Earth-boring tools including bearing element assemblies, and related methods

Abstract

An earth-boring tool includes a body comprising a pocket in a leading end thereof for accepting at least a portion of a bearing element assembly. A bearing element assembly may be disposed within the pocket, and the bearing element assembly may include a retaining element at least partially disposed in a groove in a sidewall of the pocket and a bearing element. The bearing element may include a distal end having a bearing surface, a proximal end, and a side surface between the distal end and the proximal end, the side surface comprising a feature configured to abut the retaining element, wherein mechanical interference between the feature and the retaining element axially retains the bearing element within the pocket. Methods include disengaging a mechanical retention device retaining a bearing element within a pocket in a body of the earth-boring tool, and removing the bearing element from the pocket.

What is claimed is: 
     
         1 . An earth-boring tool, comprising:
 a body comprising a pocket in a leading end thereof for accepting at least a portion of a bearing element assembly; and   a bearing element assembly disposed within the pocket, the bearing element assembly comprising:
 a retaining element at least partially disposed in a groove in a sidewall of the pocket; and 
 a bearing element comprising:
 a distal end having a bearing surface; 
 a proximal end; and 
 a side surface between the distal end and the proximal end, the side surface comprising a feature configured to abut the retaining element, wherein mechanical interference between the feature and the retaining element axially retains the bearing element within the pocket. 
 
   
     
     
         2 . The earth-boring tool of  claim 1 , further comprising at least one removal access hole extending through an exterior surface of the body and intersecting the pocket, wherein the at least one removal access hole is configured to receive a removal tool. 
     
     
         3 . The earth-boring tool of  claim 2 , wherein the at least one removal access hole is defined by a channel in the sidewall of the pocket and extending in a direction substantially parallel to a central axis of the pocket. 
     
     
         4 . The earth-boring tool of  claim 3 , wherein the at least one removal access hole comprises a plurality of channels spaced equidistantly around the sidewall of the pocket. 
     
     
         5 . The earth-boring tool of  claim 3 , wherein the side surface of the bearing element comprises a notch adjacent the channel. 
     
     
         6 . The earth-boring tool of  claim 2 , wherein the at least one removal access hole comprises a bore extending through an exterior surface of the body and intersecting the pocket. 
     
     
         7 . The earth-boring tool of  claim 6 , wherein the bore intersects the pocket adjacent a proximal surface of the bearing element. 
     
     
         8 . The earth-boring tool of  claim 1 , wherein the feature comprises a substantially annular flange extending laterally from the side surface of the bearing element. 
     
     
         9 . The earth-boring tool of  claim 8 , wherein the sidewall of the pocket comprises a first portion having a first diameter extending into the body a first depth along a central axis of the pocket and a second portion having a second diameter extending into the body a second depth along the central axis of the pocket, wherein the first diameter is greater than the second diameter and the second depth is greater than the first depth. 
     
     
         10 . The earth-boring tool of  claim 1 , wherein the feature comprises a portion of the side surface of the bearing element within a substantially annular recess. 
     
     
         11 . The earth-boring tool of  claim 1 , wherein the earth-boring tool is a fixed-cutter rotary drill bit. 
     
     
         12 . An earth-boring tool, comprising:
 a body comprising a threaded receptacle in a leading end thereof for accepting at least a portion of a bearing element assembly; and   a bearing element assembly disposed within the threaded receptacle, the bearing element assembly comprising:
 a holder with a receptacle at a distal end thereof for receiving a bearing element and a threaded outer surface at a proximal end thereof for engagement with the threaded receptacle in the body of the earth-boring tool; and 
 at least one feature proximate the distal end of the holder configured to interface with a tool adapted to apply torque to the holder. 
   
     
     
         13 . The earth-boring tool of  claim 12 , wherein the threaded receptacle comprises a sleeve with an at least partially threaded inner diameter and a generally smooth outer diameter, and the sleeve is affixed within a pocket of the body. 
     
     
         14 . The earth-boring tool of  claim 13 , further comprising a slot extending from an exterior surface of the body to a portion of an outer surface of the sleeve. 
     
     
         15 . The earth-boring tool of  claim 12 , wherein the threaded outer surface of the holder is configured substantially identically to an outer surface of a nozzle insert for insertion in a fluid outlet port in the body of the earth-boring tool. 
     
     
         16 . The earth-boring tool of  claim 15 , wherein the bearing element assembly comprises an internal fluid passageway in communication with a fluid port in the body of the earth-boring tool and in communication with one or more fluid outlets in a side surface of the bearing element. 
     
     
         17 . A method of replacing a bearing element of an earth-boring tool, comprising:
 disengaging a mechanical retention device retaining a first bearing element within a pocket in a body of the earth-boring tool;   removing the first bearing element from the pocket;   placing a second bearing element in the pocket, wherein the second bearing element comprises at least one of a shape of a bearing surface and an exposure of a bearing surface different from the first bearing element; and   engaging the mechanical retention device to retain the second bearing element within the pocket.   
     
     
         18 . The method of  claim 17 , wherein disengaging the mechanical retention device comprises rotating the bearing element relative to the pocket to disengage threads on an outer surface of the bearing element from threads in a sidewall of the pocket. 
     
     
         19 . The method of  claim 17 , wherein disengaging the mechanical retention device comprises removing a retaining element from a groove in a sidewall of the pocket. 
     
     
         20 . The method of  claim 17 , wherein disengaging the mechanical retention device comprises applying a force to a surface of the bearing element with a tool inserted in a removal access hole extending through an exterior surface of the body and intersecting the pocket.