METHOD FOR RESTORING WORN CONE BITS Russian patent published in 2023 - IPC E21B10/00 

FIELD: mining industry.

SUBSTANCE: invention relates to the mining industry, and in particular to methods for the restoration and recycling of used drill bits. Method for restoration of worn cone bits includes selective processing and rejection of failed cone bits, washing, cutting into sections with elements of a share, cutter, assembly of serviceable sections, welding of sections with electrodes with continuous cooling of the cone bit, filling cavities of bearing supports with lubricant. Cutting into sections is carried out at the base of the paws of the cone bit perpendicular to its axis. After cutting the paws, the bearings are disassembled. Before assembling the sections, the bearing races and the sealing protrusion of the trunnion of each operable paw are ground down over the entire width of the raceway until repair diameters are formed, on which the bearing cages are installed with an interference fit, with the preliminary installation of the sealing washer. After installing the sealing washer on the inner race of the peripheral and end bearing, the rolling elements are installed and the cutter is put on, after which the rolling elements of the lock bearing are installed. Upon completion of the assembly of bearing supports with cones, the stage of assembling the cone bit follows, while pins are installed in the body of the cone bit, and holes corresponding to the pins are drilled in the paws of the cone bit. After that, the paws are installed on the calibration plate, the cone bit body is put on from above so that the pins installed in it enter the reciprocal holes of the paws, the difference in height of the paws and the non-parallelism of the end of the nipple end of the cone bit body to the calibration surface are eliminated by placing metal plates in the gaps formed between the cone bit body and paws. Upon completion of the elimination of the difference in height and non-parallelism of the end of the nipple of the cone bit body, the paws are welded to the cone bit body. After assembling the restored sections, hard-alloy electrodes are deposited on the outer surfaces of the paws and sealing washers until the geometric parameters of the paws are restored. Before filling the cavity of the bearing supports with lubricant, the restored bit is subjected to cryogenic treatment for 30-40 minutes.

EFFECT: ensuring the restoration of the cone bit with the exclusion of complex technological operations during assembly, with a complete restoration of the resource of the bearing supports of the cone and the sealing protrusions of the paws.

1 cl, 2 dwg