WIRE ROPE INSTALLATION AND MAINTENANCE
Folio 931-10
5. Replace worn or damaged bearings.
6. Replace grooved drums that allow one wrap of wire rope
to contact next wrap as rope spools onto drum.
NYLON SHEAVE INSPECTION
Inspect nylon sheaves WEEKLY.
Nylon sheaves cannot be accurately inspected using
conventional methods such as sheave gauges.
Manitowoc recommends that nylon sheaves be measured
for excessive tread diameter wear.
Due to the characteristics of nylon sheaves, the nylon
material will actually move to better support the wire rope as
the sheave wears normally.
NOTE: Depending on the type of wire rope used, It is
normal for nylon sheaves to show the wire rope
print.
Do not remachine nylon sheaves
.
Nylon sheave properties will be degraded in temperatures
above 140° F.
1. Inspect nylon sheaves for excessive wear, physical
defects, or damage (chips, cracks, broken flanges, flat
spots in grooves, sheaves walking off of hubs, etc.).
Replace worn or damaged sheaves.
2. Inspect sheaves to verify they do not contact another
sheave or structural plate work. Repair or replace worn
or damaged sheaves.
3. Inspect sheaves to verify they have not separated and
“walked off” steel inserts or bearings as shown in Figure
15. Maximum sideways displacement is 1/8 in. (3 mm).
Replace worn or damaged sheave assembly.
4. Verify that sheaves turn freely. Wire rope may have to be
loosened to perform this inspection. Repair or replace
worn or damaged sheave.
5. Inspect sheave wear at locations E in Figure 16.
Measure at three positions to check for uneven wear.
Wear must not exceed limits given in table. Replace
worn or damaged sheave.
6. Most of Manitowoc’s nylon sheaves have sealed
bearings that do not require lubrication.
Due to application and design variations, it is not
possible to give specific grease repacking intervals or
life expectancy of components.
We recommend that nylon sheaves be inspected
weekly. For recommendations on specific applications,
please contact Manitowoc’s CraneCARE Service
Department.
When a nylon sheave is overhauled, repack the bearing
with N.G.L.I. EP #2 grease,
NOTE: For some sheaves, the seals are an integral part of
the bearing. Therefore, if a seal is damaged during
repacking, the complete bearing may have to be
replaced.
DISTRIBUTING WIRE ROPE WEAR
Wire rope wear at the “critical wear points” can be reduced
and the life of the wire rope extended by moving the rope at
regular intervals so different sections of rope are subjected to
the wear points. This practice can also help correct spooling
problems and rope vibration.
To move the wire rope, cut off a piece of wire rope at the
drum and refasten it. The piece cut off should be long
enough to move wire rope at least one full drum wrap.
If the wire rope is too short to allow cutting off a piece of it,
reverse the rope end for end and refasten it.
Steel Insert
or Bearing
Nylon
Sheave
Improper
Snap Ring
Engagement
FIGURE 15
1/8" (3 mm)
Maximum Sideways
Displacement
395143
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