AS-Tronic replacement expected to debut in coaches later in 2018; modular nature will see an optional bolt-on hybrid unit follow for a modest zero emission range but no dual clutch in the passenger sector
ZF has revealed more details of its forthcoming 12-speed overdrive Traxon automated manual transmission. It will replace the AS-Tronic this year and will later offer a limited engine-off capability in coaches via an optional bolt-on hybrid unit.
Traxon is lighter than the AS-Tronic. It has been designed for significantly heavier duty cycles than its predecessor, and it is capable of 60% more gearshifts and 50% more clutch actuations.
“Those increases are not due to a single modification; we have made many internal changes,” says Dr Jochen Witzig, head of ZF’s business unit for coach and bus axles and transmissions.
He adds that Traxon’s life between overhaul is longer than the AS-Tronic’s. That and a slight increase in efficiency contribute to a lower total cost of ownership, while noise emissions are cut by 35%. Gearshifting in particular is much quieter.
Traxon will be supplied as standard with the Intarder 3 that delivers up to 600kW of brake force. The AS-Tronic’s external breather has been dropped and Traxon also comes with an inclinometer.
Of particular relevance to coach applications is Traxon’s modularity. The optional bolt-on hybrid unit will run off batteries charged during motorway cruising and it will deliver a modest zero-emission range.
Early trials of the hybrid module are underway, and ZF plans to take the concept to field use by Q3 2019. Full production is expected early next decade. “Momentum behind the hybrid package has increased thanks to the political landscape in cities,” adds Dr Witzig, who says that while Traxon also has a bolt-on dual clutch module, it will not be available in coach applications.
ZF has also revealed that it will later supply a direct-drive Traxon in conjunction with an optimised drive axle. That, promises Dr Witzig, will deliver up to a 4.4% increase in fuel economy over existing gearbox and axle combinations.
