Mercedes begins series production of e-components
By Mike Brezonick04 October 2021
The Mercedes-Benz powertrain plants in Germany are starting production of key components for the battery-powered eActros. They include the electric axle and the battery packs, which are produced and assembled at the plants in Gaggenau, Kassel and Mannheim. The components will be used for the series production of the eActros, which will begin at the Mercedes-Benz plant in Wörth on Oct. 7.
“The launch of component production for the first series-produced all-electric truck bearing the Mercedes star is of great significance for us,” said Yaris Pürsün, head of Global Powertrain Operations at Daimler Truck. “Because of our battery packs, electric axle and drive system components, we are extensively involved in making the eActros a vehicle of Mercedes-Benz quality that will be locally carbon neutral out on the road.
“Our first series-produced all-electric truck from Mercedes-Benz thus has impressive inner values because key components are produced at our German locations in accordance with top quality standards. This is ushering in a new era for the production and technology network of our German powertrain plants.”
Battery packs from Mannheim
The Competence Centre for Emission-free Mobility (KEM) in Mannheim assembles individual battery modules into complete packs, which it then subjects to a function test. A battery pack for a series-produced eActros consists of six individual battery modules. A completely assembled pack is almost 2.20 m long, 75 cm wide and 55 cm high.
Before the modules become part of an operational pack, they are first installed into a metal housing and then connected to other components such as busbars, control systems and wires. They are then wired to the high-voltage cable sets, after which insulation layers are applied. In the final step, the electric/electronic box (E/E box) is attached to the pre-assembled metal housing, which will later form the interface between the battery and the vehicle. The E/E box is also pre-assembled at the Mercedes-Benz plant in Mannheim. After a final function and leakage test of the entire battery pack, the component is shipped to the Mercedes-Benz plant in Wörth.
Electric axles from Kassel
The Mercedes-Benz plant in Kassel assembles the complete electric axle, consisting of the axle bridge, the electric motor and the shiftable transmission elements. The core axle is pre-assembled, which involves attaching the wheel hubs and the brake disks to the axle bridge. The drive unit, including the two-speed transmission, is pre-assembled in parallel. The Mercedes-Benz plant in Gaggenau supplies the transmission components for this step. After the core axle is pre-assembled, the entire drive unit, including the two-stage transmission, is married to the axle. Before the electric axle is prepared for shipment, it is subjected to a function and high-voltage test which examine electrical safety and noise properties.
The electric axle is mounted on the same basis as its conventional counterpart. As a result, it is possible to integrate the manufacturing and assembly processes of the electric axle into existing production lines in parallel with the conventional production series. This makes the production process extremely flexible and cost efficient, the company said.
Transmission components for e-axles from Gaggenau
The Mercedes-Benz plant in Gaggenau uses advanced manufacturing techniques to produce transmission-related mechanical components and the associated housings. The main challenge is that the transmission parts and the steel and aluminium housing components have to be made as precisely as possible because they are specified to extremely tight tolerances. This is necessary in order to ensure the electric axle works perfectly and has optimal noise properties, the company said.
The range of components produced at the Mercedes-Benz plant in Gaggenau extends from a tiny planetary gear with an outside diameter of 57 mm to a drive wheel with an outside diameter of 365 mm and a raw component weight of over 40 kg. A total of 10 transmission parts and three housing components are supplied to the Mercedes-Benz plant in Kassel, where the further assembly steps of the electric axle take place.