1. A hydrodynamic bearing assembly, comprising:
a support ring including a common slot; and
a plurality of discrete bearing elements distributed circumferentially about an axis and brazed to the support ring within the common slot with a braze alloy, each of the discrete bearing elements including a superhard bearing surface and extending beyond the common slot and the support ring, the plurality of discrete bearing elements defining a plurality of gaps, each of the gaps being located between circumferentially-adjacent discrete bearing elements of the plurality of discrete bearing elements with the braze alloy at least partially filling each of the gaps, at least a portion of the gaps being about 0.0051 mm to about 2.54 mm.
2. The hydrodynamic bearing assembly of claim 1 wherein the at least a portion of the gaps is about 0.0051 mm to about 0.051 mm.
3. The hydrodynamic bearing assembly of claim 1 wherein each of the discrete bearing elements comprises a first end region and a second end region with a respective one of the superhard bearing surfaces extending therebetween.
4. The hydrodynamic bearing assembly of claim 3 wherein the first end region and the second end region of each of the discrete bearing elements each comprises a substantially planar side surface.
5. The hydrodynamic bearing assembly of claim 4 wherein the substantially planar side surface is substantially oriented in a reference plane in which the axis substantially lies.
6. The hydrodynamic bearing assembly of claim 3 wherein the first end region and the second end region of each of the discrete bearing elements each exhibits a selected non-planar geometry.
7. The hydrodynamic bearing assembly of claim 6 wherein the selected non-planar geometry comprises a serrated geometry.
8. The hydrodynamic bearing assembly of claim 1 wherein at least a portion of the discrete bearing elements comprises a curved radial inner surface, a curved radial outer surface, a first substantially planar side surface extending between the curved radial inner surface and the curved radial outer surface, a second substantially planar side surface extending between the curved radial inner surface and the curved radial outer surface, with a respective one of the superhard bearing surfaces extending between the curved radial inner surface, the curved radial outer surface, the first substantially planar side surface, and the second substantially planar side surface.
9. The hydrodynamic bearing assembly of claim 1 wherein the superhard bearing surfaces form a substantially continuous bearing surface.
10. The hydrodynamic bearing assembly of claim 1 wherein the axis is a thrust axis.
11. The hydrodynamic bearing assembly of claim 1 wherein the axis is a rotation axis.
12. The hydrodynamic bearing assembly of claim 1 wherein each of the discrete bearing elements comprises:
a substrate; and
a superhard table bonded to the substrate, the superhard table including a respective one of the superhard bearing surfaces.
13. The hydrodynamic bearing assembly of claim 12 wherein the superhard table comprises at least one material selected from the group consisting of polycrystalline diamond, cubic boron nitride, and a diamond-silicon carbide composite.
14. The hydrodynamic bearing assembly of claim 1 wherein the braze alloy substantially fills each of the gaps.
15. A hydrodynamic bearing apparatus, comprising:
a rotor including a plurality of circumferentially-spaced bearing elements each of which includes a first bearing surface; and
a stator including a support ring including a common slot, the stator including a plurality of discrete bearing elements distributed circumferentially about an axis and brazed to the support ring within the single slot with a braze alloy, each of the discrete bearing elements including a superhard bearing surface and extending beyond the common slot and the support ring, the superhard bearing surfaces of the discrete bearing elements oriented to generally oppose the first bearing surfaces of the plurality of circumferentially-spaced bearing elements of the rotor, the plurality of discrete bearing elements defining a plurality of gaps, each of the gaps being located between circumferentially-adjacent discrete bearing elements of the plurality of discrete bearing elements with the braze alloy at least partially filling each of the gaps, at least a portion of the gaps being about 0.0051 mm to about 2.54 mm.
16. The hydrodynamic bearing assembly of claim 15 wherein the braze alloy substantially fills each of the gaps.
17. A motor assembly for use in drilling subterranean formations, comprising:
a motor operable to apply torque to a rotary drill bit, the motor operably coupled to a hydrodynamic bearing apparatus, the hydrodynamic bearing apparatus including a rotor and a stator; and
wherein at least one of the stator or the rotor comprises a hydrodynamic bearing assembly including:
a plurality of discrete bearing elements distributed circumferentially about an axis, the plurality of discrete bearing elements brazed to a support ring within a common slot thereof, each of the discrete bearing elements including a superhard bearing surface and extending beyond the common slot and the support ring, the plurality of discrete bearing elements defining a plurality of gaps, each of the gaps being located between circumferentially-adjacent discrete bearing elements of the plurality of discrete bearing elements with the braze alloy at least partially filling each of the gaps, at least a portion of the gaps being about 0.0051 mm to about 2.54 mm.
18. The hydrodynamic bearing assembly of claim 17 wherein the braze alloy substantially fills each of the gaps.
19. A hydrodynamic bearing assembly, comprising:
a support ring including a common slot;
a plurality of discrete polycrystalline diamond bearing elements distributed circumferentially in a single substantially circular row about a thrust axis and brazed to the support ring within the common slot with a braze alloy, each of the discrete polycrystalline diamond bearing elements including a polycrystalline diamond bearing surface and extending beyond the common slot and the support ring, the plurality of discrete polycrystalline diamond bearing elements defining a plurality of gaps, each of the gaps being located between circumferentially-adjacent discrete polycrystalline diamond bearing elements of the plurality of discrete polycrystalline diamond bearing elements with the braze alloy at least partially filling each of the gaps, at least a portion of the gaps being about 0.0051 mm to about 2.54 mm; and
wherein each of the discrete bearing elements includes a curved radial inner surface, a curved radial outer surface, a first substantially planar side surface extending between the curved radial inner surface and the curved radial outer surface, a second substantially planar side surface extending between the curved radial inner surface and the curved radial outer surface, with a respective one of the polycrystalline diamond bearing surfaces extending between the curved radial inner surface, the curved radial outer surface, the first substantially planar side surface, and the second substantially planar side surface.
20. The hydrodynamic bearing assembly of claim 19 wherein the braze alloy substantially fills each of the gaps.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A negative active material for a rechargeable lithium battery comprising:
particles of a carbonaceous material that are capable of reversibly intercalating and deintercalating lithium; and
particles of a metal or a metal compound or mixtures thereof, distributed within the particles of carbonaceous material, wherein the particles of the metal or the metal compound have an average particulate diameter of 20 to 500 nm, the metal or the metal compound forming an alloy with lithium during electrochemical charging and discharging.
2. The negative active material of claim 1, wherein the metal or the metal compound is represented by formula 1:
A1\u2212xBx\u2003\u2003(1)
where 0\u2266x\u22660.%
A is at least one selected from the group consisting of Sn, Si, Ag, Zn, Cd, Al, Ga, In, Ce, Pb, As, Bi, and Sb; and
B is at least one selected from the group consisting of Zr, Ti, Fe, Co, Ni, Cu, C, O, N, and S.
3. The negative active material of claim 2, wherein x is in the range of 0 to 0.5.
4. The negative active material of claim 2, wherein the metal compound is an oxide of Sn, an oxide of Si, or an oxide of Sb.
5. The negative active material of claim 1, wherein the metal or the metal compound has an amorphous or a crystalline structure.
6. The negative active material of claim 1, wherein the particles of carbonaceous material having the particles of the metal or the metal compound or mixtures thereof distributed within have an average particulate diameter of 10 to 100 \u03bcm.
7. The negative active material of claim 6, wherein the particles of carbonaceous material havina the particles of the metal or the metal compound or mixtures thereof distributed within have an average particulate diameter of 20 to 50 \u03bcm.
8. The negative active material of claim 1, wherein the particles of the metal or the metal compound have an average particulate diameter of 20 to 80 nm.
9. The negative active material of claim 1, wherein the negative active material includes 10 to 80 wt % of the metal or the metal compound.
10. The negative active material of claim 1, wherein the ratio of the diameter of the particles of the metal or the metal compound to the diameter of the particles of carbonaceous material having the particles of the metal or the metal compound or mixtures thereof distributed therein have is 20 or less.
11. The negative active material of claim 1, wherein the negative active material includes an oxide layer formed on the metal or the metal compound.
12. The negative active material of claim 11, wherein the oxide layer has a thickness of 10 \u212b or less.
13. The negative active material of claim 1, wherein the particles of carbonaceous material having the particles of the metal or the metal compound or mixtures thereof distributed therein have a spherical shape or an elliptical shape.
14. The negative active material of claim 1, wherein the carbonaceous material is amorphous carbon.
15. The negative active material of claim 1, wherein the particles of carbonaceous material having the particles of the metal or the metal compound or mixtures thereof distributed therein have a core-shell structure, and the shell has a higher intensity ratio of Raman Spectroscopy peak intensity than the core.
16. The negative active material of claim 15, wherein the shell has an intensity ratio Ra I(1360)1(1580) of a Raman Spectroscopy peak intensity I(1360) at a (1360) plane to an Raman Spectroscopy peak intensity I(1580) at a (1580) plane of 0.2 to 1.5.
17. A rechargeable lithium battery comprising:
a positive electrode comprising a positive active material which reversibly intercalates and deintercalates lithium;
a negative electrode including a negative active material;
a separator interposed between the positive electrode and the negative electrode; and
an electrolyte comprising a non-aqueous organic solvent and a lithium salt; and wherein the negative active material comprises:
particles of a carbonaceous material that reversibly intercalate and deintercalate lithium, and
a plurality of particles of a metal or a metal compound or mixtures thereof, distributed within the particles of the carbonaceous material, wherein the particles of the metal or the metal compound have an average particulate diameter of 20 to 500 nm, the metal or the metal compound being capable of forming an alloy with lithium during electrochemical charging and discharging.
18. The rechargeable lithium battery of claim 17, wherein the non-aqueous organic solvent is at least one selected from the group consisting of carbonates, esters, ethers, and ketones.
19. The rechargeable lithium battery of claim 17, wherein the metal or the metal compound is represented by formula 1:
A1\u2212xBx\u2003\u2003(1)
where 0\u2266x\u22660.9;
A is at least one selected from the group consisting of Sn, Si, Ag, Zn, Cd, Al, Ga, In, Ce, Pb, As, Bi, and Sb; and
B is at least one selected from the group consisting of Zr, Ti, Fe, Co, Ni, Cu, C, O, N, and S.
20. The rechargeable lithium battery of claim 19, wherein x is in the range of 0 to 0.5.
21. The rechargeable lithium battery of claim 19, wherein the metal compound is an oxide of Sn, an oxide of Si, or an oxide of Sb.
22. The rechargeable lithium battery of claim 17, wherein the metal or the metal compound has an amorphous or a crystalline structure.
23. The rechargeable lithium battery of claim 17, wherein the particles of carbonaceous material having the particles of the metal or the metal compound or mixtures thereof distributed within have an average particulate diameter of 10 to 100 \u03bcm.
24. The rechargeable lithium battery of claim 23, wherein the particles of carbonaceous material having the particles of the metal or the metal compound or mixtures thereof distributed within have an average particulate diameter of 20 to 50 \u03bcm.
25. The rechargeable lithium battery of claim 17, wherein the particles of the metal or the metal compound have an average particulate diameter of 20 to 80 nm.
26. The rechargeable lithium battery of claim 17, wherein the negative active material includes 10 to 80 wt % of the metal or the metal compound.
27. The rechargeable lithium battery of claim 17, wherein the ratio of the diameter of the particles of the metal or the metal compound to the diameter of the particles of carbonaceous material having the particles of the metal or the metal compound or mixtures thereof distributed within is 20 or less.
28. The rechargeable lithium battery of claim 17, wherein the negative active material includes an oxide layer formed on the metal or the metal compound.
29. The rechargeable lithium battery of claim 28, wherein the oxide layer has a thickness of 10 \u212b or less.
30. The rechargeable lithium battery of claim 17, wherein the particles of carbonaceous material having the particles of the metal or the metal compound or mixtures thereof distributed within have spherical shape or elliptical shape.
31. The rechargeable lithium battery of claim 17, wherein the carbonaceous material is amorphous carbon.
32. The rechargeable lithium battery of claim 17, wherein the particles of carbonaceous material having the particles of the metal or the metal compound or mixtures thereof distributed within have a core-shell structure, and the shell has a higher intensity ratio of Raman Spectroscopy peak intensity than the core.
33. The rechargeable lithium battery of claim 32, wherein the shell has an intensity ratio Ra I(1360)1(1580) of a Raman Spectroscopy peak intensity I(1360) at a (1360) plane to an Raman Spectroscopy peak intensity I(1580) at a (1580) plane of 0.2 to 1.5.