Manitowoc National Crane NBT40 Series, Руководство по обслуживанию

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BOOM MAINTENANCE NBT40 SERVICE MANUAL
4-6
Published 8-01-2017 Control # 287-11
Four Section Top/bottom Pad Replacement,
Assembled Boom
Inspect top and bottom wear pads periodically for signs of
abrasion or excessive wear.
Excessive wear is wear in excess of 3/16 in from original
thickness (1st, 2nd and 3rd stage bottom tip pads are
31.8mm (1.25 in) thick, and 2nd and 3rd stage top pads are
28.6mm (1.125 in) thick, 4th stage top pads are 11.6mm
(.45 in) thick or uneven wear such as the outside edge of the
pad worn in excess of 3/32 in deeper than the inside edge of
the pad. If any of these conditions are found, the top and
bottom pads may be replaced without disassembly of the
boom. Also, if the boom extension operates erratically or
d u r i n g r e p l a c e m e n t o f t o p a n d b o t t o m p a d s , i t i s
recommended that the lubricating plugs in the wear pads
also be replaced with new plugs. These new lube plugs
initially extend 0.06 above the pad surface and will wipe a
long lasting coating of lubricant onto the boom sliding
surface.
Top Pad Replacement
NOTE: All wear pads must be tagged, inspected and
r e a s s e m b l e d e x a c t l y a s t h e y h a v e b e e n
removed unless doing a complete overhaul.
1. Retract the boom completely, then extend the boom
approximately 13.50 in (4.50 in per stage) so that upper
wear pads on 3rd stage boom are visible through holes
in the top plates of the 1st and 2nd stage booms.
2. Remove countersunk capscrews from the top base of
the 3rd stage boom wear pad retaining plates and
remove wear pad retaining plates from the 3rd stage
boom. Mark these retaining plates so they can be
reinstalled exactly as they were removed. Remove 3rd
stage boom wear pads.
3. If necessary, mark the location of the nuts and loosen
the 1/2/3 extend cables and remove them from the
mounting holes at the base of the 1st stage boom. Tie
the 1/2/3 extend cables with approximately 2 ft of wire
and allow them to slack into the 1st stage boom
removing cables from notch in 3rd stage boom pads.
4. Replace the 3rd stage boom wear pads and reinstall
wear pad retaining plates exactly as removed onto the
top plate of the 3rd stage boom. Loctite all flathead
mounting screws.
5. If necessary, reinstall the 1/2/3 extend cables into the
base of the 1st stage boom and reinstall the nuts which
secure these cables to their original location previously
marked on the threaded cable ends.
6. Extend the boom approximately 31.5 in (10.44 in per
stage) so that upper wear pads on 2nd stage boom are
visible through hole in the top plate of the 1st stage
boom.
7. Remove countersunk capscrews from the top base of
the 2nd stage boom wear pad retaining plates and slide
wear pad retaining plates towards the center of boom.
Mark these retaining plates so they can be reinstalled
exactly as removed. Remove the 2nd stage boom wear
pads.
8. Replace the 2nd stage boom wear pads and reinstall
wear pad retaining plates onto the top plate of the 2nd
stage boom exactly as removed. Loctite all flathead
mounting screws.
9. Extend the boom approximately 40.7 ft (162.75 in per
stage) so that base of the 4th stage boom passes the
hole in the side plate of the 3rd stage boom. Raise the
4th stage boom tip to relieve pressure on wear pads on
the top base of the 4th stage boom.
10. Remove countersunk capscrews from the bottom of the
top plate on the base of the 4th stage boom that attach
the wear pad retaining plates to the 4th stage boom.
11. Slide wear pad retaining plates and wear pads toward
base of boom and remove. Mark the wear pad retaining
plates so they can be reinstalled exactly as removed.
12. Replace the 4th stage boom wear pads and reinstall
wear pad retaining plates exactly as removed onto the
top plate of the 4th stage boom. Loctite all flathead
mounting screws.
Bottom Pad Replacement
1. Lower the boom until the boom lift cylinder is bottomed
out and extend the boom approximately six ft out (two ft
per stage).
2. Raise the 4th stage boom tip, until weight is removed
from the bottom pads in the 3rd, 2nd and 1st stage
booms.
3. Remove the capscrews (two in each pad) which retain
the 2nd and 1st stage boom bottom wear pads and
remove and replace pads. Reinstall capscrews, Loctite
and torque to proper tightness.
4. Remove the capscrews (two in each pad) which retain
the 3rd stage boom bottom wear pads and remove and
replace pads. Reinstall capscrews, Loctite and torque to
proper tightness
4 Section Boom Disassembly
For reference, front (tip) is sheave case end, rear (base) is
hoist mount end, left and right are viewed from rear to front.
NOTE: All wear pads must be tagged, inspected and
r e a s s e m b l e d e x a c t l y a s t h e y h a v e b e e n
removed unless doing a complete overhaul.
Steps 1 through 3 apply to a boom that is to be disassembled
with the 1st section and jib (if equipped) left on crane. all
Reference Only