A range of motors could be made more efficiently

Swedish researchers have designed a motor, which they claim would be twice as efficient – and half the cost – of existing devices.
The innovation centres on a new type of magnetic material, coupled with production methods that slash the number of components and reduce the cost of assembly.
The implications are far-reaching and could mean that any device that relies on motors – from a washing machine to a car – could be produced far more cheaply.
The researchers, at Lund University’s Centre for Electro-Magnetic Conversion (Cemec), have spent 15 years creating ‘plastic bonded iron powder’ – in which metal particles are ‘suspended’ in a Plastic Flange material. This compound is used to produce motor components using a technique called ‘centrifugal moulding’.
“The development started with injection moulding of low performance motors,” says Tord Cedell. “We found that new, alloyed powders with very well defined shape and grain structure would give high packing ratio and low losses. Experimenting with other techniques, we understood that a special form of rotational moulding [centrifugal moulding] gives superior properties and high production throughput.”
The energy efficiency of conventional electrical actuators – including motors, inductors and transformers – can be boosted by incorporating a laminated core of soft magnetic iron sheets, he says. Cemec proposes to replace the laminated sheets with a single moulding of ‘soft magnetic composite’. As well as being more efficient, it would be made in just “a few” production steps rather than the 60 that it currently takes, says Cemec.
The likely list of benefits from using this approach includes: reduced size and weight (as the actuator and driven object are integrated, minimising the need for gearboxes or flange couplings); reduced energy consumption (with fewer mechanical parts); and reduced cost (with modular design allowing for cost-effective automated production – so suitable for high labour cost economies).
The Cemec team is already producing inductors, transformers and induction heating coils using the technique – but full-blown motors will take a little longer.
“For mass production of motors and generators, it will be – depending on financing – at least one more year,” he says, noting that Cemec is currently seeking venture capital for this development.