DRILL BIT BEARING STRUCTURE Russian patent published in 2009 - IPC E21B10/22 

FIELD: mining.

SUBSTANCE: present invention pertains to a rock breaking tool, and particularly to drill bit bearing structures. The device has a support bracket with a centre shaft, with oil ducts, and a roller bit, fixed on the centre shaft by friction bearings and an articulated roller bearing. The bearing structure of the roller bit, making up the friction bearing, has longitudinal grooves. The cross section of the grooves is tapered and the grooves are joined together by channels. The channels are made on the inner surface of projections, formed between the tapered grooves and projections on the inner surface with varying cross section, increasing in the direction of rotation of the roller bit. The bearing structure has a bushing, rigidly joined to the roller bit and located on the base of central shaft. On the inner surface of the bushing, there is a bore under a sealing element.

EFFECT: reduced impact load on the articulated bearing and its longer life span, consequently, and the bearing structure as a whole.

3 cl, 3 dwg