GEAR TO CLEAN INTERNAL SURFACE OF PIPES Russian patent published in 2004 - IPC

FIELD: oil and gas industry, cleaning of operational string and tubing string of well. SUBSTANCE: gear includes hollow bodies of stages. Each stage comprises front part with peripheral conduits and rear part. Both parts are joined by means of threaded connection fitted with spacing- centering bushing. Enclosure is linked to front part of body of first stage. Rod with open longitudinal conduits is installed inside hollow bodies. Bushing forms peripheral conduits at outlet of unitary, elastic, step-shaped scrapers. Longitudinal conduits are arranged in correspondence with peripheral conduits of hollow bodies of stages. Substitute with hole to accommodate rod intercouples hollow bodies of stages and comes in the form of threaded pairs with threaded connection of same thread pitch. One threaded pair has threaded connection of opposite direction and is stopped by lockpins arranged over circumference, girdled by clamp and is tightened by check nut that is locked. There is section of convergence of conduits of hollow bodies of stages and rods which is bent. Rod is mounted for axial movement. Unitary, elastic, bar- shaped scrapers attached to rod with rear ends are installed in conduits of bodies of stages. Pushers are positioned in each stage between shock-absorber and unitary, elastic scrapers in section of their bending. Gear has compensator of wear-out of unitary, elastic , bar-shaped scrapers mounted foe interaction with rod. Unitary, elastic, bar-shaped scrapers are distributed in stages in turn, over circumference of rod. EFFECT: enhanced cleaning efficiency and productivity. 6 dwg