A NEW PROTOTYPE articulated bus “impressively demonstrates” system solutions to simplify the transition to electric-powered city buses, according to commercial vehicle driveline and chassis technology specialist ZF, recently.
The 18-metre ‘artic’ bus is equipped with two of the “proven” AVE 130 electric portal axles, with a total of four motors providing powerful thrust.
As the company explains, stricter emissions limits and the public debate on fine dust pollution are putting pressure on public transport operators to reduce emissions, meaning bus manufacturers are investing resources into system integration and even more on development.
In order to make the transition to local zero-emission city buses and low-emission logistic transport trucks as easy and flexible as possible, ZF is providing commercial vehicle manufacturers with technology and systems expertise, it states.
The company offers its AVE 130 electric portal axle and the new CeTrax electric central drive for city buses, acting as a one-stop shop for all the components required, says ZF. This means manufacturers can choose conventional low-floor and high-floor platforms, as well as low-entry buses for electrically powered models, which makes the electrification of vehicle fleets more economical and convenient, it adds.
In long-haul transport logistics and coach application, electric drives are no longer limited to being a fanciful idea; in fact, the hybrid version of the ZF TraXon commercial vehicle transmission exhausts previously unused power savings potential at maximum output, the company says.
ZF says it provides OEMs with expertise during this transition.
THE AVE 130
Offered in a more complete package, it includes advanced inverters, drive control and full power electronics all fully integrated. This guarantees optimal energy efficiency – and a larger range, ZF claims. For sufficient power, a standard articulated bus only needs one driven AVE 130 electric portal axle.
In principle, the installation space required for the AVE 130 is about the same as that of a conventional portal axle. For manufacturers, this means major cost savings because they do not have to develop their own chassis platforms for electric mobility solutions, the company says.
The AVE 130 can be combined with most conventional power sources, including batteries, supercaps, fuel cells or even overhead lines. It is also suitable for serial hybrid and plug-in versions. This gives OEMs and public transport operators flexibility when selecting the power supply, it states.
Standardised high-volume components and maintenance-friendliness “rounds off the overall package” of the ZF AVE 130 electric low-floor portal axle.
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PLUG-AND-DRIVE CETRAX
As a system solution for low-floor and high-floor buses, CeTrax is built on a plug-and-drive approach, so it can be integrated into existing vehicle platforms without having to make major changes to the chassis, axles, statics or differential, it’s claimed.
ZF is therefore turning to manufacturers that plan to switch from existing conventional models to electrically powered model, as part of their platform strategy.
CeTrax is configured with a maximum output of up to 300kW and a maximum torque of 4,400Nm. It is intended above all for challenging bus applications and offers considerable weight advantages, as well as outstanding efficiency, says the company.
Since the system package also covers drive control and inverters, manufacturers get an optimally fine-tuned total solution when it comes to performance, efficiency and service life. OEMs can also save time and money because ZF also handles the homologation and testing of the drive system.
PARALLEL HYBRID
The TraXon Hybrid, equipped with an electric motor positioned between the combustion engine and the transmission, allows hybrid functions in heavy commercial vehicles.
One feature particularly attractive for many applications is that in generator mode, the hybrid module can also supply power to other units, such as during refrigerated transports.
In addition to being installed in trucks, the TraXon Hybrid is also ideal for coaches, where the hybrid drive can offer the same advantages, ZF states.
ABOUT ZF
ZF is a leader in driveline and chassis technology, as well as active and passive safety technology, it states. The company has a workforce of 146,000 with approximately 230 locations in some 40 countries. In 2017, ZF achieved sales of €36.4 billion and, as such, is one of the largest automotive suppliers worldwide.