| 摘要 |
In a rotary drill bit assembly, comprising a drill bit body, at least one trunnion and a rotary cutter rotatably supported on the rotary cutter by bearing means including at least one inner roller bearing, the rollers of the inner roller bearings running in a deep radial bearing race groove in the trunnion and a deep radial bearing race groove formed in the bore of the rotary cutter and a filling opening extending generally axially in the trunnion between the inner bearing race grooves, characterized in that the outer bearing facing the drill bit body comprises a tapered roller bearing including a plurality of tapered rollers and wherein the filling opening for the rolling elements of the inner bearing is arranged radially inside the inner bearing race of the tapered rollers in the trunnion. |
