J. B. Dunlop

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An optimised switched reluctance motor/generator for a mild hybrid electric vehicle is reported. The machine is designed to fit over a torque converter with no addition to the drive train length, while eliminating the starter motor, alternator and flywheel. Measured static torque shows excellent agreement with the torque calculated by finite element(More)
Introduction Magnetic couplings are often preferred in automation engineering and in chemical processing technology as they provide torque transmission without any mechanical contact or losses. Accurate analysis and optimal design are essential to minimise the volume of magnet material and to avoid the construction and testing of multiple models to achieve(More)
The advent of modern rare-earth permanent magnets, which have a magnetic energy product up to an order of magnitude greater than those of Alnico and ferrite magnets, with high remanence and coercive force, has resulted in improved performance of many devices and products. Modern rare-earth magnets, especially neodymium-iron-boron, when combined with(More)
The design of a high torque brushless DC motor to replace the induction motor and worm gear for valve actuators is described. Minimum motor cost, short axial length and low electronics rating are achieved by selection of open slots and coils wound on bobbins. First and second harmonic designs are compared, with either 2 or 4 magnet poles facing 3 teeth. As(More)
The introduction of rare-earth permanent magnets based on samarium-cobalt in about 1970, and neodymium-iron-boron magnets in the mid-nineteen eighties, has ushered in a new era in hard magnetic materials. This has resulted in a dramatic improvement in permanent magnet performance, with neodymium-iron-boron (Nd2Fe14B) magnets having a magnetic energy product(More)
The structure and magnetic properties of magnetite nanoparticles that have been aged in aqueous solutions of different pH for various time periods have been investigated. Aqueous aging results in particle transformations, where the products have different structural and magnetic properties to those of the starting material. It was found that aging in acidic(More)
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