METHOD FOR MAKING AND BREAKING THREADED CONNECTIONS OF PIPES AND DEVICE FOR EFFECTING THE SAME Russian patent published in 1997 - IPC

FIELD: mechanical engineering; may be used in drilling technology for making up and breaking out drill and casing pipes. SUBSTANCE: immovable pipe is held and pipe to be made up or broken out is rotated simultaneously from the same drive by imparting to them torques of the same value but of opposite directions. Pipe gripping mechanisms in both the wrenches are mounted in gear wheels engaged with gears of the common drive consisting of a high-speed reduction gear and a differential unit. The differential unit has a body and a carrier and is accommodated in the housings of both the wrenches. The body of the differential unit with outer and inner toothed rims is positioned in the housing of the drive wrench and the shaft of the carrier together with engaged driven gear is located in the housing of the holding wrench. The body of the differential unit is installed in radial bearings in holes of the drive wrench housing and retained by covers. The carrier of the differential unit is mounted in rolling bearings in the inner recess of the unit body. Passed through the same recess is a vertical shaft engaged in its bottom portion with the driven gear of the high-speed reduction gear and in its upper portion it is engaged with satellite gears of the differential unit carrier. EFFECT: enhanced efficiency and reliability. 3 cl