The lifter, also known as "rotary union" and "power breaker", is a very important part of the rotary drilling rig, which is used to lift drill pipes and drilling tools. The upper end is connected with the main hoisting wire rope of the drilling rig, and the lower end is connected with the drilling rig. The rod connection, with the retracting and unwinding of the main hoisting wire rope, drives the lifting and lowering of the rotary drill rod and the drill bit, and when the power head is rotating, the drill bit bears the torsion force of the drill rod when drilling and throwing soil. Through its own rotation, the torsion transmission of the steel wire rope due to the rotation of the drill pipe is removed, and the steel wire rope is prevented from kinking, winding, breaking, etc. due to torsion, which may cause major accidents. Therefore, the lifter must have sufficient tensile strength and flexible rotation ability under high tension.