SM09-004-0
Page 3
DESCRIPTION
SWING BRAKE.
superstructure base plate, and its pinion gear (bull gear)
meshes with the ring gear of the turntable bearing to ro-
The multi-disc swing brake assembly is mounted be-
tate the turntable. The swing brake is installed on top of
tween the swing motor and the swing gearbox. The
the gearbox and the swing motor is mounted on the
brake mechanism is a disc pack that is hydraulically re-
brake. The swing motor drives the gearbox through the
leased and spring applied. The brake has one hydraulic
brake assembly. The swing gearbox utilizes double re-
port.
duction planetary gearing which results in a component
circular unit of high strength and efficiency. The round
SWING GEARBOX.
gear case with horizontal rotating gears ensures lubri-
The swing gearbox is bolted to a mounting plate on the
cant circulation.
THEORY OF OPERATION
SWING BRAKE.
allowing the turntable to be rotated.
When no hydraulic pressure is applied to the brake re-
When hydraulic pressure is applied to the brake re-
lease port, spring pressure forces the brake discs
lease port, pressure is applied to the piston which ex-
against the stators. The brake discs are splined to the
tends and compresses the springs. This allows the sta-
splined shaft and are compressed between the stators.
tors to expand and relieve the friction between the brake
The friction between the brake discs and the stators
discs and the stators, releasing the braking action and
stops rotation.
MAINTENANCE
SWING BRAKE.
Assembly.
Disassembly.
NOTE
Any maintenance involving disassem-
1. Remove the four bolts and washers from the cylin-
bly of the swing brake should include
der housing. Remove the bolts together in stages, two
the replacement of all seals and O-
turns each, so as to provide uniform release of the
rings.
spring pressure.
NOTE
Remove the cylinder head and the brake piston. Dis-
2.
card the O-rings and the backup rings.
The piston and O-rings must be clean
and lubricated with clean hydraulic
3. Remove the springs from the counterbores.
fluid prior to assembly.
4. Remove the brake discs and the stators.
NOTE
5. Tap the shaft down through the bottom of the brake
Brake discs must be clean and dry.
housing.
There should be no presence of oil on
any lining material or mating surfaces
6. Remove the oil seal.
of the stators.
