Disc Cutter for an Earth Boring System
In one aspect of the present invention a disc cutter for an earth boring system includes an axle and a sintered polycrystalline ceramic disc disposed about and forming a continuous perimeter around the axle. The disc cutter may be attached to a drill bit comprising a body, working face and plurality of blades. Another aspect of the present invention comprises a method of forming a disc cutter including providing a can of a generally cylindrical shape with a central axis, positioning a column of disposable material, carbide, and crystalline grains in such a manner so when put under high temperature and high pressure a compact in the shape of a disc cutter may be formed and a column from the center axis may be removed. Another method for forming a disc cutter comprises forming a plurality of compacts and bonding the compacts together in a generally toroidal shape.
1 . A disc cutter for an earth boring system, comprising:
an axle;
a sintered polycrystalline ceramic disc disposed about the axle; and
the ceramic disc forming a continuous perimeter around the axle.
2 . The disc cutter of claim 1 , wherein the axle comprises a polycrystalline ceramic layer disposed on an exterior surface of the axle.
3 . The disc cutter of claim 1 , wherein the sintered polycrystalline ceramic disc is composed of a uniform polycrystalline ceramic material.
4 . The disc cutter of claim 1 , wherein the sintered polycrystalline ceramic disc comprises a carbide core proximate the axle and a sintered polycrystalline ceramic external layer bonded to the carbide core.
5 . The disc cutter of claim 4 , wherein the carbide core comprises a polycrystalline ceramic interior layer proximate the axle.
6 . The disc cutter of claim 1 , wherein the sintered polycrystalline ceramic disc is freely rotatable about the axle
7 . The disc cutter of claim 1 , wherein the sintered polycrystalline ceramic disc is fixed to the axle.
8 . The disc cutter of claim 1 , wherein the sintered polycrystalline ceramic disc comprises grooves.
9 . The disc cutter of claim 8 , wherein the grooves originate from a rim of the sintered polycrystalline ceramic disc and terminate at the axle.
10 . The disc cutter of claim 8 , wherein the grooves are continuous around the axle.
11 . The disc cutter of claim 1 , wherein the sintered polycrystalline ceramic disc comprises protrusions extending from and adding texture to the ceramic disc.
12 . The disc cutter of claim 1 , wherein the sintered polycrystalline ceramic disc comprises two parallel cutting edges comprising supplemental internal angles.
13 . The disc cutter of claim 1 , wherein the disc comprises a rim comprising an internal angle measuring 80 to 140 degrees between two parallel cutting edges each comprising an internal angle greater than 90 degrees.
14 . The disc cutter of claim 13 , wherein the sintered polycrystalline ceramic disc comprises a carbide core and a distance from at least one cutting edge to the carbide core is equal to a distance from the rim to the carbide core.
15 . The disc cutter of claim 1 , further comprising a plurality of sintered polycrystalline ceramic discs.
16 . A drill bit for penetrating earthen formations, comprising:
a body comprising a working face;
the working face comprising a plurality of blades converging toward a center of the working face and diverging toward a gauge of the working face;
an axle bonded to one of the plurality of blades; and
a sintered polycrystalline ceramic disc disposed about the axle and the disc forming a continuous perimeter around the axle.
17 . The drill bit of claim 16 , further comprising at least one shear cutter disposed on one of the plurality of blades.
18 . The drill bit of claim 16 , wherein the axle is bonded to one of the plurality of blades at the gauge of the working face.
19 . The drill bit of claim 16 , wherein the sintered polycrystalline ceramic disc is aligned tangent to a periphery of the working face.
20 . The drill bit of claim 16 , wherein the sintered polycrystalline ceramic disc is aligned perpendicular to the working face.