Volkswagen has unveiled a new generation of drive units for its Modular Electric Building platform (MEB). The rear-axle drive APP550 comprises a newly developed power unit that is supposed to offer more power and improved efficiency simultaneously.
We already talked recently about the APP550: this drive unit has been manufactured by VW Group Components in Kassel since mid-March and will be installed in the coming ID.7.
Since then, the key data have also been published: the drive unit is to deliver up to 210 kW and 550 Nm of torque (hence the designation).
Until now, the engine variant used in most MEB models has a power output of 150 kW and 310 Nm. However, when VW published pictures of the last test drives of the ID.7 before its world premiere on the 17th of April, the efficiency of the new electric drive system was emphasized above all.
Germany’s number one car manufacturing group has revealed a few more details. The familiar design with the pulse inverter integrated into the motor housing, rotor, stator, cooling jacket, gearbox, and gearbox housing remains. However, all components have been further developed.
Another lever to increase efficiency is thermal management. For example, in the cooling system of the drive unit, the engineers have entirely dispensed with an electrically driven oil pump (which would, of course, have consumed electricity itself).
Instead, according to the press release, the system can “cool itself via the gear wheels of the transmission as well as specially shaped components for transferring and distributing the oil”.
In addition, the stator has a water-cooling jacket. The combination of these two systems, as needed, is said to be the basis for a further improvement in efficiency – however, this is not precisely quantified in VW’s communication.
There are also optimizations in classic mechanical engineering: polished and specially shaped helical gears are to reduce losses in the gearbox further, and there is also a friction-optimized bearing in the gearbox housing.
The APP550 achieves the high torque of the electric drive through an improved stator with a highly effective number of windings and a larger wire cross-section. At the same time, thin and optimized laminated plate packages are to increase efficiency.
The rotor is equipped as a counterpart with a stronger and higher-capacity permanent magnet. The drive has been reinforced to cope with the resulting torque.
According to VW, the inverter has also been adapted to “provide the high phase currents” to improve performance and efficiency.
“Because the available space has not changed, we were compelled to develop a new drive that achieves significant improvements in performance and efficiency despite being subject to the same constraints,” says Karsten Bennewitz, Head of Drive and Energy Systems in Technical Development.
“That was a great challenge for the Technical Development and Group Components team. However, the result shows that we were able to reduce the use of raw materials while at the same time achieving a considerable increase in vehicle efficiency,” Bennewitz adds.
As a result, the ID. models (and also the MEB vehicles of the other brands in the group and maybe also other manufacturers using the MEB platform in collaboration with VW) should be able to achieve a higher range with the same battery size.
In its press release, VW only confirms that it will deliver “the first vehicles with the new drive generation in a 210 kW (286 hp) variant” probably from the end of the year.
No specific models are mentioned, but the new ID.7 will likely be among the first, as it is scheduled for the market at the end of the year. A rear-wheel-drive ID.3 GTX may also receive this drive variant later.