The aesthetic design and thus market appeal of consumer products is limited by the size and weight of the universal or brushed DC motors that they typically employ. As many similar products are displayed for sale side-by-side, it is the aim of any manufacturer to ensure that their product stands out from the rest either in terms of performance, features, aesthetics or ergonomics. This thesis presents the research, design, development and product deployment of two high-speed brushless machines that remove the limitations and restrictions on machine design imposed by mechanical commutation and demonstrates the significant advantages to product design and performance that can be gained by moving away from traditional brushed motor technology. The first machine design is a 3-phase 100,000rpm permanent magnet machine which has been coupled with a high-ratio gearbox to provide a unique drive system for use within a 700W mains-powered electric drill. The research shows that for a given power rating, an optimal motor speed exists for size minimisation of a motor/gearbox transmission system when the design of the corresponding gearbox is also considered. Following the presented optimisation method, a new drive system has been designed that is half the size and 80% lighter than the existing drive, leading to an easy-to use tool that fits within the housing of a much smaller cordless drill product. The second machine is a single-phase, bifilar-wound, 32,000rpm permanent magnet machine for directly driving the impeller of a 200W cordless vacuum cleaner. This lowcost machine demonstrates that a bifilar winding with simple two-switch drive can be successfully applied at this power rating. When compared to the original machine, the presented design shows an axial length reduction from 59mm to 20mm and a 29% reduction in mass. The high speed of the new motor increases the vacuum performance of the product by 70% when using the existing vacuum impeller.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:612619 |
| Date | January 2010 |
| Creators | Leaver, Mark Edward |
| Publisher | University of Newcastle Upon Tyne |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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