A new e-motor from Mahle is said to be able to operate at high power for an unlimited time – thanks to an innovative cooling concept. The e-motor is suitable for passenger cars, commercial vehicles, construction machinery and tractors.
Automotive supplier Mahle has developed the high endurance "Superior Continuous Torque" (SCT) e-motor and has now presented it in a digital media briefing. The traction motor is said to be able to operate at high power for an unlimited period of time. This is made possible by a new cooling concept. According to Mahle, the compact e-motor, which is designed to resolve the discrepancy between peak power and continuous power, is suitable for passenger cars, commercial vehicles as well as construction machinery and tractors. The new e-motor is to be shown to the public for the first time at the IAA Transportation in Hanover in September 2022.
As Dr. Harald Straky, Vice President Electronics and Mechatronics, explained during the media briefing, the SCT-E motor will make Mahle a “full-range supplier in the field of electric drives” – covering needs from e-bikes to off-road applications. Dr. Martin Berger, head of Mahle Group Research and Advance Engineering, adds that already today more than 60 % of the Group’s sales are independent of the passenger car combustion engine. By 2030, this share is expected to rise to 75 %.
Permanent delivery of 90 % of peak performance
Last year, Mahle unveiled a wear-free and scalable traction motor for passenger cars that operates very efficiently over a wide speed range. The SCT electric motor, on the other hand, is designed to be particularly efficient within a specific speed range. According to recent test bench results, the motor’s continuous power output is over 90 % of its peak power. This is to enable an e-truck to drive over mountain passes, for example, or repeated sprints by a battery-electric car.
To achieve this load capacity in the new SCT-E engine, an innovative, integrated oil cooling system has been developed. In this process, he said, the routing of the fluid is critical. According to Straky, "you get the heat away from the engine right where it’s generated". The oil cooling is intended not only to make the e-motor robust, but at the same time to enable the waste heat generated to be used in the vehicle’s overall system. The compact design also results in material cost and weight advantages.
Also available without rare earths
When designing the motor, Mahle opted for a permanently excited motor, as this design allows for a very compact construction and no energy has to be transferred to the rotor as "excitation current". This makes the motor efficient and wear-free. Neodymium magnets are used to generate the magnetic field in the motor. At the customer’s request, however, the motor can also be made without magnets – and thus without the use of rare earths. According to Mahle, the company is currently entering into application development with customers interested in the motor.