As part of the 25th Aachen Colloquium this week in Germany, Schaeffler is unveiling the “Schaeffler High Performance 48 Volt” concept vehicle. The 48V mild hybrid, based on an Audi TT, features an electric rear axle equipped with a 20 kW motor complementing the internal combustion engine which drives the front axle (P4 architecture). In the demonstrator vehicle, the engine is connected to a 48V belt-driven starter generator.
The Schaeffler electric axle produces a starting torque of up to 2,000 N·m. This provides purely electric driving up to 35 km/h (21.75 mph) as well as active sailing at speeds of more than 70 km/h (43.5 mph).
A further feature of the integral two-speed electric axle is the possibility of torque vectoring, i.e. selectively distributing the drive forces to specific wheels. This improves the agility and safety of the vehicle and the electric axle provides the vehicle with all-wheel drive functionality when combined with the front-wheel drive.
The energy generated during braking is fed back into the energy system via the recuperation function in most of braking operations which reduces consumption significantly. Furthermore, the electric motor and the power electronics are combined into one unit in the Schaeffler electric axle, making important savings in terms of space and mass.
|E-drive configurations. Source: Continental. Click to enlarge.|
Transition to 48V. Automobiles have had a 12Vt on-board electric system for more than 40 years. However, noted Schaeffler, modern automobiles are using less and less fuel while the vehicle’s demand for electricity is increasing due to number of electronic and electromechanical components. Many functions which were previously purely mechanical are now increasingly electromechanical.
Innovative active roll control, electrically controlled turbochargers, advance climate control without using the internal combustion engine as well as stop-start engine systems and mild hybrid architectures are the drivers for a 48V power source.
Schaeffler anticipated high volumes of 48V systems in the future. A 48V motor can be located in any number of different configurations in the vehicle, depending on the design of the system. Schaeffler is providing products for an electrified, 48 Volt future for all hybrid topologies (P0-P4).