Abstract: An earth-boring tool having at least one cutting element with a multi-friction cutting face provides for the steering of formation cuttings as the cuttings slide across the cutting face. The multi-friction cutting element includes a diamond table bonded to a substrate of superabrasive material. The diamond table has a cutting face formed thereon with a cutting edge extending along a periphery of the cutting face. The cutting face has a first area having an average surface finish roughness less than an average surface finish roughness of a second area of the cutting face, the two areas separated by a boundary having a proximal end proximate a tool crown and a distal end remote from the tool crown.

Abstract: An earth boring bit has a bit body with a depending bearing pin, a cone rotatably mounted on the bearing pin, a seal gland between the cone and the bearing pin, and a seal assembly located in the seal gland. The seal assembly includes an annular metallic spring encircling the bearing pin. The spring has a geometric center line that extends in a circle around the bearing pin. The spring is elastically deformable in radial directions relative to the center line. An elastomeric layer is located on an exterior side of the spring and is biased by the spring against a surface of the seal gland.

Abstract: An earth-boring tool having at least one cutting element with a multi-friction cutting face provides for the steering of formation cuttings as the cuttings slide across the cutting face. The multi-friction cutting element includes a diamond table bonded to a substrate of superabrasive material. The diamond table has a cutting face formed thereon with a cutting edge extending along a periphery of the cutting face. The cutting face has a first area having an average surface finish roughness less than an average surface finish roughness of a second area of the cutting face, the two areas separated by a boundary having a proximal end proximate a tool crown and a distal end remote from the tool crown.

Abstract: Downhole tools for earth-boring applications may include a component of a steel material and including a bore. An inner surface defining the bore may be treated with a surface treatment. The surface treatment may include a nitrided region having nitrogen diffused into the steel material and a ceramic material adjacent to the nitrided region; the ceramic material defining the inner surface. Methods of making downhole tools for earth-boring applications may involve exposing a component of the downhole tool to an elevated temperature to heat the component in a nitrogen-rich environment. Nitrogen may be diffused into a steel material of the component and a nitrided region may be formed at one or more surfaces of the component. A ceramic material may be coated on the nitrided region of the component.

Abstract: An earth-boring tool having at least one cutting element with a multi-friction cutting face provides for the steering of formation cuttings as the cuttings slide across the cutting face. The multi-friction cutting element includes a diamond table bonded to a substrate of superabrasive material. The diamond table has a cutting face formed thereon with a cutting edge extending along a periphery of the cutting face. The cutting face has a first area having an average surface finish roughness less than an average surface finish roughness of a second area of the cutting face, the two areas separated by a boundary having a proximal end proximate a tool crown and a distal end remote from the tool crown.

Abstract: Bearings for downhole tools including a first bearing member and a second bearing member, at least one of the first and second bearing members having a channel formed therein. Methods of cooling bearings of downhole tools comprise flowing a fluid within a channel formed in at least one bearing member. Heat is transferred from at least the at least one bearing member to the fluid. The fluid is flowed away from the at least one bearing member.

Abstract: Downhole tools for earth-boring applications may include a component of a steel material and including a bore. An inner surface defining the bore may be treated with a surface treatment. The surface treatment may include a nitrided region having nitrogen diffused into the steel material and a ceramic material adjacent to the nitrided region; the ceramic material defining the inner surface. Methods of making downhole tools for earth-boring applications may involve exposing a component of the downhole tool to an elevated temperature to heat the component in a nitrogen-rich environment. Nitrogen may be diffused into a steel material of the component and a nitrided region may be formed at one or more surfaces of the component. A ceramic material may be coated on the nitrided region of the component.

Abstract: Downhole motors include a stator, which may be formed from a steel material and comprise a bore. At least one surface of the stator may be treated with a surface treatment. The surface treatment includes a nitrided region comprising nitrogen diffused into the steel material and a ceramic material adjacent to the nitrided region; the ceramic material defining an interior surface of the stator defining the bore. Methods of making downhole motors may include exposing a stator to an elevated temperature to heat the stator in a nitrogen-rich environment. Nitrogen may be diffused into a steel material of the stator and a nitrided region may be formed at one or more surfaces of the stator. The stator may be cooled. The stator may be removed from the nitrogen-rich environment. A ceramic material may be coated on the nitrided region of the stator.

Abstract: An earth-boring tool having at least one cutting element with a multi-friction cutting face provides for the steering of formation cuttings as the cuttings slide across the cutting face. The multi-friction cutting element includes a diamond table bonded to a substrate of superabrasive material. The diamond table has a cutting face formed thereon with a cutting edge extending along a periphery of the cutting face. The cutting face has a first area having an average surface finish roughness less than an average surface finish roughness of a second area of the cutting face, the two areas separated by a boundary having a proximal end proximate a tool crown and a distal end remote from the tool crown.

Abstract: An earth boring bit has a bit body with a depending bearing pin, a eons rotatably mounted on the hearing pin, a seal gland between the cone and the bearing pin, and a seal assembly located in the seal gland. The seal assembly includes an annular metallic spring encircling the bearing pin. The spring has a geometric center line that extends in a circle around the bearing pin. The spring is elastically deform able in radial directions relative to the center line. An elastomeric layer is located on an exterior side of the spring and is biased by the spring against a surface of the seal gland.

Abstract: An earth-boring tool having at least one cutting element with a multi-friction cutting face provides for the steering of formation cuttings as the cuttings slide across the cutting face. The multi-friction cutting element includes a diamond table bonded to a substrate of superabrasive material. The diamond table has a cutting face formed thereon with a cutting edge extending along a periphery of the cutting face. The cutting face has a first area having an average surface finish roughness less than an average surface finish roughness of a second area of the cutting face, the two areas separated by a boundary having a proximal end proximate a tool crown and a distal end remote from the tool crown.

Abstract: An earth boring bit has a bit body with a depending bearing pin, a cone rotatably mounted on the bearing pin, a seal gland between the cone and the bearing pin, and a seal assembly located in the seal gland. The seal assembly includes an annular metallic spring encircling the bearing pin. The spring has a geometric center line that extends in a circle around the bearing pin. The spring is elastically deformable in radial directions relative to the center line. An elastomeric layer is located on an exterior side of the spring and is biased by the spring against a surface of the seal gland.

Abstract: Downhole motors include a stator, which may be formed from a steel material and comprise a bore. At least one surface of the stator may be treated with a surface treatment. The surface treatment includes a nitrided region comprising nitrogen diffused into the steel material and a ceramic material adjacent to the nitrided region; the ceramic material defining an interior surface of the stator defining the bore. Methods of making downhole motors may include exposing a stator to an elevated temperature to heat the stator in a nitrogen-rich environment. Nitrogen may be diffused into a steel material of the stator and a nitrided region may be formed at one or more surfaces of the stator. The stator may be cooled. The stator may be removed from the nitrogen-rich environment. A ceramic material may be coated on the nitrided region of the stator.

Abstract: Bearings for downhole tools including a first bearing member and a second bearing member, at least one of the first and second bearing members having a channel formed therein. Methods of cooling bearings of downhole tools comprise flowing a fluid within a channel formed in at least one bearing member. Heat is transferred from at least the at least one bearing member to the fluid. The fluid is flowed away from the at least one bearing member.

Abstract: An earth-boring tool having at least one cutting element with a multi-friction cutting face provides for the steering of formation cuttings as the cuttings slide across the cutting face. The multi-friction cutting element includes a diamond table bonded to a substrate of superabrasive material. The diamond table has a cutting face formed thereon with a cutting edge extending along a periphery of the cutting face. The cutting face has a first area having an average surface finish roughness less than an average surface finish roughness of a second area of the cutting face, the two areas separated by a boundary having a proximal end proximate the tool crown and a distal end remote from the tool crown.

Abstract: An earth boring bit has a bit body with a depending bearing pin, a cone rotatably mounted on the bearing pin, a seal gland between the cone and the bearing pin, and a seal assembly located in the seal gland. The seal assembly includes an annular metallic spring encircling the bearing pin. The spring has a geometric center line that extends in a circle around the bearing pin. The spring is elastically deformable in radial directions relative to the center line. An elastomeric layer is located on an exterior side of the spring and is biased by the spring against a surface of the seal gland.

Abstract: An elastomeric seal ring is located between each bearing pin and each cone of an earth-boring bit. An auxiliary ring or band is imbedded within an annular recess formed in the inner diameter of the seal ring. A portion of the inner diameter of the seal ring as well as the auxiliary ring are in dynamic contact with the bearing pin. The auxiliary ring has a geometric feature that enhances radial flexibility but prevents it from sealing. The geometric feature may be a transverse cut, notches in either the inner or outer diameters, or holes extending between the sides of the auxiliary ring. The auxiliary ring has lubricating properties.

Abstract: An elastomeric seal ring is located between each bearing pin and each cone of an earth-boring bit. An excluder ring or band is imbedded within the inner diameter of the seal ring. A portion of the inner diameter of the seal ring as well as the excluder ring are in dynamic sealing contact with the bearing pin. The excluder ring may be harder and more wear resistant than the seal ring. The excluder ring may have lubricating properties. An outer excluder ring may be located on the outer diameter of the seal ring for engaging the cone to resist rotation.

Abstract: A composite seal gland insert for a roller cone rock bit is a polymer composite sleeve containing one or more constituents that function to significantly lower the wear of the elastomeric seal ring. A fluid lubricant film also may be used between the elastomer seal and the gland. The outer surface of the insert is profiled to provide a sealing surface against which the elastomer seal runs. The insert is installed over the bearing pin and has a surface that engages the last machined surface of the leg. A static seal, which may comprise an additional elastomeric seal, may be used beneath the gland insert to provide a pressure seal between the insert and the pin. An adhesive also may be used as the pressure seal and also to retain the gland insert in the desired position. In addition, a mechanical anti-rotation device may be used to prevent rotation of the gland insert.

Abstract: A roller cone bit is provided that includes a wear resistant diamond-like carbon coating applied to a bearing shaft, where it is in sliding contact with the bearing seal. The wear resistant diamond-like carbon coating reduces wear and corrosion of the head bearing shaft sealing surface and provides extended life to the bearing seal.