hybrid type where a diesel engine via a generator will power the motors (one for each drive wheel). Thanks to individually controlled motors and the gentle rubber tracks, this forwarder is calculated to have a considerably higher average speed in the terrain and to be more gentle to the soil. The forwarder with a weight of 11 metric tons and a load capacity of 15 metric tons is specified to have an average working speed of 7-10 km/h, a top speed in terrain of 15 km/h and a top speed on roads of 40 km/h.This master?s thesis aims at developing a conceptual design of the forwarder?s drive module which includes electric motor, gear unit, brake and drive wheel.To investigate if the requirements can be fulfilled a study of the dimensioning loading scenarios has been carried out. The resulting needs regarding the torque has been considered in order to determine the required gear ratios for different motor options.
Robotiserad produktionsanpassad magnetmontering för vågkraftverk
This thesis work includes studies and simulation how magnetization of the translator in a linear generator for wave power can be automated. The translator is the moving component in the generator that is "dressed" with permanent magnets. The translator is magnetized with rectangle-shaped permanent magnets that are today's strongest permanent magnet type of neodymium-iron-boron (NdFeB).Eight equivalent metal sheets are mounted around the translator. The plates have milled tracks where 106 permanent magnets per sheet are mounted. Today the assembling of the magnets is done by hand, which is a very tedious and time-consuming work. This project presents investigations about the automation of the translator magnetization theoretically and simulation results are preformed in ABB's robot simulation software RobotStudio. Even robot-held tool was designed that enables the robot to be able to magnetize the translator in a simple manner. The investment cost is roughly 1.5 million SEK. With an economic life-time of five years, the investment costs are estimated to 24000 SEK / month. According to the calculations, this project is very motivated to implement, as it provides savings up to 17 000 SEK per translator which is 10.2 million SEK assuming that the robot cell is operating at full speed the whole year.According to this thesis work the result is a 4x9 meter cell with two industrial robots of the type ABB IRB6650S.The cycle time to magnetize one translator was calculated to about 10 hours.This prototype of project can possibly be implemented in a full-scale production line and performed according to the calculations and simulations presented in the report. Further work is suggested to improve the tool.Lyssna .
Motorikens betydelse för inlärning
AbstractMy purpose with this study is to find out if it helps children who have diffuculties with their concentration if they get to practise their motor behaviour knowledge during their day at the school to promote their learning capacity. My purpose is also to find out how schools works with motor behaviour training. To get answers to my questions have I done interviews with four educationalists and I have also used books and internet sites. Motor behaviour is of importance to how children learn things in the school, without a well working motor children gets difficulties to sit still and to concentrate. The children may put their energy at the wrong things in the classroom, when the energy instead should be need to learning things.
Det permanenta mätfelet: En studie i förändringen av det permanenta mätfelet
This thesis studies the relationship between book values and market values in different assets and liabilities in Swedish Large Cap companies balance sheets. The aim is to find out if the relationship, the permanent measurement bias, has changed during since Mikael Runstens doctoral thesis from 1998 called The Association between Accounting Information and Stock Prices. Although some changes in the permanent measurement bias are found, this probably is due to other aspects than the introduction of IFRS..
Fast driftställe vid internetbaserad verksamhet
It is more common now to purchase products and services on the Internet. More and more companies choose to sell their services and products this way. Some services and products the customers can get delivered directly to their computers. Therefore, it is important for entrepreneurs to know when they risk a permanent establishment in another country due to their Internet based activity. If the company gets a permanent establishment in the other country, the other country can tax the income which is relatable to the company?s permanent establishment.
Motor till unikt luftvärmeväxlarsystem
Gtherm is an innovation company who has an unique air heat exchanger underdevelopment. The purpose of this thesis is to provide data of suitable motors for theheat exchanger and to find suitable motor suppliers.A motor specification was designed. It is an important basis for the search of suitablemotors. A compilation was made of nine motor suppliers and the suitable motorsfrom those. The compilation can be used by GTherm in their choice of suppliers andmotors.The compilation of the demands on the motor and analysis of suppliers indicated thatthere were no standard motors available to GTherms air heat exchanger.
Förskolans balansgång mellan fri- och styrd rörelseträning : en kvalitativ studie om förskolors arbete med rörelseträning
AimThe aim with this essay has been to investigate how preschools profiling in motor activity training, work to stimulate motor development of children. In order to study this, the main focus for the research has been on the following queries:What characterize motor activity training at the preschools studied?What is the purpose with the motor activity training of preschools which were studied?How do the preschools describe the affect that motor activity training has on children?How do the preschools look at the need for motor activity training?MethodFour in-depth interviews were conducted with representatives of the chosen preschools profiling in motor activity. My selection was based on a strategic sample and this was made by an internet mapping of preschool activities in the districts of Stockholm, and information from the service guide of the town of Stockholm. Then e-mail was sent to ten contact persons at preschool units, and ten preschools were contacted directly by phone.
Magnus Magnet : Ett arbetsmaterial för undervisning i fysik i grundskolans tidigare år
Syftet med detta utvecklingsarbete var att utifrån ett nyfikenhetsperspektiv skapa ett arbetsmaterial riktat till förskoleklass och skolår 1 i ämnet magnetism, samt att ta reda på vad begreppet nyfikenhet innebär.Produkten bestod av en högläsningsbok (Magnus Magnet) samt en lärarhandledning med arbetsgång och praktiska övningar. Materialet utvärderades av tre lärare och en lärarstudent. Utvärderingen var mestadels positiv och eleverna tyckte generellt att boken var rolig och underhållande. Till viss del kunde det konstateras att arbetsmaterialet väckte nyfikenhet hos eleverna om fenomenet magnetism. Slutsatsen var att en högläsningsbok samt praktiska övningar om magnetism är en bra metod för att förmedla nyfikenhet och intresse inför naturvetenskapliga fenomen till barn i de första skolåren. .
Batterilös strömförsörjning av strömsnål granatelektronik
Detta examensarbete har utförts vid Saab Dynamics AB(SBD) i Karlskoga med syftet att studera gamla konstruktioner av set-back-generatorer. En set-back-generator (SBG) ska ge momentan energi vid utskjutning av en projektil genom att en magnet rör sig genom en spole. SBG har funnits länge men har bedömts ge för lite energi för att kunna driva elektronik. Men nya typer av magneter har potential att öka energiutbytet väsentligt.SBD har ett antal äldre SBG:er och arbetet har varit att utifrån dessa undersöka om det går att utvinna mer energi genom ett utbyte av magnet. Andra parametrar som är viktiga för en SBG:s funktion har också studerats och testats i olika konfigurationer i hopp om ytterligare förbättringar.
Hur främjar förskollärare barns motorik i förskolan och hur viktig anser de att den är?
AbstractThis work is about children?s motor activity. You can often hear in media about sedentary children, and that one of the factors which contributed to this is computers and things like that. The main goal with this work is to find out how preschool teachers take care of children?s joy of movement and how they work to promote children?s progress of motor activity.
Utvärdering av en Magnetic Harmonic Traction Drive
In this report a new gear concept is evaluated using the magnetic finite element method (FEM)software MagNet and Ansys as well as the mechanical FEM software Abaqus. The gear conceptis evaluated in terms of maximum torque capability, torsional stiffness, gear ratio and efficiency.ABB Corporate Research has proposed a new gear concept which should be less expensive thangearboxes used today. The new concept is called aMagnetic Harmonic Traction Drive and usesthe principles of a harmonic drive gear to achieve a high reduction ratio. The gear conceptreplaces the wave generator used in traditional harmonic drives with magnets and uses tractioninstead of gear teeth to transfer the torque. The main components in the gearbox are the magnets,the flexspline, the magnetic portion and the circular spline.
FPGA baserad PWM-styrning av BLDC-motorer
This thesis work contains a litterature study about electrical motors in general and how PWM-patterns for brushless DC-motors can be made. A suitable method has been implemented as a simulation model in VHDL. A simulation model of a brushless DC-motor which describes the phasecurrents, torque and angular velocity has also been made. The motor model made simulations easier for the complete PWM-system. The design was synthesised and tested with a prototypeboard including a SPARTAN II FPGA.
Vardagliga icke-produktiva motoriska beteenden : förekomst och korrelation med sensation seeking
In everyday life we perform motor behaviours that have no apparent instrumental function. Are these correlated to sensation seeking and do they differ depending on what situations we are in? University students in Örebro (N=108), participated in the study. The participants were asked to fill out a double questionnaire containing the sensation seeking scale and another one for measuring non-productive motor behaviours. The non-productive motor behaviours were not correlated to the sensation seeking scale.