HYDRAULIC DRILL Russian patent published in 1997 - IPC

FIELD: mining industry. SUBSTANCE: this relates to bottom-hole drilling motors. Drill has body, inner and outer shafts installed in body at circular clearance and kinematically interconnected for possible rotation in opposite directions. Also located inside body are inner shaft drive and drill bit. Inner shaft drive is embodied in the form of locking rollers freely rotating on their axles and having cylindrical recesses. Locking rollers are installed in slots of body. Combined in inner shaft drive are also rollers installed in slots of inner and outer shafts with formation in circular clearance between shafts and body of chambers for delivery of sludgy drilling fluid into drive and for branching this fluid from bottom-hole zone. Body is provided with passages for fluid to deliver it into chambers and branching it from chambers. Recesses in locking rollers are made with radius which is equal to radius of rollers of outer and inner shafts. Hydraulic drill is provided with additional bits and additional shafts installed on main and additional bits. Shafts of bits are kinematically linked with inner and outer shafts by transmission with different transmission ratio. EFFECT: high efficiency. 3 cl, 4 dwg