DEMOUNTABLE ROCK DRILL WITH CONE ROLLERS ON BALL BEARINGS WITH CAGES Russian patent published in 2008 - IPC E21B10/08 

FIELD: petroleum industry.

SUBSTANCE: invention relates to drill bits namely to the design of a rock drill intended for drilling wells of various designation. The technical result is reduction of labour consumption for fabrication, increase of efficiency of the drill support and increase of drilling capacity in construction of deep wells. The rock drill consists of three independent parts: the connector, the case and the pre-assembled unit. The connector has conical, tool-joint and metric thread for connection with the drilling column and the rock drill and flats for the wrench. The rock drill case has threaded holes for connection with pre-assembled units. The pre-assembled unit contains a pivot journal, a fixing mechanism in the shape of a split-type flange with fixing screws arranged beyond the working zone of the pivot journal and fixed on the end surface of the flange of the cone rollers and anti-friction liners, the flange being accommodated in the cavity of the cone roller of the thrust bearing. The rock drill is made in the shape of a solid ring with three holes for cleaning the well face and fitted with three short lugs with threaded holes for connection with pre-assembled units. Two standard radial ball bearings with cages are mounted in the cavity of the pivot journal; the mounting dimensions for the said bearings on the pivot journal are selected from the ratio where d is the cross-sectional diameter of the pivot journal in the place of mounting the bearing. The thrust bearing is made in the shape of a standard radial thrust bearing and the size of the cone roller cavity provides equal strength of walls in all sections.

EFFECT: increase of efficiency of the rock drill support and increase of production capacity of drilling deep wells.

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