Linkage multi-jaw hydraulic power back-up wrench

Abstract

The invention relates to a linkage multi-jaw hydraulic power back-up wrench. Acting force of a hydraulic cylinder directly acts on a clamped string by the aid of a movement pair between a translation jaw assembly and a back-up wrench body of the linkage multi-jaw hydraulic power back-up wrench, at the moment, linear movement of a cylinder body or a piston rod of the hydraulic cylinder is converted into rotation of clamping arms by the aid of a fixed hinge form of two rotary pairs and a movable hinge form of two other rotary pairs, the rotary pairs are arranged among the hydraulic cylinder and rotary jaw assemblies, and the acting force outputted by the hydraulic cylinder acts on the clamped string, so that the purpose of clamping the clamped string in a three-point linkage manner is achieved. The linkage multi-jaw hydraulic power back-up wrench has the advantages of reasonable design, simple principle, compact structure, convenience in manufacture, good clamping stability and low quantity of easily damaged parts.

Description

technical field [0001] The invention relates to a hydraulic power tong, in particular to a hydraulic power back tong of a multi-tooth linkage clamping oil pipe hydraulic power tong, which belongs to the technical field of petroleum equipment manufacturing. Background technique [0002] In oilfield wellhead tubing, casing, and drill pipe threads making and breaking, in order to make the threaded connection of the above-mentioned pipe strings easy to disassemble and stable, a power tong for pipe is usually used. This power tong consists of Composed of main tongs and backup tongs, the main tongs play the role of clamping and rotating buckle, and the back tongs play the role of clamping and fixing the connecting pipe. The clamping form of the traditional power tongs for oilfield pipes is as follows: in the cavity contained by the main body of the back tong and the cover plate of the back tong head, there are four inner curved slope plates, the rollers are installed on the jaw pl...

AI Technical Summary

Problems solved by technology

However, although this structure can realize the clamping of any pipe string, its structure is relatively complicated, and there are many parts involved, especially the existence of gear meshing pairs, which not only requires higher machining accuracy, but also makes manufacturing more difficult. Large, and iron filings or other hard debris are easily caught in the gear meshing pair, which may easily cause the meshing pair to be stuck

Therefore, the back vise clamping device with the latter structure has high precision requirements, high manufacturing costs, and poor working stability.

The power of the above-mentioned structure is transmitted to the jaws to clamp the oil pipe by means of a gear train or other transmission components. The transmission is complicated, and there are many wearing parts, so the clamping is unreliable.

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