Steel Wire Rope Hoist
Fracture Analysis of Steel Wire Rope Hoist
- Stress characteristics of steel wire rope : wire rope force complex. When the load, the wire rope in the tensile stress, bending stress, extrusion stress and wire rope twist when the residual stress. When the wire rope around the pulley, by the alternating stress, so that the metal material fatigue, and ultimately due to wire rope and rope slot, wear and tear between the rope broken, the test shows:
(1) The bending radius of the wire rope has a great influence on the wire rope. because the bending deformation of the steel wire is increased and the bending stress also increased when the diameter of the sheave is reduced. Therefore, the wear of the steel wire is accelerated, the fatigue damage is accelerated and the life of the wire rope is shortened.
(2) wire rope around the sheave, the rope and the rope contact surface pressure and relative sliding, so that the wire rope wear broken wire, the greater the contact stress, broken wire more quickly.
(3) point contact with wire rope, due to the contact stress between the wire, the cross of the wire has increased the lateral pressure, the strength loss than the line contact type, anti-fatigue performance is poor, so the line contact wire rope point of contact with long rope life.
(4) When the wire rope between a twist between the number of broken wire to reach 10% of all the wire, continue to use, rope broken wire rate significantly accelerated, short-term there is broken stock.
(5) When other conditions are the same, the higher the safety factor of the selected wire rope, the longer the service life.
2, the reasons for the broken wire rope. To sum up, the main reason for the broken wire rope is overload and wear. It is related to the number of times the wire rope is wound on the pulley and the drum, and every time the wire is wound, the wire rope is produced by a straightening process. This is one of the main causes of damage to the wire rope. Then the broken wire is also related to the diameter of the pulley it passes through the pulley. The smaller the diameter of the pulley or reel, the more severe the bending of the wire rope, and the more fragile the ring. Therefore, the ratio of the diameter of the pulley (roll) to the diameter of the wire rope is generally required to be greater than 20-30. In addition, the broken wire rope also with the type of work, the use of the environment (high temperature, corrosive gases), custody, use of the situation. The wear of the wire rope, the wear between the reel and the pulley, and the wear between the wire rope. To reduce the wear and tear, the key lies in the lubrication of the rope, if done so that the rope in a normal state of lubrication, will inevitably make the wear and tear of the wire rope to a minimum.