ZF-EcoLife transmission to improve buses’ mobility

ZF Friedrichshafen AG developed the EcoLife transmission keeping in mind the increasing demands on modern city buses. The focus was on the central requirements of vehicle operators pertaining to the effi¬ciency, or the LCC (costs for operating, maintenance, repair and replacement parts). In terms of the technical require¬ments, LCC are significantly affected by fuel consumption, life span and reliability, brake and cooling systems, as well as oil change intervals. Currently, this technology, ZF-Ecolife, is available in India in the Volvo 8400 low floor CNG city Bus, which is undergoing trials in Mumbai with Brihan Mumbai Electricity Supply andTransport Undertaking (BEST). Similar trials of Volvo 8400 low floor CNG city Bus equipped with ZF-Ecolife has already been successfully run with Delhi Transport Corporation (DTC) in Delhi and Navi Mumbai Municipal Transport (NMMT) in Navi Mumbai. ZF-EcoLife has considerable advantages over manual transmissions when it comes to comfort for both the passenger and the driver: Frequent starting, maneuvering, or operation at crawling speed optimally suit the transmission application. A new technology permits a quick lockup of the torque converter - the fuel-intensive hydraulic driving phases are shortened correspondingly, which leads to lower fuel consumption. Due to the modified cooling concept, ZF-EcoLife is designed for modern engines complying with all emission standards known today. The new and extremely strong integrated CityBus retarder can be used for braking processes, so service brakes are protected and service costs are reduced as a result. Due to the precise planetary gearset, gears change smoothly; the gear spacing of the 6-speed transmission supports swift acceleration without impairing passenger comfort. The latter is even improved by the fact that transmission noise is reduced to a minimum due to the planetary gearsets' helical teeth. As a standard, the ZF-EcoLife transmissions have now also been programmed with the new topography-dependent TopoDyn Life control software. The continuously variable shifting program guarantees the transmission's optimal operation at any point of the route. This process is enabled by means of individual shift points that are calculated in line with the respective route profile and the driving resistances. 25pc higher torque, 15pc higher operating temperature, considerably higher braking force, and about five percent less fuel consumption than its predecessor: with ZF-EcoLife, public transportation authorities that want to extend their capacities in the future can likewise increase performance, economy, and passenger comfort. ZF-EcoLife aims to contribute to ‘Green Cities’ by not only lowering fuel consumption, but also reducing exhaust emissions. The helical-cut ZF-EcoLife planetary gearset clearly reduces noise for passengers in the bus and for pedestrians when the bus is driving by.