trailer world issue Two 2010

12 Issue Two 2010 Future II also apportion power with far greater pre- cision than is possible with classic drive systems. In-wheel motors offer exciting possibilities for the design of trendsetting electric truck- train drive concepts. It would be conceivable for example to rethink the classic division of labour between towing truck and towed unit. “Active Wheel” in practice This topic is being investigated by numeroussystemprovidersintheautomotive sector such as Continental, Michelin and ZF. At the IAA, ZF presented a completely new drive unit with the electric portal axle AVE 130 Hybrid. However, this concept and others like it are only intended for use in city buses. The ZF solution is undergoing field tests in MB’s Citaro BlueTec Hybrid bus in various European cities and trans- port authorities. The central feature of this axle system consists of the two water- cooled asynchronous motors each pro- ducing 120 kW (approx. 130 hp). They are suitable both for “occasional jobs” and for recuperating braking energy, as well as for continuous operation in fuel cell or E-buses. At the Paris Motor Show 2008, Michelin presented the “Active Wheel” with an in- wheel motor which is to be used in the “Vol- age” roadster by Venturi, the French electric vehicle specialist, and in the “WILL” compact vehicle by the French electric car manufac- turer Heuliez. Experts have succeeded in ac- commodating both a 30kW electric motor and additional chassis and safety components in the wheel. Where does the power come from? However, practitioners see little chance in the foreseeable future for commercial vehicles used for road freight transport to use revolu- tionary concepts. This has less to do with the actual idea of the in-wheel motor than with currently available drive variations and the ranges they offer. Fuel cell system, electric or hybrid drives may find legitimate use in local public transport buses and in cars, while the existing power supply already solves the prob- lem for electrified railways or tram systems. However, as far as a 40-tonne long-distance truck-train is concerned, these ideas are no more than pipe dreams in view of the current status of technical engineering. This view is confirmed by the Fraunhofer Institute. Dr.-Ing. Michael Jöckel, technical 1900: Ferdinand Porsche as passenger in a “Lohner-Porsche” electric car with four in- wheel engines each producing 2.5 hp. Sporting use: “Volage”, the electric roadster by Venturi with its four in-wheel motors is said to accelerate with a real burst of speed. Photos:PorscheAG,Venturi,Fraunhofer,Graphics:Heins

trailer world issue Two 2010

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