Document 57.4402.8200 - 1st Edition 03/2007 INDEX
GYRO 4020 - 4518
INTRODUCTION
ii
DESCRIPTION OF THE MACHINE OPERATION
The oil-pressure system of this machine consists of two
macro sections, namely turntable and undercarriage,
corresponding to the machine's main parts. From an oil-
pressurepointofview,thesetwosectionsareconnected
with one another by the 13-way hydraulic rotary joint
(9).
The source of mechanical energy of this machine is
a Deutz turbo-compressed diesel engine (1), model
BF4M2012, which supplies 74.9 kW at 2300 rev/min
and with a max torque of 390 Nm at 1500 rev/min.
On the ywheel side of the engine, and connected to
this engine by a Technodrive coupler with elastic joint
and with a 1-to-1 ratio, there is a Linde closed-loop
pump for hydrostatic drives, model HPV 75-02RE112V
(2) with electroproportional adjustment valves.
The max displacement of this swashplate pump is 75
cm3and the max calibration pressure is 445 bar.
This pump is used to supply hydraulic power under form
of pressure and ow rate which is then used for moving
the machine.
This pump is used to supply hydraulic power under form
of pressure and ow rate which is then used for moving
the machine.
On the through-shaft of such drive pump there is a
Bosch-Rexroth variable displacement piston pump
with swashplate suitable for open lopp circuits, model
A10VO45DFR (3), equipped with ow and pressure
control valve.
Thedisplacement of this pump is45 cm3. The function of
this pump, through the “load sensing” priority valve (6) is
to provide hydraulic power, under form of pressure and
ow rate to the steering cylinder of the machine (priority
sideofthevalve)andtothetelescopicboomandslewing
turntable circuits (secondary side of the valve).
This "load sensing" pump is adjusted through an
adequate piloting line which provides the pump a
pressure signal corresponding to the max load of all the
users fed by this pump.
Betweenpump(3)andpriorityvalve(6),aone-wayvalve
(5) is placed to avoid that oil at pressure, produced by
the power-driven emergency pump (48), may escape
from pump (3) when this is stopped.
The assembly of the two pumps involves they have
a rotation velocity equal to the speed of the diesel
engine.
A third Casappa xed displacement gear pump suitable
for open loop circuits (4) with a displacement of 25 cm3,
is installed on the PTO of the engine located on the
distribution side.
This pump feeds the servo-assisted braking system
(35) and the hydraulic motor (42) of the heat exchanger
fan (43) used to cool down the diesel engine and the
hydraulic circuit.
