Dual-seal drill bit with fluid cleaning capability.

摘要

A drill bit for use in an earthen annulus that contains loose particles is connected to a fluid supply source and includes a bit body having at least one journal segment an d at least one fluid conduit in fluid communication with the fluid supply source. A roller cone i s rotatably mounted upon the journal segment and forms at least one bearing cavity therebetween. Annular primary and secondary seals are disposed between the roller cone and the bit body an d between the bearing cavity and the earthen annulus. An air groove is provided around at least a portion of the cone or leg between the primary seal and the earthen annulus. The groove circumscrib es less than the entire circumference of the groove or leg, and in preferred embodiments includes an exit port and/or a diversion plug. Both the exit port and the diversion plug help prevent the groove from becoming plugged with debris.