Rolling cutter

Abstract

A cutting element for a drill bit includes an outer support element and an inner rotatable cutting element, a portion of which is disposed in the outer support element, where the inner rotatable cutting element has a body with a non-planar cutting face.

What is claimed is: 
     
       1. A cutting element for a drill bit, comprising:
 an outer support element; and   an inner rotatable cutting element, a portion of which is disposed in the outer support element, the inner rotatable cutting element comprising:
 a body having a non-planar cutting face; 
 wherein the body comprises an ultra hard material body disposed on a substrate, the ultra hard material body forming the non-planar cutting face; and 
 wherein a radial bearing is formed between a portion of the ultra hard material body and the outer support element. 
   
     
     
       2. The cutting element of  claim 1 , wherein the ultra hard material body comprises diamond. 
     
     
       3. The cutting element of  claim 1 , wherein the outer support element covers a portion of the non-planar cutting face. 
     
     
       4. A cutting element for a drill bit, comprising:
 an outer support element;   an inner rotatable cutting element, a portion of which is disposed in the outer support element, the inner rotatable cutting element comprising:
 a non-planar cutting face; 
 a body comprising a shaft portion, the shaft portion having a diameter less than the diameter of the non-planar cutting face; and 
 an axial bearing formed between a portion of the outer support element and the inner rotatable cutting element. 
   
     
     
       5. The cutting element of  claim 4 , wherein the non-planar cutting face comprises a plurality of surface alterations formed thereon. 
     
     
       6. The cutting structure of  claim 5 , wherein the surface alterations have a depth ranging from 0.001 to 0.05 inches. 
     
     
       7. The cutting element of  claim 4 , wherein the non-planar cutting face is dome shaped, the dome shape extending across the diameter of the non-planar cutting face. 
     
     
       8. The cutting element of  claim 4 , wherein the non-planar cutting face has a convex shape. 
     
     
       9. The cutting element of  claim 4 , wherein the cutting element further comprises at least one retention mechanism disposed between the inner rotatable cutting element and the outer support element. 
     
     
       10. A drill bit, comprising:
 a bit body having a plurality of blades extending radially from the bit body and axially along a length of the bit body; and   at least one cutting element of  claim 4  mounted to at least one of the plurality of blades.   
     
     
       11. The cutting element of  claim 4 , wherein the non-planar cutting face is saddle shaped. 
     
     
       12. A cutting structure for a cutting tool, comprising:
 an outer support element having a bottom portion and a side portion; and   an inner rotatable cutting element, a portion of which is disposed in the outer support element;   wherein the outer support element further comprises an inner shaft portion extending from the bottom portion into the inner rotatable cutting element.   
     
     
       13. The cutting structure of  claim 12 , wherein the inner shaft portion is threadedly attached to the bottom portion. 
     
     
       14. The cutting structure of  claim 12 , wherein the inner shaft portion is integral with the bottom portion. 
     
     
       15. The cutting structure of  claim 12 , wherein an upper end of the inner shaft portion extends partially over a cutting face of the inner rotatable cutting element. 
     
     
       16. The cutting structure of  claim 12 , wherein at least a portion of a bearing surface of the outer support element comprises a lubricious material. 
     
     
       17. The cutting structure of  claim 12 , wherein the outer support element is integral with a cutting tool body. 
     
     
       18. The cutting structure of  claim 12 , wherein at least a side portion of the outer support element is a blade of a cutting tool. 
     
     
       19. The cutting structure of  claim 12 , wherein the outer support element is a discrete element. 
     
     
       20. A drill bit, comprising:
 a bit body having a plurality of blades extending radially therefrom; and   at least one cutting element of  claim 12  mounted to at least one of the plurality of blades.   
     
     
       21. A drill bit, comprising:
 a bit body having at least one radially extending blade;   at least one pocket formed in the at least one radially extending blade, and   at least one rolling element having a cylindrical body with a substantially constant diameter along its entire length retained in the at least one pocket, such that the at least one rolling element is free to rotate about an axis of the rolling element;   wherein the pocket comprises a shaft that extends into an inner cylindrical surface of the rolling element.   
     
     
       22. The drill bit of claim 21, wherein the at least one rolling element comprises a plurality of surface alterations comprising serrations extending from a radial midpoint to a cutting edge of the rolling element. 
     
     
       23. The drill bit of claim 21, wherein the rolling element is rotatably attached to the pocket by at least one retention ball. 
     
     
       24. The drill bit of claim 23, wherein corresponding grooves are formed in the inner cylindrical surface of the rolling element and an outer surface of the shaft, and the at least one retention ball is disposed in a space defined by the corresponding grooves. 
     
     
       25. The drill bit of claim 21, further comprising an inner cylindrical bearing surface between the shaft and the rolling element. 
     
     
       26. The drill bit of claim 21, wherein the pocket partially encases a bottom portion of the rolling element. 
     
     
       27. The drill bit of claim 26, further comprising an outer cylindrical bearing surface between an outer surface of the rolling element and a surface of the pocket partially encasing the rolling element. 
     
     
       28. A cutting structure, comprising:
 a support element;   a rotatable cutting element rotatably attached to the support element, such that the rotatable cutting element is allowed to rotate relative to the support element while attached to the support element;   an internal bore extending through the cutting structure, the internal bore being configured to direct a flow of fluid through and exiting the cutting structure.   
     
     
       29. The cutting structure of claim 28, wherein the internal bore extends through a bottom portion of the support element. 
     
     
       30. The cutting structure of claim 28, wherein the rotatable cutting element is rotatably attached to the support element by at least one retention ball located within a space defined by matching grooves in the support element and the rotatable cutting element. 
     
     
       31. The cutting structure of claim 28, wherein a cutting edge of the rotatable cutting element comprises polycrystalline diamond. 
     
     
       32. The cutting structure of claim 31, wherein the support element is integral with a cutting tool body. 
     
     
       33. A cutting structure, comprising:
 a support element; and   a rotatable cutting element rotatably attached to the support element, such that the rotatable cutting element is allowed to rotate relative to the support element while attached to the support element,   the rotatable cutting element having a polycrystalline diamond cutting face, wherein the rotatable cutting element has a bore that extends through the diamond cutting face.   
     
     
       34. The cutting structure of claim 33, wherein the support element is integral with a cutting tool body. 
     
     
       35. The cutting structure of claim 33, wherein the rotatable cutting element is rotatably attached to the support element by a plurality of retention balls. 
     
     
       36. The cutting structure of claim 33, wherein the support element comprises a shaft that extends into the bore. 
     
     
       37. The cutting structure of claim 36, wherein the shaft extends axially above the diamond cutting face. 
     
     
       38. A cutting structure, comprising:
 a support element; and   a rotatable cutting element rotatably attached to the support element by at least one retention ball disposed within a space defined by corresponding grooves in the support element and the rotatable cutting element,   wherein the support element comprises an inner shaft that extends into an inner cylindrical surface of the rotatable cutting element.   
     
     
       39. The cutting structure of claim 38, wherein the corresponding grooves are formed in the inner cylindrical surface of the rotatable cutting element and an outer surface of the shaft. 
     
     
       40. The cutting structure of claim 38, further comprising an inner cylindrical bearing surface between the shaft and the rotatable cutting element. 
     
     
       41. The cutting structure of claim 38, wherein the support element at least partially encases the rotatable cutting element. 
     
     
       42. The cutting structure of claim 41, further comprising an outer cylindrical bearing surface between an outer surface of the rotatable cutting element and the support element encasing the rotatable cutting element. 
     
     
       43. The cutting structure of claim 38, wherein the rotatable cutting element extends axially above the support element. 
     
     
       44. The cutting structure of claim 38, wherein the support element is integral with a cutting tool body. 
     
     
       45. A cutting structure, comprising:
 a support element on a drill bit; and   a rotatable cutting element rotatably attached to the support element;   wherein the support element comprises an inner shaft that extends entirely through the rotatable cutting element, the inner shaft having an axial length greater than the rotatable cutting element.