1. Rope structure
Multilayer wire rope is twisted into strands, then rope core as the center, by a number of strands twisted into a spiral around the rope.
(A) wires. Play a role in load bearing rope, the performance is mainly determined by the wire. Carbon steel or alloy steel wire is cold-drawn or cold-formed by a circular (or shaped) wire, high strength and toughness, and according to different environmental conditions for surface treatment of steel.
(2) the cord. It is used to increase flexibility and toughness steel wire, copper wire lubrication, reduce friction and increase the service life. Organic fiber cord used (such as hemp, cotton), synthetic fibers, asbestos core (high temperature) or a soft metal and other materials.
2. Types of ropes
Crane double twisting multi-strand rope round rope.
(A) by wire contact state classification, can be divided into point contact, line contact and surface contact wire.
① point contact wire rope (also known as the common type) is the use of equal diameter wire twisting. As the layers ranging from wire twist, the layers formed between the wire and the wire point contact. The contact wire under load stress is high, easy to wear, broken, lower life, the advantage of manufacturing process is simple and inexpensive. Point of contact wire bundle lifting operations often as slings, crane working bodies have adopted.
② line contact wire is a wire with a diameter ranging from twisting. The inner and outer layer filaments properly configured so that the different layers are formed between the wire and the wire-line contact, so the contact wire under load stress is reduced. Rope line contact high capacity, flexible, and life expectancy is higher. Commonly used rope line contact with Silvio type (also known as the outer coarse type), Wallin swallow-type (also known as the thickness of the type), filled (also known as intensive) and so on. (Crane design specifications "recommendation, the crane's working bodies in line contact preferred rope.
③ surface contact wire (also known as sealed). Usually round steel wire strand core as the outermost layer or layers using the special section of the wire between the layers is in surface contact with the extrusion around the system. Which is characterized by smooth surface, good flexibility, high strength. Corrosion resistance, but the manufacturing process is complex, expensive, rarely used cranes, used as cable cranes and aerial tramway carrying cable.
(2) Classification by rope twist. According rope wire twisted into shares by the direction of the strands twisted into a rope direction is consistent, can be divided into:
① interactive twist rope (also known as cross-roping). Its wire twisted into strands and strands twisted into a rope in the opposite direction. As stocks and rope grab to the contrary, it is not easy to twist and loose with the widespread use of cranes.
② the same direction twist rope (also known as cis-roping). Its wire twisted into strands and strands twisted into a rope in the same direction, are more flexible and interactive twist rope life is better, but because of its easy to reverse, loose, generally only used for traction rope.
③ Do not twist rope. This rope was designed so that stocks with rope twisting moment is equal and opposite to overcome in use reverse phenomenon, often in a large crane lifting height to use, and more and more attention.
