ZF, Continental form hybrid truck drive alliance

BERLIN, Ger. — ZF and Continental AG have finalized a strategic alliance to develop and produce hybrid drives for commercial vehicles.

ZF will provide the parallel hybrid transmission, while Continental will provide the lithium-ion battery accumulator and system electronics. In addition to pure hybrid technology (transmission, electric motor, and power electronics), ZF is responsible for system integration and controls.

"The parallel hybrid concept can be implemented by utilizing existing vehicle driveline resources," explained Rolf Lutz, Group Executive of the Commercial Vehicle and Special Driveline Technology division, ZF.

The cooperation stipulates that Continental — already using Li-ion batteries for passenger car volume production applications — further develops the battery technology with ZF, with volume production scheduled for 2011. The energy-accumulating systems are developed by Continental in Berlin and by ZF in Friedrichshafen, Germany.

This system will be integrated in hybrid drives for light trucks used primarily for deliveries within urban areas. The hybrid system is set up to support the combustion engine during vehicle start-up and at lower speeds (boosting).

In this new commercial system, ZF prefers the concept of a parallel hybrid where the electric motor and the combustion engine can be actuated in parallel via the transmission, and, if needed, separated by a clutch.

The flexible design can be installed in both mild and full hybrids, which use the entire range of hybrid functions: the start-stop function, regeneration of braking energy (recuperation), boosting, and electric starting. In this context, vehicles equipped with full hybrid systems can achieve a 30 percent fuel economy improvement.

In addition the system does not require additional installation space. The hybrid variants based on the parallel hybrid concept transmission, can be integrated into the existing driveline of current ZF manual or automatic transmissions.

In current applications, the Power Take Off (PTO) unit permanently requires fuel because it is mechanically connected to the combustion engine. The powerful generator and the hybrid battery in this new system allow for the use of electric PTOs that consume fuel only while being operated (power-on-demand).