Tadano TT-800XXL1, Service Manual

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B-1. B-1.
Hydraulic Power Generating System
1
WB02-0270E
Hydraulic Power Generating
System
1 . Functions of units
1 . 1 Hydraulic pump
This pump consists of double variable
displacement piston pump and double gear pump.
Pump A
1 is used for the winch circuit, pump A2
for the boom telescoping, boom elevation and
winch circuits, pump A3 for the swing circuit, and
pump A4 for the winch accumulater, remote
control, swing brake release, jib setting, c/w
mounting/dismounting, oil cooler drive moter and
air conditioner (option) circuit.
1 .2 Rotary joint
The rotary joint allows pressurized oil from the
hydraulic pump and current from the battery to be
sent to the swing table, and at the same time
allows operation of the accelerator from the swing
table.
1 .3 Hydraulic pilot control valve
By moving the spool utilizing the external pilot
pressure from the remote control valve, it changes
the direction of the pressurized oil introduced from
the port P into the hydraulic cylinder or inlet/outlet
port of the hydraulic motor and controls the oil
flow by changing the displacement of the spool.
1 .4 Sequence valve
1 . This valve incorporates a sequence valve and a
reducing valve.
2. The reducing valve regulates the oil pressure
below the specified value; the sequence valve
regulates it above the specified value.
1 .5 Flow control valve
This valve is installed on the A4 pump circuit and
ensures fixed amount oil flow to the hydraulic
motor for the air conditioner and oil cooler, as well
as prevents troubles caused by pulsation.
1 .6 Solenoid valve (for venting pressure for
remote control)
It supplies and vents the pilot pressure for the
remote control. While the solenoid valve is
deenergized, the oil flow to the remote control
valve is shut off, making crane operation
impossible.
1 .7 Hydraulic motor (for oil cooler)
1 . If the crane is used under high load for a long time
in summer, the hydraulic oil temperature will rise
over 70°C (
1 58°F), leading to oil deterioration
such as oxidation and reduced oil viscosity that
can cause leaks in the pump and motor and
reduce volume capacity.
2. To prevent such troubles, the returned oil is
force-cooled (while the motor is driven by the oil
delivered from the A4 pump). (The forced-cooling
operation is available also during traveling
because the A4 pump always delivers oil while the
engine is running.)
1 .8 Solenoid valve (for oil cooler)
It serves to start/stop the hydraulic motor which
drives hydraulic oil cooler. When the oil cooler is
functioning, it is energized and drives the
hydraulic motor.