How to choose crane wire rope Wire

　　rope is very commonly used in construction cranes, and is generally made of many high-strength steel wires. It is firstly formed by winding a single steel wire together to form a strand, then some of the strands are wound into a rope core, and then an outer strand composed of other strands is wound around the core to form a wire rope. Some imported steel wire ropes also contain a plastic ferrule, which is usually covered on the rope core by special treatment in the form of plastic coating. For important steel wire ropes, appropriate lubricants are filled inside the rope to reduce friction. Domestic steel wire ropes are generally divided into three types according to the rope core material: organic (hemp core and cotton core), asbestos core or metal core, and there is usually no filler or lubricant inside the rope. Steel wire ropes can be divided into parallel winding ropes and interwinding ropes according to the mutual directions of the wire ropes and the strands, and according to the twisting direction of the strands, they can be divided into left and right twists in the same direction and left and right alternate twists; imported steel wire ropes Generally, the cross-wound rope is used as the standard rope. Correspondingly, the direction of rotation of the strands is also specified, that is, with the longitudinal axis of the strands as the benchmark, the direction of the helix of the outer wires constituting the strands is the direction of rotation of each strand. When a single wire rope is used, there is a phenomenon that the wire rope rotates in the opposite direction. When used in a sliding group, the twisting of the lifting wire rope will be caused by the rotation of the wire rope, commonly known as twisting.

　　Compared with ordinary wire ropes, non-rotating wire ropes have begun to be widely used. The so-called non-rotating wire rope is based on the principle that the torsional moment of the rope and the strands are opposite in direction and equal in magnitude: the imported non-rotating wire rope is different. When the force is applied, the torque generated by the rope core is equal to and opposite to the torque generated by the outer strands. The strands of the steel wire rope can also be made into compact strands by post-processing methods such as rolling or die extrusion, and the diameter of the strands after treatment will be reduced, and the surface finish will be high. Therefore, the wire rope with tight strands can use thicker steel wires. Under the same diameter, the filling coefficient of the wire rope with tight strands is higher, and the breaking force is greatly improved. When multi-layer winding is performed on the reel, the outer strands of the common-strand wire rope are severely squeezed between layers, and the surface of the wire rope wears quickly. The tight-strand wire rope has higher anti-wear ability and anti-extrusion ability.

　　Whether the selection of the wire rope is correct or not directly affects the service life of the rope and causes structural deformation, fracture and unexpected failure of the rope. Therefore, the recommended selection principles are as follows:

　　1. When lifting an unguided heavy object once or when lifting multiple unguided heavy objects at a large height, use a non-rotating wire rope;

　　2. When lifting a guided weight once or at a smaller height Ordinary steel wire ropes can be used when there is a guided weight lifting (such as driving) or when the left-handed and right-handed ropes are used in pairs.

　　The determination of the rotation direction of the wire rope should follow: the reel with the right-handed rope groove is recommended to use the left-handed wire rope; on the contrary, the reel of the left-handed rope groove should use the right-handed wire rope. For single-layer winding non-rotating wire ropes, the above principles must be strictly followed, otherwise the wire rope structure will be easily deformed; for multi-layer winding, the rotation direction of the rope is determined by the direction of the rope groove of the reel, so as to lay well for the next layer Base. The friction between the multi-layered reels and the squeezing force of the wire ropes are relatively large, which is easy to cause rope disorder. Therefore, wire ropes with a diameter slightly smaller than the groove pitch and groove diameter should be selected to increase the number of wire ropes and reels. The contact area between adjacent wire ropes reduces the friction between adjacent wire ropes, thereby improving the life of the wire ropes.

　　Practice has proved that the diameter of the wire rope is 1% smaller than the pitch of the rope groove, which helps to arrange the rope tightly and effectively eliminates the phenomenon of rope climbing and rope disorder. Under the same diameter, the more the outer strands of the steel wire rope are, the thinner the single steel wire is. This kind of steel wire rope has good flexibility and can well overcome the reverse bending force when the wire rope enters and exits the reel for many times. easy. Thicker outer strands, with thicker wires, are more resistant to wear, mechanical damage, corrosion and crushing forces. Therefore, only a good combination of the two advantages can be a real high-quality wire rope with high performance. In addition, in the selection process of steel wire rope, it should be noted that its small diameter and small breaking force should meet the requirements of ISO4308 standard.