Daimler AG is continuing to make significant steps in the development of diesel-electric hybrid systems for its Mercedes-Benz trucks. Set for launch at the IAA Commercial Vehicles Show in Hanover is the latest generation Atego Hybrid. With this combined drive technology, savings of up to 15% in fuel consumption and CO2 emissions compared with conventionally powered trucks can be achieved. There is also a reduction in noise pollution, a significant factor for the urban environment in which hybrid drives operate. Already the impact has been immediate as 50 said vehicles, have been purchased by 40 German fleet operators that are keen to put this cutting edge technology to everyday use. Interestingly, these vehicles received a one-off financial incentive said to be worth €22,500 from the German Federal Ministry of Transport’s "Development Plan for Electrically Powered Mobility".
Production has now moved forward putting Mercedes-Benz ahead of the competition in that hybrid traction is available off the assembly line just like its diesel combustion engined counterparts.
Daimler presented its first European produced hybrid at its "Shaping Future Transportation" event in Stuttgart in November 2007. The following year 5 examples of these Mercedes-Benz Atego Hybrids, (in prototype form) went on trial with DHL Express. Despite the economic crisis interest in the full production type has come from France, Switzerland and Austria.
Various technical aspects have since been improved to perfect the balance between the vehicle and the hybrid components. Under the direction of Karl Deppen, Project Leader, New Atego/Atego Blue Tec Hybrid, the second generation Atego Hybrid has gained the same refreshed look as per the diesel model as well as the internal embellishments.
Back in September last year, ITOY jury members drove one of the examples from the DHL fleet around Stuttgart . In his presentation Karl Deppen outlined the significant modifications to the Atego Hybrids since then. For a start, more powerful and lighter high voltage Lithium-Ion batteries are now fitted and the electric engine is fully integrated without the use of an adaptor. Mercedes-Benz Telligent automated transmission now features Hybrid (Eco)-Roll function. In addition the engine‘s Stop/Start function is now fully automatic. Before now it was manually operated. While the 12 tonne 4x2 box bodied rigid with diesel/electric dual-power met with Euro 5 engine emission standards, the latest one goes beyond that and achieve EEV levels – Enhanced Environmentally-friendly Vehicle compliant.
Having gained European Type Approval, right-hand drive and left-hand drive versions are available for the first time. Safety has been enhanced with automatic shutdown in hazardous situations. As before parallel hybrid architecture is used. In other words, the electric motor is located behind the internal combustion engine and clutch, but in front of the transmission. This arrangement enables the engine and electric motor to power the truck individually or together. Compared with a conventional drive, additional components include the batteries powering the electric motor, a converter or voltage transformer and the hybrid control system and cooling system. As the vehicle moves off under electric power, recuperation or regeneration of the energy is achieved through the foot brake, use of the new 2 storage Exhaust Brake and also through the New Hydro-Roll system. As before this 12 tonne GVW hybrid-drive distribution truck is based on the platform of the Atego 1222L Euro 5 4.8 litre four-cylinder EEV engine that develops 218 hp and has maximum torque output of 810 Nm @ 1200/1600 rpm. This is supplemented with a water-cooled electric motor developing a peak output of 44 kW and maximum magnet motor located between the clutch and the 6-speed automated transmission.
"As a self-sustaining system, the Atego Blue Tec Hybrid is not tied to any specific infrastructure for exampled cables or charging stations, its application options are just as flexible as those for pure diesel vehicles," stated Karl. He added, "Depending on the specific system, the additional weight of the Atego Blue Tec Hybrid compared to the regular Atego 1222 comes to around 350 kg."
JARLATH SWEENEY