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

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

SUBSTANCE: roller bit comprises body with inclined axles adapted to support cutters. The cutters are installed with the use of retaining bearing and end bearing inserted in conical axle bore. Each end bearing has conical surfaces from cutter side and is arranged in conical bore made in inner end surface of the cutter. Conical bore of the cutter and end bearing cone mate each other. End friction bearing may be installed in conical bores of the axle and the cutter and may rotate in respect thereto or fixedly secured is one bore. End friction bearing is made of solid lubricant or wear-resistant material.

EFFECT: increased advance speed.

5 cl, 2 dwg