ZF's AxTrax 2 LF electric axle for city buses to hit show floor at APTA EXPO 2023

Oct. 9, 2023
The AxTrax 2 LF features a compact design to help maximize the available space for batteries and enhance manufacturer’s design flexibility for the passenger compartment.

ZF's AxTrax 2 Low-Floor (LF) electric axle for city buses will be showcased for the first time publicly in North America at APTA EXPO 2023. The new axle represents ZF’s latest e-mobility solution to support the commercial vehicle industry’s transformation towards a more sustainable future. The series production of AxTrax 2 LF is set to commence in 2025.

“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 Vice President of Commercial Vehicle Driveline Systems, Americas for ZF Group Christian Feldhaus. “In addition to extending our bus technology portfolio, AxTrax 2 LF represents the latest step in ZF’s support for commercial vehicle manufacturers towards the transition to zero emission technologies. Whether it is components or complete turn-key systems, ZF has a wide range of solutions to help electrify manufacturers’ vehicle platforms worldwide.”

The AxTrax 2 LF is an axle-based, modular and integrated system, featuring a compact design to help maximize the available space for batteries and enhance manufacturer’s design flexibility for the passenger compartment. It is designed and manufactured inhouse and benefits from ZF’s extensive e-powertrain expertise. As part of ZF’s modular platform approach, the technology improves system performance and efficiency and is designed for demanding bus applications. Having 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 advanced functions such as axle condition monitoring and cyber security.

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 torque of 16,740 lb-ft and 27,500 lb-ft respectively. With the more powerful variant, it is possible to power articulated buses up to 64,000 lbs with one driven axle as a 6x2 configuration. Both models feature two integrated electric Permanent Magnet Synchronous motors, as well as two separate 800V silicon carbide inverters.

Compared to its predecessor, AxTrax 2 LF offers up to 10 percent energy saving and is well suited for the frequent stop-start nature and relatively low 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.

Orange County Convention Center
Aerial view of the Orange County Convention Center West Concourse where APTA TRANSform and EXPO will return for its 2023 event.