How to Deal With the Tower Crane Drum Wire Rope Arrangement?

The pick-up device is an important part of the crane. It is a device that connects materials with the crane for lifting and transporting materials by lifting, grabbing, sucking, clamping, supporting or other methods. Depending on the type, form, and volume of the materials being lifted, the retrieval devices used are also different.

The lifting mechanism of the tower crane uses a drum to wind and release the wire rope to lift materials. The use of a folding drum can improve the arrangement of multi-layer wire ropes on the drum and extend the service life of the wire rope. However, uneven arrangement may still occur due to unreasonable roll settings or other reasons.

Reel wire rope is not arranged neatly

1. The deflection Angle of the wire rope is too large

The center line between the flange on both sides of the drum must be aligned with the fixed pulley. Under this premise, the Angle between the wire rope from the reel to the first fixed pulley (that is, the Angle of the wire rope) should be between 0.5° and 1.5°. If the distance between the reel and the first fixed pulley is 20m, the distance between the wire rope and the middle of the reel should not be greater than 520mm, that is, the distance between the flanges on both sides of the reel should not be greater than 1040mm. If the wire rope deflection Angle is too large, it will cause the wire rope to be arranged on the drum.

2. Insufficient pre-tightening force of wire rope

For multi-layer wire ropes wound on drums, the first layer of wire ropes must have sufficient pre-tightening force when arranged. Only after the first layer is arranged tightly can the remaining layers of wire ropes be arranged neatly. If the first layer of wire ropes is wound without load when arranged, the pre-tightening force will be insufficient. After being squeezed by the second layer of wire ropes, it is very easy to cause local bulges and crushing of the wire ropes, thus damaging the wire ropes. The pretightening force of the drum arrangement wire rope should be about 10% of its rated load.

3. There are deviations in roll processing

If there is a deviation in the drum itself, especially if there are defects in the cooperation between the wire rope climbing platform on the side flange of the drum and the transition between the wire rope layers, it will cause rope sinking and rope climbing problems when the wire ropes are arranged, resulting in uneven arrangement of the upper wire ropes.

Solutions

Among the three reasons for the uneven arrangement of the drum wire ropes, the first and second reasons are easier to deal with. The following is an in-depth analysis of the more difficult to deal with rope sinking or rope climbing phenomena in order to completely solve the problem of uneven arrangement of the wire ropes.

1. Climbing platform

For a drum that is wound with multiple layers of wire rope, the wire rope needs to climb from the lower layer to the upper layer. Before climbing, whether the lower wire ropes are arranged neatly will directly affect the normal arrangement of the upper wire ropes. According to actual usage conditions, the key to achieving normal climbing of the wire rope is the wire rope climbing platform. The external dimensions of the climbing platform must be well coordinated with the winding of the wire rope to ensure that the multi-layer wire ropes are arranged neatly.

Depending on the diameter of the wire rope, the design dimensions of the climbing platform are also different and should be modified according to the actual situation. As the use time of the steel wire rope increases, its diameter will decrease, and the cooperation between the steel wire rope and the climbing platform will change. When the steel wire rope is wound, it is easy to cause misalignment. This is because under heavy load, the upper wire rope will squeeze into the lower wire rope under the action of pretightening force, causing increased wear of the wire rope. If the diameter of the wire rope becomes thinner, it should be replaced with a new wire rope of the same specification.

2. There is an error in the distance between drum flanges

The uneven arrangement of the wire ropes is directly related to the width error inside the drum flange. If there is an error in the inner width of the drum flange, the wire rope will not be arranged neatly.

According to the size of the drum and the diameter of the wire rope, measure whether it meets the standard proportional relationship. Then, according to the actual arrangement of the wire rope, find out the cause of the alignment deviation, and choose grinding or surfacing methods to repair the drum flange.