Search Results

Nowadays the task to diminish energy consumption and air pollution caused by road traffic occupies a key issue. One of several approaches is the hybrid driveline technology. At the Technical University Munich through a research project the “Optimized CVT-Hybrid-Powertrain” was designed and manufactured and is under investigation. This research project is run in close cooperation between university and industry (EPCOS AG, GM Powertrain Europe, ZF Friedrichshafen AG and ZF SACHS AG). The project is focused on reduction of fuel consumption at low additional cost for hybridization. The “Optimised CVT-Hybrid-Powertrain” is a full hybrid car driveline using Diesel-engine, electric motor with double layer capacitors for electric energy storage and a CVT-type transmission. Vehicle pull away is typically done by electric driving; the ic-engine is started by a fast ratio change of the CVT-transmission without additional starter.

During a special scientific project (SFB 365), supported by the DFG, a parallel hybrid concept for passenger cars, called the Autark Hybrid, was developed, assembled and investigated. The drive line consists an electric engine supplied by a 120V-Ni/MH-battery for about 30 km electrical driving distance and a turbo diesel engine. Both engines use the same gearbox, the i2-gearbox, which is specially designed to have a wide spreading. Significant fuel savings are achieved by recuperation of kinetic energy and by avoidance of inefficient operation of the ic-engine at areas of low power demand. The results from the research project concerning fuel consumption, respectively fuel saving will be presented and discussed in this paper. The adjustment between simulation and test rig investigations shows problems by the practical realisation of operation strategy and operation mode of the powertrain elements. As result smaller fuel savings can be realised than predicted.