Tadano TT-800XXL1, Service Manual

Page: 73 / 267

D-1. D-1.
Swing System
1
WD02-0230E
Swing System
1 . Description of the units
1 . 1 Swing drive unit
1 . A hydraulic motor with wet-type brake and the
double reduction planetary gear is integrated in
the unit. This unit converts the pressurized oil
delivered from the pump into the low-speed
high-torque turning force to employ it for driving
the swing structure.
1 .2 Hydraulic pilot control valve
1 . It shifts the flowing direction of the pressurized oil
by the pilot pressure in order to control the
rotating direction of the hydraulic swing motor.
2. The proportional valve provided for swing slow
stop stops the swing movement gradually.
1 .3 Solenoid valve
(swing free/lock select)
1 . When it is energized, it delivers the pressurized oil
to the brake cylinder of the swing drive unit to
release the swing brake.
1 .4 Select valve (dolly)
1 . To travel with a dolly hitched to the rear of the
carrier, it is required that the hydraulic circuits for
the boom elevating cylinder and swing motor be
free so that the boom can follow the movements
of the dolly while travelling.
2. Swing slow stop
2. 1 Condition for slow stop
Slow stop function is activated when the crane is
in the condition marked with a circle.
Swing stop
Not cancelled
Slow stop function
Override
OFF
Override
ON
Cancelled
Stop by swing range
restriction
O × ×
2.2 Control element
The current value and starting angle of deviation
outputted to the solenoid proportional valve for
slow stop are limited by the following conditions:
(Applicable to stop by range restriction)
• Boom length and lift status (full retraction, full
extension, single top lift, jib lift)
• Swing speed (The angular velocity is
automatically calculated inside the AML.)
Starting angle of deviation
Swing
speed Boom fully
retracted
Boom fully
extended
Single top
lift
Jib lift
(2-stage)
High
speed
35°- 45° 40°- 50° 40°- 50° 40°- 55°
Low
speed
20°- 40° 25°- 45° 25°- 45° 35°- 45°
Start point
Stop point
Angle where stop control
starts during left swing.
Determined by AML, which
automatically calculates
outrigger extension width,
boom input conditions, and
swing speed.
Deviation angle at start of control
(Based on following data, regardless of boom length)
IWD02-0 1 4 1 E0 1