PDC DRILL BIT WITH EXPANDING SPRING LOCK FOR ROTATING CUTTERS Russian patent published in 2022 - IPC E21B10/46 E21B10/573 

FIELD: drilling.

SUBSTANCE: invention relates to a tool for drilling petroleum and gas boreholes. PDC drill bit with rotating cutters includes a steel body with protruding blades, washing assemblies located in grooves between the blades, a threaded nipple part for attachment to the drill string, and holes on the surfaces of the blades with rotating diamond cutters placed therein. A joint annular cavity is made on the walls of the holes for the PDC cutters and on the walls of the hard-alloy substrates of the PDC cutters at the same distance from the bottom of the hole and from the end of the PDC cutter, said cavity being formed by a half-groove in the form of an annular cavity on the wall of the hole for the PDC cutter and a half-groove in the form of an annular cavity on the wall of the hard-alloy substrate of the PDC cutter. An expanding spring lock with a through longitudinal groove on the side wall thereof and an angular lead-in chamfer is installed in the joint cavity, configured for the outer surface of the expanding spring lock to be compressed by the wall of the hole during installation due to the width of the through longitudinal groove being reduced and to be subsequently restored due to spring release of the expanding spring lock inside the joint annular cavity after installation. The difference between the length of the maximum outer circumference of the expanding spring lock in the expanded state and the length of the minimum outer circumference of the expanding spring lock in the compressed state should be less than the width of the through longitudinal groove, and the cutting planes of the cutter plates should be inclined relative to the plane extending through the centre of the plate and the drill bit axis at an acute angle, configured for guaranteed formation of the moment of rotation of the cutters relative to the axes thereof and cutting of the rock at the bottom-hole consecutively using the entire length of the cutting edge.

EFFECT: increase in the durability of PDC cutters, headway per bit, and drilling rate, as well as simplification of the technology for manufacturing a drill bit with high reliability and productivity.

1 cl, 5 dwg