Bearings for roller cutter assembly

摘要

A roller cutter assembly for a roller reamer which can be attached to a drill string is formed of a cylindrical body having an integral tapered bearing pin at each end. A journal bearing block for each bearing pin can be secured to the roller reamer by welding so as to hold the cutter rotatably on the reamer. The bearing block has a diameter slightly larger than that of the bearing pin. The angle of taper of the bearing pins and bearing surfaces is greater than the arc tangent of the coefficient of static friction between the coacting bearing surfaces such that the bearing pins do not self-lock in the bearing blocks.