Roller drill bit having radial-thrust pilot bushing incorporating anti-galling material

Abstract From the Canadian patent

A rolling cutter earth drilling bit in which integral one-piece pilot bushings provide both radial and thrust load sliding surfaces which incorporate an anti-galling material. A roller cone bit has three downwardly extending arm members which terminate in cylindrical spindles for the rolling cutters. Each spindle has a stepped configuration providing an enlarged journal section which is stepped down to provide an annular thrust shoulder and a reduced pilot pin which projects from the thrust shoulder. The rolling cutter mounted on the spindle has an enlarged rearward bearing recess which receives the journal section of the spindle and a reduced forward bearing recess whcih receives the …