Automotive Supplier MAHLE Developed a Superior Continuous Torque (SCT) Electric Vehicle Motor That Can Run ‘Indefinitely'

author: FutureCar Staff    

MAHLE's superior continuous torque (SCT) high performance electric motor can run “indefinitely” without overheating.

Electric motors with few moving parts are much more reliable than the gas powered engines that power most of the world's vehicles. But advances in electric vehicle powertrain technology may lead to more efficient, smaller and lightweight electric motors, which could help spur the mass adoption of EVs.

Automotive supplier MAHLE, which supplies components to leading automakers Mercedes-Benz, Porsche, BMW, Audi and others, recently announced a breakthrough in electric vehicle motor technology. 

The company developed what it calls a superior continuous torque (SCT) high performance electric motor that the company says can run "indefinitely" without overheating. What's more, the compact and lightweight motor can also be made without any rare earth materials. 

The powerful e-motor paves the way to replace the combustion engine in all types of vehicle classes.

Operating an electric motor in today's EVs continuously at peak output would lead to overheating. But the new MAHLE electric motor uses an innovative integrated oil cooling system that prevents overheating, even during continuous operation at peak output, which is ideal for large vehicles that require significant power under loads. The waste heat generated is used in the vehicle's complete system. The oil flows through the motor using the centrifugal force generated by the rotor. Without the risk of overheating, the motor can essentially "run forever" at close to its peak output, according to Mahle.

The SCT electric motor is designed to be particularly efficient within a certain rpm range, according to Mahle. its continuous output is more than 90% of its peak output. 

This groundbreaking high ratio of power output represents a major technological leap forward and allows its use in electric vehicles of all kinds, including large heavy-duty trucks, buses and construction equipment. The motor's continuous high power output would allow a heavy electric truck to travel up steep mountain passes without overheating, according to Mahle.

"Building large electric motors that deliver short-term high performance is easy. What was still lacking on the market until now were durable yet compact drives to make electric vehicles unrestricted for everyday use," said Martin Berger, Vice President Corporate Research and Advanced Engineering at MAHLE. "Our new SCT E-motor is the solution."

The lightweight and compact have an advantage in the costs of materials and weight since a lighter motor requires less materials to manufacture and increases the possible net load of commercial vehicles.

MAHLE opted for what is known as a permanently excited motor that uses permanent magnets embedded in the rotor to create a constant magnetic field. This allows for a very compact design and no high voltage current needs to be transferred to the windings. This makes the motor efficient and wear-free, according to Mahle. 

The SCT-E motor also uses Neodymium magnets, which are currently the strongest permanent magnets that can be produced. The magnets generate the magnetic field in the motor. 

However, Neodymium is a rare earth material, so the SCT e-motor can also be designed without magnets thanks to a contactless transformer developed by MAHLE. The magnet-free version would also be wear-free and run efficiently, while only requiring slightly more assembly space. 

Mahle's new SCT-E motor will be presented in September at the IAA Transportation conference in Hanover, Germany which showcases the latest trends in commercial vehicles and logistics.

FutureCar Staff