POWER DRIVER Russian patent published in 2004 - IPC

FIELD: deep drilling of wells, namely screwing-unscrewing well pipes, mainly at performing descending-lifting operations during drilling process. SUBSTANCE: power driver includes housing, rotary pinion with lateral port, pipe clamping mechanism with jaw holder supporting jaws; drive unit joined with rotary pinion between two intermediate gear wheels; supporting rollers engaging with outer surface of rotary pinion; rollers for guiding jaw holder mounted in rotary pinion or in jaw holder. Rotary pinion has contour followers on inner surface. Each jaw of driver includes body and insert jointly connected one with another, arranged at one side relative to rotation axis in jaw holder and having in their ends at side turned to clamped pipe toothed nibs and at side turned to contour follower of rotary pinion - supporting area. Jaw includes self-aligning roller having ridges for moving along contour follower of rotary pinion and one or more journal necks for simultaneously engaging with supporting areas of body and of jaw insert. EFFECT: improved simplified design, rather small cost, minimum hazard of damaging pipe at clamping it due to uniform distribution of load in zones of engagement of pipe-clamping devices with pipe. 2 cl, 11 dwg