ZF is presenting new electric drives for passenger cars and light commercial vehicles. This latest generation of e-drives advances power density and energy efficiency due to numerous innovations at both the component and system level. These include the compact design of the drives, power electronics, and a resource-saving use of materials, which also makes the production of the drives more sustainable.
ZF’s new electric drive
With their modular concept, the new ZF e-drives support automotive manufacturers in customizing the further electrification of their entire model range. For end customers, the new technologies offer higher efficiency, more power, and shorter charging times.
ZF’s new generation of electric drives is based on a modular overall concept with integrated electric motor, inverter, transmission, and software. With its high level of interface expertise and know-how for driving strategies, ZF application engineers can meet customer requirements fully. However, the Group will also offer the innovative components individually, on which its own system solution is based.
Thanks to sophisticated internal interfaces, the new, extremely compact design allows system or component adaptations to be made with little effort. In addition, the design has very high structural rigidity, which enables superior noise behavior.
—Dr Otmar Scharrer, Head of Development for Electric Drive Technologies
The new generation of ZF e-drives will be available on the market as a complete system starting in 2025; ZF will bring individual components into series production earlier. The following innovations at component level make their contribution to the advanced overall system:
Power electronics manage the balancing act between a high degree of component uniformity and high adaptability. The individualization takes place at the chip level: A discretely structured ZF inverter is built with individual power semiconductor switches. This modularity offers better performance scalability than is possible with complex power modules. In addition, ZF’s “discrete package technology” requires fewer types of components than using conventional power modules.
With a new, highly integrated e-motor, ZF increases the power density compared to the technology currently available in the market. A new cooling concept and a new winding technology play the decisive role here. Due to the new cooling concept, ZF allows oil to flow directly around the copper rods—exactly at the point where most heat is generated during operation. Such highly efficient cooling significantly increases performance with the same weight and installation space. The continuous power of the electric motor is increased to up to 85% of the peak power.
E-Motor Stator with new braided winding
In addition, the use of heavy rare earths can be largely dispensed with, and the e-motor can thus be produced more sustainably. The braided winding technology developed by ZF, a further development of the hairpin winding, enables a total of 10% less installation space. The winding head alone is around 50% smaller than with conventional approaches. This means that around 10% less raw material is processed.
With its new coaxial reduction gearbox, ZF transfers its know-how in planetary gearboxes to the next generation of electric drives. Two integrated planetary gears not only generate the desired axle ratio, but also include the fully integrated differential function. Compared to common offset concepts, the new solution reduces weight and installation space requirements without compromising efficiency, noise, and vibration.
Integrated differential gear
High-voltage converters (DC-DC converters) play a central role in fuel cell-powered electric drives. They compensate for the low output voltage and the strong voltage drop at high load of the fuel cells. The new high-voltage converter from the ZF power electronics platform, which was developed for passenger car and commercial vehicle applications, has a top value of 99.6% in terms of efficiency.
New high voltage converter