DRILLING BIT BEARING STRUCTURE Russian patent published in 2008 - IPC E21B10/22 

FIELD: rock-cutting tools, particularly drilling bit bearing structures.

SUBSTANCE: bearing structure comprises pin, cone cutter secured to pin by means of retaining drilling bit bearing. The retaining drilling bit bearing is made as collet bush having the first end inserted in annular groove of cone cutter and another end cooperating with collet support. One or both end parts of collet bush are made as bearing retainers. Central part of collet bush is made as friction bearing having longitudinal grooves in inner and outer surfaces thereof. The grooves are arranged in staggered order and filled with lubricant or/and wear-resistant material. Pin support to receive collet bush is made as ball retaining drilling bit bearing, spring ring arranged in annular pin groove or is defined by L-shaped end section arranged in annular pin groove.

EFFECT: increased contact surface between cone cutter and pin to decrease contact stress in-between and extended service life of bearing structure.

2 cl, 5 dwg