REPORT FROM BAUMA
Weyhausen Deutz AG, based in Cologne, Germany, presented a hybrid power unit for a wheel loader at the Bauma Trade Fair in Munich last month.

The hybrid project is being developed with Heinzmann and Weyhausen. The companies said the hybrid systems can reduce fuel consumption up to 30 percent.

The companies demonstrated a so-called “mild” hybrid system at the Bauma show, with a motor-generator being installed in the power train between the diesel engine and the hydraulic pump. The companies said such systems allow fuel savings between 10 and 20 percent.

Heinzmann, a manufacturer of engine-control systems and a long-time Deutz partner and supplier, will develop and manufacture the electric unit and power electronics. Because of the company’s modular construction concept, the components can be installed in other types of equipment as well.

During the first development stage of the hybrid power unit, the following system functions will be realized:
· Automatic engine stop during idling phases, automatic engine start in the case of continued operation. The usual starter is omitted.
· Power boost: in the case of power peaks, the electric unit is cut in.
· Battery charging: if the diesel engine has excess power, the electric unit can charge the battery while operating as generator.
· Recuperation: part of the braking energy is re-fed into the battery by the electric unit.

The system will be installed and tested in a Weyhausen wheel loader, with all functions on the equipment side hydraulically driven. In the next step, the wheel loader will be powered by a full hybrid drive system, making it possible to realize a strictly electric, emission-free operation.