Some of the world’s most powerful magnets, not including electromagnets, are made from the rare-earth metals neodymium, samarium, or yttrium. As a result, rare-earth magnets are expensive, while magnets made of iron, ferrite magnets, are cheaper, but not nearly as strong.
Electric motors only function because of magnetism, and can be made up of arrangements of electromagnets and permanent magnets. By replacing ferrite magnets with neodymium magnets, an electric motor bound for an electric vehicle [EV] can be made smaller and lighter, weight being an important consideration in such an application.
In order to reduce dependency on rare-earth magnets, and therefore costs, Yaskawa Electric set out to produce an EV motor with a ferrite magnet core. The problem with the ferrite magnet, though, was strength, so Yaskawa had some work ahead of it to maximize the power output of the weaker core. First, the shape of the magnet had to be optimized to improve torque output.
Then, Yawaska made a change to the coil wiring itself. Instead of using the standard round-cross-section wiring, Yawaska switched to a rectangular-cross-sectioned wire, which stacks better on the rotor and stator. This resulted in a 30% increase in the number of windings they could put in the same space, increasing the power output over the standard round wire motor.
The resulting EV motor, about the same size as currently found in EVs and hybrids, weighs about 132 pounds and maxes out at 12,000 RPM. With a maximum power output of 80kW and 147 hp at zero rpm, the new motor fits in the range of what’s required for a small EV or hybrid vehicle.
By eliminating rare-earth magnets and combining new processing and optimization, the result is a cheaper motor, which would help to reduce costs of EVs and hybrids alike. Reducing costs would certainly help marketing these high-technology vehicles and help them gain acceptance in such a difficult market.
UPDATE: Phantom Pasting Error Eliminated [First Paragraph]