DRILLING BIT WITH AIR-TIGHT BEARINGS FOR DRILLING WELLS WITH WELL BOTTOM FLUSHING WITH AIR Russian patent published in 2006 - IPC E21B10/18 

FIELD: drilling equipment, particularly drilling bits.

SUBSTANCE: cooling is performed by providing direct air flows circulation in gaps between drilling bit leg, axle and rolling members along with air flows discharge through central channel made in the axle. Air flow parts are supplied into unloaded roller bearing zones and in grooves of thrust journal and are directed through one or several orifices of unloaded major race, which are communicated with channels extending through axle and in leg body. The air flow parts bypass seal and orifice for locking finger receiving. Outlet orifices to feed air flows from bearing assembly cavity to hole annuity are created in rounded leg back surfaces so that cooling air jets are directed in gap between leg back and well wall or the outlet orifices are formed in side leg surfaces so that the jets are directed into hole annuity by-passing well wall to create injection effect during well bottom cleaning of cut rock.

EFFECT: provision of direct cooling agent contact with bearing assembly races and rolling members.

4 cl, 8 dwg