External, divorced PDC bearing assemblies for hybrid drill bits

摘要

A hybrid-type earth boring drill bit is described having fixed cutting blades and rolling cones with cutting elements, wherein the rolling cones are associated with a spindle assembly that may be optionally divorced from the head pin assembly, and which includes bearing members that further include a plurality of polycrystalline diamond elements.

主权项

1. A hybrid rotary drill bit comprising:
a bit body; at least one fixed blade extending in an axial direction downwardly from the bit body and having at least one fixed cutting element disposed thereon; at least one rolling cutter leg extending in an axial direction downwardly from the bit body; a rolling cutter rotatably coupled to the at least one rolling cutter leg and having an interior recess formed within the rolling cutter, the recess comprising a circumferential groove; at least one cutting element disposed on the rolling cutter; and a divorced rolling cutter bearing assembly configured to removably engage a portion of the at least one rolling cutter leg and comprising:
a) a first bearing sleeve assembly configured to engage the recess; orb) first and second cylindrically-shaped bearing sleeve assemblies each configured to engage different portions of the recess on either side of the groove; orc) a planar thrust bearing assembly configured to engage a portion of the recess; the divorced rolling cutter bearing assembly comprising at least one bearing element coupled to an external portion of the divorced rolling cutter bearing assembly and configured to facilitate rotation between the rolling cutter and the at least one roller cutter leg.