Up the curtain on the AxTrax 2 electric axle by ZF (with series production to begin in 2025)

ZF showcased its new AxTrax 2 LF electric portal axle for low-floor city buses. The series production of AxTrax 2 LF is set to commence in 2025.

The new axle represents ZF’s latest e-Mobility evolution, offering improved performance to further support the commercial vehicle industry’s transformation towards a more sustainable future. The group, as presented during a technical briefing held at Busworld, expects 63 per cent of new city buses to be electric in 2025, and becoming 83% in 2030 and 90% in 2035.

ZF new AxTrax axle in two versions

ZF’s new AxTrax 2 LF low-floor electric axle comes with two stand-alone silicon carbide (SiC) inverters and a high-performance electric control unit, offering an all-inclusive e-drive system for city buses.

Highly efficient and powerful, AxTrax 2 LF is available in two variants. These offer continuous power outputs of 260 kW and 360 kW and peak torques of 22,700 Nm and 37,300 Nm. With the more powerful variant, it is possible to achieve a climbing ability of 20% even for articulated buses of up to 29 tons with one driven axle, the group states.

AxTrax 2 LF’s compact design “maximizes the available space for the passenger compartment or batteries, enabling passenger-friendly bus design concepts – ZF states -. Fitting a similar installation space as its predecessor AxTrax AVE, the new axle is fully compatible with ZF’s air suspension and wheel-end solutions. On the software side, AxTrax 2 LF also benefits from ZF’s extensive experience in producing cutting-edge functions such as axle condition monitoring and cyber security”.   

Offering up to 10% energy saving compared to the previous generation, the new AxTrax 2 LF offers single-speed operation making it perfectly suited for the frequent stop-start nature and relatively lower average speeds of city-bus journeys. Its new oil cooling system adapts the oil flow rate to help maximize efficiency, optimizing operating temperature and lubrication.

“Adding AxTrax 2 LF to our comprehensive range of electric powertrains is a powerful expansion of our game-changing scalable and modular e-Drive kit,” said Winfried Gründler, Driveline Systems Product Line Leader with ZF’s Commercial Vehicle Solutions division.

“AxTrax 2 LF represents the latest step in ZF’s support for commercial vehicle manufacturers towards the transition to zero emissions technologies. Whether it is complete turn-key systems or components, ZF has the one-stop-shop capabilities to help electrify manufacturers’ vehicle platforms worldwide,” added Gründler.