UQM patent Reduces Permanent Magnet Use, Cost in EV and Hybrid Motors

Electric drive systems developer and supplier UQM Technologies says it has received a U.S. patent on a new operating geometry for electric motors that require fewer of the expensive permanent magnets that transfer the motor's power into wheel-turning torque.

The system developed by the Colorado company can help reduce the cost of EV and hybrid vehicles' electric motors and the demand for the rare-earth metals used in their permanent magnets.

UQM's engineers developed a component layout that allows a motor to produce the same level of power using 20 to 25 per cent fewer or smaller permanent magnets, said Jon Lutz, the company's vice president for technology.

An electric motor has two basic pieces, a fixed-position stator, or outer assembly which holds the cols of copper wire coils that produce an electro-magnetic field. and the rotor, that contains the permanent magnets.


By reducing the number of magnets needed in an automotive drive motor by 25 percent, Lutz said, UQM can lower the cost of the entire motor by about 5 percent - a savings that can help trim the cost of electric vehicles.

Of course they could use tried and tested AC induction motor technology and reduce their permanent magnet count to zero!