With its new, purely electric plug-and-drive solution, automotive supplier ZF is driving the development of locally emission-free public transport. The latest evidence comes in the form of ZF's innovative city bus test vehicle. It is propelled by the new CeTrax electric central drive, which is suitable for both low-floor and high-floor applications. The drive was unveiled for the first time in 2016. Now, just one year later, the development team in Friedrichshafen has implemented a CeTrax application on the road. Other ZF solutions for electric buses include the AVE 130 electric portal axle and TraXon Hybrid. The portfolio is on show at the Busworld 2017, the key trade show for city buses and coaches.

"The CeTrax central drive can be retrofitted into existing vehicle platforms without any larger modifications to the chassis, axles, statics or differentials," says Dr. Jochen Witzig. He is responsible at ZF for bus transmission system development. "Vehicle manufacturers thus save on development and installation costs. We’re the perfect partner when they want to use electric drives in addition to their conventional engines within the same platform strategy. CeTrax has the potential to really jump-start electromobility."

Powerful, flexible and comfortable
With a maximum output of 300 kW and a maximum torque of 4,400 Nm, CeTrax packs the same power as conventional engines. The bus accelerates from standing without any torque interruption, so passengers don't notice a thing. Comfort is also ensured by much lower chassis vibrations plus a quieter ride compared to conventional engines.

The fact that CeTrax can be combined with single rear drive axles and conventional low-floor axles means it can be installed in low-entry buses and low-floor buses of all sizes. Compared to other solutions, ZF's central drive provides clear weight advantages, high performance and excellent efficiency. This is down to the seamless engineering over the entire driveline and an innovative e-motor layout. The new electric drive, with its climbing ability of 25 percent, can surmount all but the steepest hills and is therefore suited to urban terrain.

Record time to market
CeTrax was presented for the first time at the 2016 Commercial Vehicle IAA in Hanover. So it took just under a year to adjust and install the concept into a ZF test vehicle. That's a prime example of the lean, dynamic development process ZF has made its own. It shows how the company not only reacts quickly to the market and technological developments, but is also actively driving electromobility.

ZF offers e-mobility solutions for further bus applications
Also available from ZF are other e-mobility solutions. Extra flexibility comes from the AVE 130 electric portal axis which can drive a range of bus types and also offers massive tractive power. Then there's TraXon Hybrid with the electric motor located between the combustion engine and the transmission. It adds hybrid functionality to heavy commercial vehicles such as coaches and trucks.