Scientific choice of wire rope structure for rotary drilling rig

1.1 Features
The main function of the wire rope for the rotary drilling rig is to lift the kelly bars and drilling tools, and complete the drilling and reaming projects in the pile foundation project.
(1) The wire rope for rotary drilling rig is subjected to torsional load during operation.
(2) Since there are no moving pulleys installed in rotary drilling rigs at home and abroad, the single-rope tension of the steel wire rope is relatively large.
(3) The state of the multi-layer winding of the steel wire rope used in the rotary drilling rig has not been completely eradicated. The problems of skipping, messing and biting of the drum have always been the key factors restricting the service life of the steel wire rope.
(4) The working environment of the steel wire rope used in the rotary drilling rig is harsh, and it often works in corrosive mud. The technical requirements for the selection of the grease applied to the steel wire rope are high. When using it, the state of the steel wire rope should be checked frequently and the grease should be replenished in time.
(5) In the process of rotary excavation, when lifting the drill pipe and drill tool, the force acting on the wire rope is an alternating load.
(6) The diameter of the main and auxiliary winding pulleys of rotary drilling rigs at home and abroad is generally small, so the ratio of the diameter to the diameter of the wire rope is small, which will reduce the bending fatigue resistance of the wire rope and affect the performance and service life of the wire rope.

(7) The service life of the wire rope mainly depends on the size of the rope groove and the correct selection of the ratio of the diameter D of the wire rope and the diameter d of the drum (or the bottom of the pulley). Rotary drilling rigs are usually selected: D/d≥20, D/do≥250, where d. It is the outermost wire diameter of the wire rope.
(8) When the rotary drilling rig is working, always use the first layer of lifting force of the steel wire rope, and the lifting force must be stable.