With its new electric 2-speed drive solution, ZF wants to herald the next stage of electric mobility in the passenger car segment. “For the everyday use of electric cars, it is important to gain as much range as possible from one battery charge,” says Bert Hellwig, Head of E-Mobility at ZF. According to Hellwig, “Every percent efficiency in efficiency translates into two percent more range.
The solution not only consists of an automatic transmission, but also includes a newly developed electric motor with a maximum output of 140 kW. Both components are matched to each other. Together with the space-optimized design, the drive system is interesting for compact cars, among others. Thanks to its modular design, the unit can also be tuned for performance and thus scaled for use in sporty vehicles.
Vehicles with the new 2-speed drive have lower energy consumption, which in turn leads to an increase in range of up to five percent compared to the usual single-stage units. The gear change takes place automatically at 70 km/h. However, by connecting to the vehicle’s CAN communication, other intelligent shift strategies can also be implemented, depending on the vehicle manufacturer’s wishes – which are linked to digital map material and GPS, for example. The vehicle could, for example, use the route programmed in the navigation system to determine how far away the next charging station is and switch to an eco mode in advance. It would also be possible to change gears more effectively in demanding topographical conditions, on the motorway and during overland journeys. In addition, thanks to connecting to cloud services, the drive’s software could be updated via over-the-air updates.
For vehicle manufacturers, the new 2-speed drive offers two options for making effective use of the improved efficiency. As an alternative to increasing the range with the same battery size, the OEM could opt for a smaller battery. Or a combination of both.
But the 2-speed concept also offers advantages for OEMs who pursue the performance concept. Until now, vehicle manufacturers had to choose between a high initial torque or a higher final speed for electric drives. The developers of the 2-speed drive want to resolve this conflict of goals, because the new drive will be compatible for powerful and heavier vehicles – for example for passenger cars towing a trailer. With a modular approach, ZF will be able to combine the 2-speed transmission with even more powerful electric machines up to 250 kW, which promises better acceleration values and potentially higher top speeds. Thus, the new drive can meet different requirements on the basis of a modular concept.