The swivel is used to provide hydraulic oil and on
rier. The swivel is located at the centerline of rotation
some models air pressure from the carrier to the
of the superstructure. The swivel consists of a case, a
superstructure or from the superstructure to the car-
spool, and seals.
THEORY OF OPERATION
All oil or air is routed into the spool portion of the
swivel. Each channel is separated by a series of teflon
swivel where, through a series of internally drilled
and O-ring seals that prevents transfer of oil and
pressure. Return flow from the crane functions is
passages, the oil or air is transferred to a circumfer-
ential channel on the spool exterior. This channel
accomplished in the same manner through another
corresponds with a mating port on the barrel of the
set of ports.
CLEANING AND INSPECTION.
Clean the spool and barrel with a suitable sol-
vent and dry with compressed air.
Any maintenance requiring disassembly
Check the spool and the inside of the barrel for
of the swivel should include replacement
scratches, grooves, scoring, etc. If any grooves have
of all seals and rings.
developed with a depth exceeding 0.005-inch
Remove the bolts securing the center post plate
(0.1270 mm), the unit should be replaced.
and the retainer and remove the plate, retainer, and
lower thrust washer.
Withdraw the spool from the barrel.
Lubricate the spool, seals, and rings with hy-
draulic oil or STP.
Place the spool on a clean work surface in a
dust-free area and block the spool to prevent move-
ment during disassembly.
When install new seals and rings, avoid
stretching the seals or scratching the
grooved and gland surfaces.
When removing the seals and rings, avoid
scratching the grooved and gland surfaces.
Install new seals and rings on the spool using a
Remove the seals and rings from the spool.
Proper alingnment when inserting the
Aligning the discarded seals and rings in
spool is required. Do not force the
the order of disassembly will assist with
spool into the barrel.
installation of new seals and rings.