Australasian Bus & Coach - May 2018

(^48) ABC May 2018 busnews.com.au
SUPPLY LINES ENGINES & TRANSMISSIONS
ZF – improved
driving dynamics
T
HE ZF-ECOLIFE six-speed
automatic transmission
lives up to its reputation as
universal genius once more,
its states. Thanks to the new
start-stop function, city buses consume
up to 10 per cent less fuel. An additional
transmission variant called EcoLife Coach
is particularly suitable for higher input
torques of up to 2300Nm and therefore for
intercity and coach applications.
For sophisticated coach tours there’s
the ZF-EcoLife coach for torques
up to 2300Nm. ZF-EcoLife is the
worldwide benchmark for automatic
bus transmissions used in the most
demanding application area – the city
traffic, it’s stated. Based on this, the
technology company is expanding the
transmission family with the ZF-EcoLife
Coach version. This is specifically designed
for use in intercity buses and coaches
and for particularly demanding routes.
The torque converter in the ZF-EcoLife
Coach transmits input torques of up to
2300Nm – and thus the comparably high
performance of coach engines.
In mountain regions, for instance,
intercity buses and coaches must
frequently brake hard due to frequent
narrow bends and must then accelerate
strongly again. For this reason, many gear
changes in a short period of time are
required – just like in city traffic. This is
where ZF’s EcoLife Coach benefits from
its high efficiency and its smooth and
efficient acceleration without tractive force
interruption when changing gears. Speed
and accelerative force do not drop off
either, which has a positive effect both on
fuel consumption and noise emissions.
When driving downhill, ZF’s primary
retarder pays off: this system is the only
one that develops its braking effect
depending on the engine speed and not,
as conventional secondary retarders do,
in relation to the vehicle velocity. Thus,
the retarder also efficiently decelerates
on long downhill routes and at low bus
velocities, increasing safety and reducing
the wear of the service brakes. As a result,
combined with the innovative cooling
concept, it is possible to apply the retarder
for a very long time without reduction, and
to use it almost until vehicle standstill.
A current trend gives further reasons
why to opt for ZF-EcoLife Coach: many
coaches also drive often in cities for
long, continuous stretches of time. For
instance, when they are used as shuttles
between city hotels and the airport or for
sightseeing at the destination. In both
cases, the buses and their transmissions
have to tackle both low speeds and
frequent gear changes in stop-and-go
traffic. In this way, the ZF-EcoLife Coach
optimally combines the requirements of
coaches with the driving situation of city
buses. EcoLife Coach went into volume
production in fall 2016 and has been
continuing ever since (at MAN and Irizar,
among others). EcoLife Coach will also
go into volume production with its new
generation of engines at VDL and Van Hool
very soon.