The automotive supplier MAHLE has developed a traction motor which is unique on the market and can run indefinitely with high performance. A new cooling concept makes this technological leap possible. The new electric motor is surpassingly clean, light, and efficient and can be assembled without the use of rare earths by customer request. The new development is suitable for passenger cars and commercial vehicles as well as construction machines and tractors. With the SCT E-motor, MAHLE thus becomes a full-range provider in the field of electric drives and covers all needs from e-scooters to heavy-duty commercial vehicles as well as off-road and industrial applications. The new item was presented for the first time at IAA Transportation in September 2022 in Hanover.
“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.”
On the drivetrain side, this clears the way for the replacement of the combustion engine in all vehicle classes. In 2021, MAHLE presented a groundbreaking wear-free and scalable traction motor for passenger cars that runs very efficiently over a wide rpm range.
The SCT E-motor, on the other hand, is designed in such a way that it is particularly efficient within a certain rpm range. Despite its very compact and light design, its continuous output is more than 90 percent of its peak output. Unique on the market, this groundbreaking high ratio means a technological leap and allows the use of electric vehicles of all kinds even under demanding conditions. A classic example is driving an electric truck over mountain passes or the multiple sprints of a battery electric passenger car. These scenarios are only insufficiently covered by the electric motors available on the market up to now.
This resilience is achieved by the new MAHLE electric motor through the use of an innovative integrated oil cooling, which not only makes it more robust but also allows the waste heat generated to be used in the vehicle’s complete system. At the same time, the extremely compact design results in an advantage in the costs of materials and weight—a lighter motor requires less material during manufacture and increases the possible net load in commercial vehicles.
In designing the product, MAHLE opted for what is known as a permanently excited motor, since this type enables a very compact design and no energy has to be transferred to the rotor as “excitation current”. This makes the motor efficient and wear-free. Neodymium magnets, currently the strongest permanent magnets that can be produced, are used to generate the magnetic field in the motor. However, to achieve greater independence from raw material prices and geopolitical developments, the SCT E- motor can also be designed without magnets for greater independence. Thanks to the unique contactless transformer developed by MAHLE, the magnet-free variant would also be wear-free and run efficiently, while only requiring slightly more assembly space.