Patent ID: 7861805
Filing Date: 2011-01-04
Classification: E21B,F16C

Abstract:
1. An earth boring bit, comprising: a bit body having at least one depending leg; a bearing pin extending from the leg and having an axis and a journal surface that is rotationally asymmetric about the axis from an outer end of the journal surface at a junction with a gland area engaged by a seal, to an inner end at a junction with a race for balls; and a cone having a cavity slidingly mounted to the journal surface of the bearing pin and being rotatable relative to the bearing pin; and the journal surface comprises a main journal bearing surface on a proximal end of the bearing pin, and a pilot pin radial bearing surface on a distal end of the bearing pin, and both the main journal bearing surface and the pilot pin radial bearing surface are rotationally asymmetric about the axis.