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CAPITAL EQUIPMENT NEWS
APRIL 2015
7
CONSTRUCTION
LIEBHERR WHEEL LOADER
with power-split transmission
T
his new driveline concept has been
applied to Liebherr’s largest wheel
loader, the L 586, which has a tipping
load limit of approximately 20 tonnes.
The continuously variable power-split trans-
mission is a combination of mechanical and
hydrostatic drivelines. The diesel engine’s
power output is divided between the two
sections of the driveline, and recombined
where they come together. This principle
reduces energy transmission losses and
increases efficiency. Liebherr’s transmis-
sion and its own electronic control system
achieve an additional reduction in power
transmission losses.
The electronic transmission control system
ensures that the highest practicable ratio is
selected and allows the diesel engine to run
at a lower speed, which in turn keeps fuel
consumption down to a minimum.
The combined effect of the two halves of
the transmission is increase practical per-
formance in all stages of the work process.
When driven slowly, or when picking up
material, the wheel loader is largely driven
through the hydrostatic transmission. As
speed increases, or during lengthy work
cycles, the proportion of power transmitted
mechanically increases. Low internal losses
in the mechanical driveline are the key to its
high efficiency.
The continuously variable transmission has
the same functional principle in forward and
reverse, so that top speed and efficiency
level are identical in either direction.
With this new concept, which it is planned
to be adopted for the complete range of
large Liebherr wheel loaders, Liebherr has
combined the well-proven function of the
hydrostatic transmission with the efficiency
benefit available from a mechanical drive-
line. Compared with wheel loaders that have
a conventional driveline, Liebherr wheel
loaders with the power-split combined hy-
drostatic and mechanical transmission use
less fuel but are none the less capable of
higher load handling performance.
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