Austria-based battery pack provider Kreisel Electric (earlier post) has developed a production-ready, automated 2-speed transmission for electric mobility applications in combination with an integrated powertrain architecture specially developed in cooperation with Sala Drive GmbH—both designed for high performance and torque ranges.
Kreisel has applied the systems in an electric sports car, which accelerates from 0 to 100 km/h in around 2.5 seconds, with a top speed of 300 km/h (186 mph).
We set ourselves the demanding task of building an ultra-light, electric supercar based on a historic sports car as the ideal application for our transmission. The challenge here is that there is nothing even remotely like a standard component available here, no matter where you look. So we developed the essential components ourselves on the basis of our own requirements profile.—Markus Kreisel, CEO of Kreisel Electric
The automated 2-speed transmission not only had to be able to guarantee unique acceleration values and top speeds, but also act as a reliable link between the high-performance powertrain and a correspondingly powerful and lightweight battery, which was also specially developed for the vehicle.
The Kreisel Electric 2-speed transmission features an electric lube oil pump with integrated oil reservoir that self-enables on demand for maximum efficiency. Drag losses are reduced due to a friction-optimized bearing arrangement.
Electromechanical gear synchronization offers the shortest torque interruptions through optimized torque and speed control of the electric drive during 0.25-second gear shifts. Further, this reduces thermal impact by friction elements and reduces wear effects. An integrated limited slip differential lock ensures uninterrupted torque transmission even in slippery road conditions.
The transmission also features a modular interface that supports a wide range of applications for motor and transmission arrangements.
At the high end, the transmission handle output values of 600 kW and an input torque of up to 900 N·m.
Sensors continuously monitor all relevant components and combine the collected data in real time in a transmission control unit (TCU). The modular powertrain arrangements allow for 1 or 2 motors per axle just as easily as a single motor. For applications that also require high torques, such as small and medium-sized transporters up to 3.5 tons or trucks and buses up to 15 tons, the automated 2-speed transmission can be adapted to match.