MAHLE is developing the most durable electric motor to date for passenger cars, commercial vehicles, and construction machinery and tractors. A clever cooling concept makes it possible.
SCT stands for Superior Continuous Torque, which translates into plain language as follows: This electric motor can operate at high performance for an unlimited period of time. And that was previously not possible in this form.
The SCT e-motor is designed to be particularly efficient within a certain speed range. The continuous output is 90 percent of its peak power - despite a very compact and lightweight design. This is unique so far.
In the electric motor sector, this is a technological leap that makes its use in electric vehicles of all kinds possible even under challenging conditions-such as passenger cars, commercial vehicles, construction machinery, and tractors. MAHLE is thus becoming a full-range supplier of electric drives. From e-scooters to industrial applications, the company covers all ranges. On the engine side, this paves the way for replacing the combustion engine in all vehicle classes.
The secret behind the motor's can extremely high load over a long period of time is an innovative integrated oil cooling system that dissipates the heat generated. This means that the motor always remains within the optimum temperature range. On the one hand, this makes it robust. On the other, the thermal management system can simultaneously use the waste heat generated to heat the vehicle. The compact design reduces material costs and weight: a lighter engine requires less material in production and at the same time increases the possible payload in commercial vehicles.
Driving an electric vehicle for a very long time at very high performance? Conventional e-motors can deliver very high performance, but not indefinitely. If the peak performance is called up on an e-drive, a lot of heat is generated very quickly, which would damage the motor in the long term.
That's why the power is lowered in continuous operation to keep the system in the optimal temperature frame. As a result, peak and continuous performance differ, sometimes significantly, in an electric vehicle. This heat phenomenon due to overheating makes the use of electric motors impractical in many areas.
A classic example is driving a fully loaded e-truck over a mountain pass. In such a situation, sudden loss of power is unacceptable.
When designing the SCT electric motor, MAHLE opted for a so-called "permanently excited motor". This means that no energy has to be transferred to the rotor as "excitation current," which makes a very compact design possible. As a result, the motor operates efficiently and without wear.
Neodymium magnets are used to generate the magnetic field in the motor. These are currently the strongest permanent magnets that can be manufactured. However, the SCT E-motor can also be designed without rare earths.
Even in the magnet-free version, it operates wear-free and efficiently thanks to the unique contactless transformer developed by MAHLE, while requiring only slightly more installation space.
In 2021, MAHLE had already presented a magnet-free electric motor that does not require rare earths. This not only makes production more environmentally friendly, but also brings advantages in terms of costs and raw material security.
The central feature of the motor is the inductive and thus contactless power transmission - through it, the motor works wear-free and particularly efficiently at high speeds. The efficiency in the most frequently used driving conditions of the drive system is more than 95 percent - a value that has so far only been achieved by Formula E racing sports cars.
MAHLE has thus succeeded in combining the strengths of various e-motor concepts in a single product.