|
|
| |
 |
 |
|
| |
to Technical
Information Main Page |
|
| |
|
|
 |
| |
|
|
| The performance of all wire ropes depends
on the condition and sufficient dimensions of sheaves and drums. Too small
sheaves and drums will reduce the service life of a rope. This is more a
question of 'performance' rather than 'safety'. |
| |
|
| |
|
|
|
The following table is based upon
recommendations by the Wire Rope Technical Board:
|
| Construction |
|
Suggested
D/d ratio |
|
|
|
|
|
| 19x7 / 18x7 |
|
34 |
|
| 6x26 WS |
|
30 |
|
| 6x25 Filler, 6x31
WS, Compac® 626 |
|
26 |
|
| 6x36 WS, Compac®
636, Python® HS9 and Ultra |
|
23 |
|
| 8x25, Python®
Super 8 and Multi |
|
20 |
|
| Compac® 19
& 34, Python® Lift and Hoist |
|
20 |
|
| 8x36 WS |
|
18 |
|
|
|
Sheave opening angle should be 35°
to 45° for applications with fleet angles 
1.5°, for larger fleet angles use 60° opening.
Maximum rope fleet angle for general purpose ropes should not exceed 4°,
for non-rotating/rotation resistant types and Python® HS-9 and Ultra
the fleet angle should not exceed 1.5°.
Recommended Sheave and Drum Contours:
Groove radii minimum: o.53 to .535x d for new rope
Groove radii maximum: o.55 to o.56x d
Sheave Groove depth: 1.5 x d
Drum Pitch for SINGLE layer minimum: 2.065 x groove radii
Drum Pitch for SINGLE layer maximum: 2.18 x groove radii
Drum groove depth: minimum 
o.375x d for helical grooved
Hardness: As wire rope has a hardness of about 50-55 RC we recommend that
the hardness of sheaves and drums is at least 35 RC, better is 40-45 RC.
 |
| |
|
Drums |
 |
|
Multi-layer drum systems
should use Compac® or type 'V' Python® rope constructions having
a steel core. The higher fill factor of such rope constructions will offer
a greater resistance to crushing and flattening than conventional rope types.
This is particularly important for boom hoist ropes on lattice boom cranes
at the cross over point from one rope winding to the next.
Cranes equipped with multi-layer drum systems which require rotation-resistant
or non-rotating rope are best served with Compac® or Python® rope
constructions as these have a smooth outer surface allowing the rope to
better 'glide' from one winding into the next.
To further reduce drum crushing have the first rope layer wound onto the
drum with about 5-10% of the WLL and avoid that this first layer unspools
and re-spools without tension. This would cause a 'soft' bottom layer which
will flatten rather quickly. |
| |
|
|
 |
|
Compac® and Python®
ropes also help reduce strand interlocking which normally occurs at adjacent
rope wraps. This is caused by too large of fleet angles as well as is the
cause of multiple layer windings on smooth (ungrooved) drums.
Compac® and Python® ropes have a smooth and very round outer rope
surface which helps to minimize abrasive wear due to strand-to-strand contacts. |
| |
|
|
| |
|
For further information please refer to our
Catalogue 'Handling Procedures'. |
|
| |
|
|
| |
|
|
| |
|
Back to Top |
| |
|
|
