Floating Plug Anti-Leak

Abstract

A roller cone drill bit includes a pressure equalization bore defined within the roller cone drill bit that includes a lubricant chamber portion and an open portion. The drill bit also includes a lubricant passage defined within the drill bit and fluidically coupled to a first end of the lubricant chamber portion. Additionally, the roller cone drill bit includes a floating plug positioned within the pressure equalization bore between the lubricant chamber portion and the open portion. The floating plug is slidable along the pressure equalization bore and configured to seal the lubricant chamber portion from the open portion. Moreover, the roller cone drill bit includes a stop positioned at least partially within the pressure equalization bore or the lubricant passage to restrain the floating plug from sliding into the lubricant passage through the first end of the lubricant chamber portion.

What is claimed is: 
     
         1 . A roller cone drill bit comprising:
 a pressure equalization bore defined within the roller cone drill bit that includes a lubricant chamber portion and an open portion;   a lubricant passage defined within the drill bit and fluidically coupled to a first end of the lubricant chamber portion;   a floating plug positioned within the pressure equalization bore between the lubricant chamber portion and the open portion, wherein the floating plug is slidable along the pressure equalization bore and seals the lubricant chamber portion from the open portion; and   a stop positioned at least partially within the pressure equalization bore or the lubricant passage, wherein the stop restrains the floating plug from sliding into the lubricant passage through the first end of the lubricant chamber portion.   
     
     
         2 . The drill bit of  claim 1 , further comprising a bypass line that is connected to the pressure equalization bore at one end and the lubricant passage at an opposing end of the bypass line. 
     
     
         3 . The drill bit of  claim 1 , wherein the stop is a ledge machined into the pressure equalization bore. 
     
     
         4 . The drill bit of  claim 1 , wherein the stop is a solid body. 
     
     
         5 . The drill bit of  claim 4 , wherein the stop further includes a cup to receive the floating plug. 
     
     
         6 . The drill bit of  claim 4 , wherein the stop is chamfered, flat, rounded, convex, concave, or any combination thereof. 
     
     
         7 . The drill bit of  claim 1 , wherein the stop further includes an annular body having a stop bore extending axially through the stop. 
     
     
         8 . The drill bit of  claim 7 , wherein the stop further includes a pass-through bore. 
     
     
         9 . The drill bit of  claim 8 , wherein the stop is press-fit into the lubricant chamber portion. 
     
     
         10 . The drill bit of  claim 1 , wherein the stop is machined into the lubricant chamber portion. 
     
     
         11 . The drill bit of  claim 1 , wherein the stop further includes a slotted body. 
     
     
         12 . The drill bit of  claim 1 , wherein at least a part of the lubricant chamber portion has a diameter that is smaller than the floating plug. 
     
     
         13 . A method for forming a lubricant reservoir comprising:
 manufacturing a drill bit with a pressure equalization bore fluidically coupled to a lubricant passage and the lubricant passage fluidically coupled to one or more bearings;   positioning a stop at least partially within the lubricant passage or the pressure equalization bore of the drill bit, wherein the lubricant passage is fluidically coupled to a first end of a lubricant chamber portion of the pressure equalization bore;   positioning a floating plug within the pressure equalization bore between the lubricant chamber portion and an open portion of the pressure equalization bore, and wherein the floating plug is slidable along the pressure equalization bore and seals the lubricant chamber portion from the open portion; and   filling the lubricant reservoir with a lubricant, the lubricant reservoir extending from the floating plug in the lubricant chamber portion of the pressure equalization bore, through the lubricant passage, and to the one or more bearings.   
     
     
         14 . The method of  claim 13 , further comprising boring out the drill bit to form the pressure equalization bore. 
     
     
         15 . The method of  claim 13 , further comprising casting the drill bit to form the pressure equalization bore and the lubricant passage. 
     
     
         16 . The method of  claim 13 , wherein the pressure equalization bore includes a bypass line that is connected to the pressure equalization bore at one end and to the lubricant passage at an opposing end of the bypass line. 
     
     
         17 . The method of  claim 13 , wherein the stop includes a slotted body. 
     
     
         18 . The method of  claim 13 , wherein the stop is a ledge machined into the pressure equalization bore. 
     
     
         19 . The method of  claim 13 , wherein the stop is a solid body. 
     
     
         20 . The method of  claim 13 , wherein the stop is chamfered, flat, rounded, convex, concave, or any combination thereof.