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6
National Crane
03-20-2019 Control # 613-06
6-1
NBT30H-2 SERVICE MANUAL
SWING
SECTION 6
SWING
SECTION CONTENTS
Swing Gearbox and Brake . . . . . . . . . . . . . . . . . . . 6-4
Disassembly and Assembly Instructions. . . . . . . . 6-4
Tools Required . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4
Gearbox Disassembly. . . . . . . . . . . . . . . . . . . . . . 6-4
Input Planetary Repair . . . . . . . . . . . . . . . . . . . . . 6-4
Output Planetary Repair . . . . . . . . . . . . . . . . . . . . 6-4
Pinion Shaft Repair . . . . . . . . . . . . . . . . . . . . . . . . 6-5
Case Assembly Repair . . . . . . . . . . . . . . . . . . . . . 6-5
Gearbox Assembly . . . . . . . . . . . . . . . . . . . . . . . . 6-5
Swing Brake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
Disassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
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. . . . . . . . . . . . . . . . . . . . . . . . 6-8
Torque Values . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-10
Bearing Clearance . . . . . . . . . . . . . . . . . . . . . . . . . 6-10
Bearing Replacement . . . . . . . . . . . . . . . . . . . . . . 6-11
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-11
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-12
Slew Potentiometer Adjustment. . . . . . . . . . . . . . 6-13
DESCRIPTION
The purpose of the swing system is to allow the crane turret
to rotate on top of the frame. The NBT30H-2 swing system
provides 410 degree rotation.
The swing system consists of a hydraulic joystick controller,
directional control valve, swing drive gearbox, swing motor,
and swing brake. The maximum rotation is 2.0 rpm. The
swing brake is automatically applied when the control lever is
moved to the neutral position.
THEORY OF OPERATION
Swing Drive
The hydraulic power for the swing drive (Figure 6-1) is
supplied by the hydraulic piston pump. Oil flows from the
pump to the main directional control valve.
When the hydraulic joystick controller is positioned to either
right or left swing, the flow through the control valve is
directed to the swing motor and the turret rotates in the
desired direction. Shifting the control to neutral applies the
brake stopping the turret.
Swing Brake
The swing brake is spring applied and hydraulically released.
Hydraulic pressure for the swing brake control is supplied by
the swing control valve. Moving the swing control lever off
neutral releases the swing brake and starts the swing motor.
Moving the swing control lever back to the neutral position
stops the swing motor and engages the swing brake.
Summary of Contents for National Crane NBT30H-2
Page 1: ...Service Manual National Crane NBT30H 2 ...
Page 2: ......
Page 40: ...1 30 03 20 2019 Control 613 06 INTRODUCTION NBT30H 2 SERVICE MANUAL ...
Page 92: ...ELECTRIC SYSTEM NBT30H 2 SERVICE MANUAL 3 24 03 20 2019 Control 613 06 ...
Page 110: ...BOOM MAINTENANCE NBT30H 2 SERVICE MANUAL 4 18 03 20 2019 Control 613 06 ...
Page 132: ...SWING NBT30H 2 SERVICE MANUAL 6 14 03 20 2019 Control 613 06 ...
Page 142: ...OUTRIGGERS NBT30H 2 SERVICE MANUAL 7 10 03 20 2019 Control 613 06 ...
Page 158: ...LUBRICATION NBT30H 2 SERVICE MANUAL 8 16 03 20 2019 Control 613 06 ...
Page 190: ...SCHEMATICS NBT30H 2 SERVICE MANUAL 10 2 ...
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