DRILLING TOOLS Russian patent published in 2018 - IPC E21B10/22 E21B10/28 

FIELD: mining.

SUBSTANCE: invention can be used in mining for direct drilling of wells with stepped bottom hole form, or for expansion of previously drilled well. Drilling tool consists of body equipped with central air duct with attached legs to trunnions, each of which is equipped with rolling cutter with rolling bearings, reservoirs with lubricant located in legs and having lubricating channels, outlets leaving central air passage of housing, outlet openings of which are connected to lubricating channels having outlet in bearing cavity and further into annulus of borehole through seals between cutters and trunnions. Cutters have through axial hole, trunnions on side opposite to paw are installed into holes of body with exit of their extensions into central air-passage channel. Leads are located in pins, their inlet holes on sprocket extensions are directed counter to the air flow of central air-channel. Part of lubricating channels, located in trunnions, is made in form of throttle. Leading rock-cutting elements are attached to hull or it has device for connecting leading drilling tool of smaller diameter and / or drill rod.

EFFECT: technical result is to reduce oil consumption with increasing amount of air used to cool cones of cutters.

2 cl, 2 dwg