Liebherr TA 230 Litronic - Manual (Page 19)

36 // Quarrying Quarrying // 37
The retarder is a form of continuous
braking system and makes it possible to
decelerate over an extended period
without a significant loss of power. It
comprises of two opposing vane wheels
within a converter housing: the rotor,
which is connected to the vehicle’s drive
train and thus rotates, and the stator,
which is permanently fixed to the converter
housing. When needed, oil is fed into the
converter housing and accelerated by the
rotor. The centrifugal force presses the oil
into the stator, braking the rotation of the
oil and feeding this back into the rotor.
The result is that the rotor and the
connected drivetrain are braked.
This allows safe braking, especially on
long downhill stretches, relieving the load
on the service brake. Thanks to the
retarder, the service brake remains cold.
This prevents fading due to heat buildup,
while retaining the full braking effect of the
service brake. Besides this important
safety aspect, the service life of the service
brake is also substantially prolonged by
the active use of the retarder.
Fundamentally, all retarders work in a
similar way to this. However, the retarder
in the TA 230 articulated truck has a
number of special features.
Driver, load and gradient have a
fundamental influence on the brake
performance. If there are only fixed retarder
levels, the retarder will always provide
either too much or too little braking effect.
Taking a look at the dashboard of the
TA 230, the small lever on the left of the
gear lever is conspicuous. This lever is
used to freely vary the retarder setting from
0 % to 100 % efficiency. That way, the
required braking effect is always achieved.
There is no need for compromise.
As soon as the driver takes his foot off the
accelerator pedal, the required retarder
setting immediately takes effect on the
last angle setting of the accelerator pedal.
By contrast to other machines, there is no
time lag in the start of deceleration. In
addition, the braking effect of the retarder
is also supported by the engine brake.
This brake is upstream of the retarder and
becomes effective slightly earlier. The
engine brake in the TA 230 is especially
effective, because alongside the engine
brake flap the compression of the piston
is also exploited optimally for the braking
effect. This patented process increases
the braking effect by about 40 % compared
to that of a conventional engine brake.
Together, the freely variable control of the
retarder and the high efficiency of the
engine brake provide an enormous
advantage with respect to safety, efficiency
and comfort.
The retarder on the TA 230 Litronic –
braking without compromise
Safety always comes first. Productivity, efficiency and comfort are not necessarily contradictory. The freely
adjustable retarder in the TA 230 Litronic impressively demonstrates how these requirements can be reconciled.
Trends
The engine brake in the TA 230 Litronic
dump truck has 40 % higher braking
effect compared to conventional brakes.
The lever on the far left
allows the retarder setting
to be freely adjusted.