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6
National Crane
Published 8-01-2017 Control # 287-11
6-1
NBT40 SERVICE MANUAL
SWING
SECTION 6
SWING
SECTION CONTENTS
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
Theory Of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
Swing Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
Swing Brake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
Swing Gearbox And Brake . . . . . . . . . . . . . . . . . . . . . 6-4
Removal and Installation . . . . . . . . . . . . . . . . . . . . . . 6-4
Disassembly & Assembly Instructions. . . . . . . . . . . . 6-4
Tools Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4
Parts Required to Rebuild . . . . . . . . . . . . . . . . . . . . . 6-4
Disassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4
Input Planetary Repair. . . . . . . . . . . . . . . . . . . . . . . . 6-5
Output Planetary Repair . . . . . . . . . . . . . . . . . . . . . . 6-5
Shaft Repair. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5
Case Assembly Repair . . . . . . . . . . . . . . . . . . . . . . . 6-5
Unit Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5
Swing Brake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
Disassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8
Swing Bearing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-8
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-8
Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-8
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-8
Torquing Swing Bearing Bolts. . . . . . . . . . . . . . . . . . .6-8
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-8
Swing Bearing Bolts . . . . . . . . . . . . . . . . . . . . . . . . . .6-9
Tools Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-9
Bearing Clearance. . . . . . . . . . . . . . . . . . . . . . . . . . . .6-11
Bearing Replacement . . . . . . . . . . . . . . . . . . . . . . . . .6-12
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-12
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-13
Slew Potentiometer Adjustment . . . . . . . . . . . . . . . .6-14
Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-14
Swing Lock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-14
DESCRIPTION
The purpose of the swing system is to allow the crane turret to
rotate atop the carrier frame. The NBT40 swing system provides
full 360 degree rotation in both directions and is equipped with
free swing capabilities. With free swing, the SWING BRAKE
switch is in the OFF position and the turret swings freely after
the SWING control lever is released and coasts to a stop.
NOTE:
When equipped with a radio remote control, the
swing brake is automatically applied whenever the
swing control lever is in the neutral position.
The swing system consists of a hydraulic remote controller,
directional control valve, swing drive gearbox, swing motor,
swing brake, and swing brake pedal. The maximum rotation is
2.0 rpm. The swing control lever is used to slow and stop the
swing by moving the control lever to the opposite direction of the
swing. The swing brake pedal is used to keep the turret parked
in position.
THEORY OF OPERATION
Swing Drive
The hydraulic power for the swing drive (Figure 6-1) is supplied
by the PTO driven axial piston hydraulic pump. Oil flows from
the pump, through swivel port #3, to the main control valve.
When the hydraulic remote control is positioned to select right or
left swing, the flow through the control valve is directed to the
swing motor. If the SWING BRAKE selector switch is in the OFF
position, the turret rotates in the desired direction. Shifting the
control to neutral allows the turret to coast to a stop. Shifting the
control to the opposite directions powers the turret to a stop.
Depressing the swing brake pedal holds the turret in position.
Reference Only
Summary of Contents for National Crane NBT40 Series
Page 1: ...Service Manual National Crane NBT40 Series R e f e r e n c e O n l y ...
Page 2: ...R e f e r e n c e O n l y ...
Page 216: ...SCHEMATICS NBT40 SERVICE MANUAL 10 2 THIS PAGE BLANK R e f e r e n c e O n l y ...
Page 218: ...NBT40 SERVICE MANUAL APL 2 THIS PAGE BLANK R e f e r e n c e O n l y ...
Page 219: ...R e f e r e n c e O n l y ...
Page 220: ...R e f e r e n c e O n l y ...