METHOD FOR REINFORCING PIVOT SHAFTS OF DRILLING ROLLING CUTTER BIT LEGS Russian patent published in 2006 - IPC E21B10/36 F16C33/12 F16C33/02 C23C4/00 C23C24/00 C23C28/00 

FIELD: method for reinforcing pivot shafts of drilling rolling cutter bit legs, possible use in mechanical industry during manufacture of drilling equipment for building wells by deep and ultra-deep drilling, and also for drilling explosive wells with air blasting of bottomhole.

SUBSTANCE: prior to cementation, welding deposition of sliding bearing tracks is performed using hard alloy, and onto surfaces of leg pivot shafts not subjected to cementation, anti-cementation cover is applied. After cementation, heat hardening and low tempering, polishing and cleaning of sliding bearing tracks is performed. Then, wear-resistant protective cover is applied onto them with hardness ranging from HRC 65 to HRA 74 by spraying at warming temperature of leg pivot shaft not exceeding softening temperature of cemented surfaces. Protective cover is applied, when maximum temperature of leg pivot shaft warming does not exceed 280°C. Wear-resistant protective cover is applied in one or several layers, until given rated thickness of 0,1÷0,5 millimeters is reached. At thickness of protective cover more than 0,2 millimeters unevenness of layer application may be corrected by micro-smoothing using diamond wheels.

EFFECT: substantially increased hardness on the surface of sliding bearings of leg pivot shafts and to appropriately increase their own wear resistance as well as that of drilling bits as a whole.

4 cl, 1 dwg