DRILL BIT BEARING STRUCTURE Russian patent published in 2007 - IPC E21B10/22 

FIELD: rock-cutting tools, particularly roller bits characterized by bearing or lubricating details.

SUBSTANCE: bearing structure comprises hollow pin, roller cutter secured to pin by means of ball bearing member. The bearing member is provided with separator made as radial orifices distributed along pin perimeter and communicated with pin interior. Arranged between orifices are partitions. Cylindrical locking member may be installed in pin interior and may cooperate with bearing member balls. The bearing structure has additional supporting units arranged in race-track between retaining bearing member balls so that the support units may cooperate with the balls, separator and inner surface of ball race-track. Part of each additional supporting unit from leading part thereof is made of solid lubrication material. Additional supporting unit end has depression mating in shape with retaining bearing member ball cooperating with it. Each additional supporting member is provided with elastic member installed at end opposite to part made of solid lubrication material. Summary member length in initial position is greater than distance between balls surrounding them.

EFFECT: increased resistance due to increased contact surface of bearing members and proportionately decreased specific loads applied thereto and, as a result, increased drill bit efficiency and improved performance characteristics of drilling operations.

3 dwg