Ball cage type cardan shaft for screw drilling tool

Abstract

The invention relates to a ball-cage-type universal shaft of a screw drill. The ball-cage-type universal shaft of the screw drill is used for linkage and power transmission of the screw drill. Outer sleeve connectors at the two ends of the screw drill are connected with a transmission shaft and a rotor of the screw drill respectively. Each outer sleeve connector is connected with a middle shaft through a steel ball inside a retaining frame. The end portion of each outer sleeve connector is provided with a sealing cover, and the end portion of each sealing cover is provided with a clamping cover. A clamping ring and a safe pulling device are sequentially arranged between each sealing cover and the corresponding retaining frame. Shock-absorbing devices are arranged on the connection portions of the outer sleeve connectors and the middle shaft. The ball-cage-type universal shaft is good in shock-absorption and sealing performance and high in high-temperature resistance, high-pressure resistance and abrasion resistance, the service life is greatly prolonged, and the ball-cage-type universal shaft can normally work in the environment with high pressure of 7 atm or 0.7 MPa at a high temperature of 180 DEG C, can continuously safely run for more than 400 hours underground in a failure-free state, is strong in underground operation adaptation ability, convenient to install and adjust, quick, easy and convenient to disassemble and assemble and capable of effectively shortening maintenance and replacement time and improves drilling efficiency.

Description

Technical field [0001] The invention relates to the technical field of downhole power tools, in particular to a ball cage universal joint shaft suitable for screw drilling tools. Background technique [0002] As an important part of screw drilling tools, most of the cardan shafts originally used petal type universal joint shafts, flexible shaft type universal joint shafts and ball hinge type universal joint shafts. The petal type universal joint shafts have a simple structure but have a low life span. 100-200 hours; Flexible shaft universal joint shaft has a long service life, but it cannot be used for screw drilling tools with larger curvatures, and at the same time the price is higher; the current life of ball articulated universal joint shaft is more than 200-300 hours, but within After the parts are used for more than a certain period of time, the wear is more serious, and the existing sealing structure has poor sealing performance. The mud will enter the joints at both ends,...

AI Technical Summary

Problems solved by technology

[0002] As an important part of the screw drilling tool, most of the cardan shafts used to be petal-type cardan shafts, flexure-type cardan shafts and ball joint-type cardan shafts. The structure of the petal-type cardan shafts is simple but the life is relatively low 100-200 hours; the flexure-type cardan shaft has a high service life, but it cannot be used for screw drilling tools with a large curvature, and the price is relatively high; After the parts are used for a certain period of time, the wear is serious, and the sealing performance of the existing sealing structure is poor, and the mud will enter the joints at both ends, thereby accelerating its wear and causing damage to the rubber part; at the same time, the above cardan shafts have poor shock absorption and high temperature resistance , Poor high pressure, small swing angle, fast wear of parts, and the service life is far lower than other components, which greatly reduces the overall service life of the screw drilling tool, resulting in frequent replacement of cardan shafts during use, increased production costs, and poor drilling inefficiency

Images