DRILLING BIT BEARING FOR AIR DRILLING

drilling bits used, mainly, in air drilling. SUBSTANCE: drilling bit bearing has a journal, roller cutter installed on cone pin by means of radial bearings and plain thrust bearing including intermediate floating circular washer with radial channels made on its end face. Each end face of washer has eccentric circular groove separating it into external and internal contacting end faces, and radial grooves on these surfaces are displaced relative to one another over circumferences. In this case, width B of eccentric circular groove, washer width H and eccentrically E are interrelated as B= 0.10-0.15 H=0.9-0.95 E. Making circular groove concentric to washer axis and displacement of radial grooves on external and internal contacting surfaces makes it possible to increase wear resistance of plain thrust bearing due to improved lubricating conditions of bearing and intensified its cooling, and to increase service life of bearing. EFFECT: higher efficiency. 3 dwg