Technical description, Hydraulic system, Swing – Liebherr LB 20 User Manual
Page 11: Auxiliary winch, Crawlers, Control, Noise emission, Rope crowd system, Engine, Kelly winch with freewheeling
LB 20
11
Technical description
Hydraulic system
The main pumps are operated by a distributor gearbox. Axial piston
displacement pumps work in open circuits supplying oil only when
needed (flow control on demand).
The hydraulic pressure peaks are absorbed by the integrated
automatic pressure compensation, which relieves the pump and
saves fuel.
Pumps for working tools
2x 63 gal/min
Separate pump for kinematics
36 gal/min
Hydraulic oil tank
159 gal
Max. working pressure
5076 PSI
The cleaning of the hydraulic oils occurs via an electronically
monitored pressure and return filter.
Any clogging is shown on the display in the cab.
The use of synthetic environmentally friendly oil is also possible.
Swing
Consists of triple-row roller bearing with external teeth and two
swing drives, fixed axial piston hydraulic motor, spring loaded and
hydraulically released multi–disc holding brake, planetary gearbox
and pinion. Selector for 3 speed ranges to increase swing precision.
Swing speed from 0 – 3.5 rpm is continuously variable.
Auxiliary winch
Line pull effective (1
st
layer)
17.985 lbf
Rope diameter
20 mm
Line speed
0-233 ft/min
Crawlers
Propulsion through axial piston motor, hydraulically released spring
loaded multi–disc brake, maintenance-free crawler tracks, hydraulic
chain tensioning device.
Drive speed of telescopic undercarriage
0 – 1.1 mph
Track force
103,415 lbf
Width of 3-web grousers
27.6 inch
Transport width
9.8 ft
Option:
Width of 3-web grousers
31.5 inch
Transport width
11.2 ft
Control
The control system – developed and manufactured by Liebherr – is
designed to withstand extreme temperatures and the many heavy–
duty construction tasks for which this machine has been designed.
Complete machine operating data are displayed on a high resolution
monitor screen. A GSM/GPRS telematics module allows for remote
inquiry of machine data and operational conditions. To ensure clarity
of the information on display, different levels of data are shown in
enlarged lettering and symbols.
Control and monitoring of the sensors are also handled by this high
technology system. Error indications are automatically displayed on
the monitor in clear text. The machine is equipped with proportional
control for all movements, which can be carried out simultaneously.
Two joysticks are required for operation. Pedal control can be
changed to hand control.
Option:
PDE
®
: Process data recording
Noise emission
Noise emissions correspond with 2000/14/EC directive on noise
emission by equipment used outdoors.
Rope crowd system
Crowd force push/pull
67,445/67,445 lbf
Line pull (effective)
33,725 lbf
Rope diameter
24 mm
Travel
47.6 ft
Line speed
0-256 ft/min
The winches are noted for compact, easily mounted design.
Propulsion is via a maintenance-free planetary gearbox in oil bath.
Load support by the hydraulic system; additional safety factor by
a spring–loaded, multi–disc holding brake. All line pull values are
effective values. The efficiency factor of approx. 25% has already
been deducted.
Engine
Power rating according to ISO 9249, 270 kW (362 hp) at 2000 rpm
Engine type
Liebherr D 936 A7 SCR
Fuel tank
185 gal capacity with continuous level
indicator and reserve warning
Engine complies with NRMM exhaust certification EPA/CARB Tier 4i
or 97/68 EC Stage III B.
Kelly winch with freewheeling
Line pull effective (2
nd
layer)
40,465 lbf
Rope diameter
28 mm
Line speed
0-259 ft/min