Tier One automotive supplier Mahle has developed an electric motor for EVs that uses no permanent magnets. It is not the first to do so, but it is the first to create a motor that is scalable to fit the needs of many sizes of vehicles, from subcompact cars to medium duty trucks.
Mahle says the ability to tune and change the parameters of the rotor’s magnetism instead of being stuck with what a permanent magnet offers has allowed its engineers to achieve efficiencies above 95 percent right through the range of operating speeds. Only the motors used in Formula E cars offer such efficiency, according to New Atlas.
The Mahle motor is also particularly efficient at high speeds, which could help extend the range of electric cars during highway driving.
“Our magnet-free motor can certainly be described as a breakthrough, because it provides several advantages that have not yet been combined in a product of this type,” says Dr. Martin Berger, Mahle’s vice president of corporate research and advanced engineering. “As a result, we can offer our customers a product with outstanding efficiency at a comparatively low cost.”
More:
Magnet-free motors are not unheard of, but most of them require some sort of rotating contact device to send electricity to the copper coils in the rotor. That raises the possibility of more wear and tear inside the motor than a comparable motor that uses permanent magnets would encounter.
But Mahle’s engineers have borrowed ideas from the world of wireless charging to solve the contact issue. Power is transferred to the rotor wirelessly through induction by a coil carrying alternating current. That induces a current in the receiving electrode inside the rotor, which energizes the copper windings that replace the permanent magnets and creates an electromagnetic field.
Most electric motors use permanent magnets made from rare earth minerals like neodymium, dysprosium, or yttrium. Actually, rare earth minerals are not all that rare. The issue is that China controls 97 percent of the world’s supply.
Even those that are mined elsewhere must be processed in China, which is the only country with the ability to make them commercially usable. Recently, China instituted export controls that raised the price of neodymium by 750 percent and neodymium by 2000 percent.
It’s not that the price of copper hasn’t increased as well as the EV revolution moves forward, but it is nowhere near as expensive as those rare earth minerals, which means the Mahle motor should cost less to manufacture.
You can read the whole article HERE.
Source: Clean Technica
