Abstract: A roller-mill bit for use in a wellbore includes: a body having a coupling formed at an upper end thereof and a plurality of lower legs; a plurality of roller disks, each roller disk secured to a bearing shaft of a respective leg for rotation relative thereto; a row of crushers mounted around each roller disk; and a fixed mill mounted to the bearing shafts and comprising a pad for each roller disk. Each pad is dressed with a cermet material.

Abstract: A method of manufacturing a roller cone for a drill bit includes: selectively carburizing a land of the roller cone between a plurality of spots on the land for protection against erosion; after carburization, forming sockets in the roller cone at the spots; and mounting cermet inserts in the sockets.

Abstract: A method of manufacturing a roller cone for a drill bit includes: selectively carburizing a land of the roller cone between a plurality of spots on the land for protection against erosion; after carburization, forming sockets in the roller cone at the spots; and mounting cermet inserts in the sockets.

Abstract: A drill tool includes a cone mounted for rotation on a bearing shaft that extends from a bit head. The cone has a first planar base surface opposed to a second planar base surface of the bit head. A first annular groove is formed in the first planar base surface, and a second annular groove is formed in the second planar base surface. The first and second annular grooves are at least partially aligned with each other. The combination of the first and second annular grooves form a first annular gland. A protector ring is inserted into the first annular gland, and functions to divide a fluid path between the bearing shaft of the drill tool and an external environment into a plurality of parallel fluid paths that pass around the protector ring. Each parallel fluid path includes a convolution defined by a plurality of fluid direction changing corners.

Abstract: A drill tool comprises includes a bit body, at least one bearing shaft extending from the bit body and a cone mounted for rotation on the bearing shaft. The bearing system for the tool includes a radial thrust bearing from which cone pumping pressure pulsation originates. A lubricant sealing system including an annular seal gland and a seal ring retained within the annular seal gland functions to retain lubricant in the bearing system. The tool further includes a lubricant cone pumping pressure restrictor system formed by an annular gland (separate from the annular seal gland) and a pressure restricting ring retained within the annular gland. The lubricant cone pumping pressure restrictor system is positioned between the radial thrust bearing system and the lubricant sealing system and is adapted to attenuate cone pumping lubricant pressure pulsation from acting on the seal ring retained within the annular seal gland.

Abstract: A drill tool includes a bit body, at least one bearing shaft extending from the bit body and a cone mounted for rotation on the bearing shaft. An outer bearing surface of the bearing shaft includes a non-loading zone. A first groove and a second groove are formed in the outer bearing surface at the non-loading zone. The first and second grooves are both circumferentially offset from each other and axially offset from each other. One or more of the grooves includes an opening for making a fluid connection to an internal lubricant channel within this bearing shaft. The circumferential and axial offsetting of the first and second grooves define a plurality of attenuation zones that function to restrict propagation of a cone pumping pressure pulse towards a sealing system of the drill tool.

Abstract: A drill bit includes a bit head and a rotating bit cone. A sealing system for the drill bit includes a seal gland and a seal retained within the seal gland. The seal gland is defined by a radial cone surface, a head sealing surface and an opposed cone sealing surface. At least one of the head sealing surface and opposed cone sealing surface is not cylindrical (i.e., the surface is conical and not parallel to an axis of rotation for the cone). Additionally, the radial cone surface may be conical (i.e., the surface does not extend perpendicular to the axis of rotation of the cone). The seal is radially compressed between the head sealing surface and the opposed cone sealing surface. The use of one or more conical surfaces in the gland is provided to bias the compressed seal into a preferred dynamic sealing zone.

Abstract: A drill bit includes a bit head and a rotating bit cone. A sealing system for the drill bit includes a seal gland and a seal retained within the seal gland. The seal gland is defined by a radial cone surface, a head sealing surface and an opposed cone sealing surface. At least one of the head sealing surface and opposed cone sealing surface is not cylindrical (i.e., the surface is conical and not parallel to an axis of rotation for the cone). Additionally, the radial cone surface may be conical (i.e., the surface does not extend perpendicular to the axis of rotation of the cone). The seal is radially compressed between the head sealing surface and the opposed cone sealing surface. The use of one or more conical surfaces in the gland is provided to bias the compressed seal into a preferred dynamic sealing zone.

Abstract: A drill tool includes a cone mounted for rotation on a bearing shaft that extends from a bit head. The cone has a first planar base surface opposed to a second planar base surface of the bit head. A first annular groove is formed in the first planar base surface, and a second annular groove is formed in the second planar base surface. The first and second annular grooves are at least partially aligned with each other. The combination of the first and second annular grooves form a first annular gland. A protector ring is inserted into the first annular gland, and functions to divide a fluid path between the bearing shaft of the drill tool and an external environment into a plurality of parallel fluid paths that pass around the protector ring. Each parallel fluid path includes a convolution defined by a plurality of fluid direction changing corners.

Abstract: A drill tool comprises includes a bit body, at least one bearing shaft extending from the bit body and a cone mounted for rotation on the bearing shaft. The bearing system for the tool includes a radial thrust bearing from which cone pumping pressure pulsation originates. A lubricant sealing system including an annular seal gland and a seal ring retained within the annular seal gland functions to retain lubricant in the bearing system. The tool further includes a lubricant cone pumping pressure restrictor system formed by an annular gland (separate from the annular seal gland) and a pressure restricting ring retained within the annular gland. The lubricant cone pumping pressure restrictor system is positioned between the radial thrust bearing system and the lubricant sealing system and is adapted to attenuate cone pumping lubricant pressure pulsation from acting on the seal ring retained within the annular seal gland.

Abstract: A drill tool includes a bit body, at least one bearing shaft extending from the bit body and a cone mounted for rotation on the bearing shaft. An outer bearing surface of the bearing shaft includes a non-loading zone. A first groove and a second groove are formed in the outer bearing surface at the non-loading zone. The first and second grooves are both circumferentially offset from each other and axially offset from each other. One or more of the grooves includes an opening for making a fluid connection to an internal lubricant channel within this bearing shaft. The circumferential and axial offsetting of the first and second grooves define a plurality of attenuation zones that function to restrict propagation of a cone pumping pressure pulse towards a sealing system of the drill tool.

Abstract: A rock bit includes a shaft and a cone mounted for rotation about the shaft at a journal bearing. A seal gland for the rock bit is defined at least by the shaft and the cone. A compressible seal ring is positioned within the seal gland. A thermal insulating ring is installed within the seal gland and positioned between the compressible seal ring itself and the journal bearing to insulate the compressible seal ring from heat radiating from the journal bearing.

Abstract: A rock bit includes a shaft and a cone mounted for rotation about the shaft at a journal bearing. A seal gland for the rock bit is defined at least by the shaft and the cone. A compressible seal ring is positioned within the seal gland. A thermal insulating ring is installed within the seal gland and positioned between the compressible seal ring itself and the journal bearing to insulate the compressible seal ring from heat radiating from the journal bearing.

Abstract: A rock bit includes a shaft and a cone mounted for rotation about the shaft at a journal bearing. A seal gland for the rock bit is defined at least by the shaft and the cone. A compressible seal ring is positioned within the seal gland. A thermal insulating ring is installed within the seal gland and positioned between the compressible seal ring itself and the journal bearing to insulate the compressible seal ring from heat radiating from the journal bearing.

Abstract: A sealing system is provided for a drill bit including a bit head and a rotating bit cone. The sealing system includes a seal gland and a seal retained within the seal gland. The seal gland is defined by a radial cone surface and is further defined by a head sealing surface and an opposed cone sealing surface. At least one of the head sealing surface and opposed cone sealing surface is not cylindrical (i.e., the surface is conical and not parallel to an axis of rotation for the cone). Additionally, the radial cone surface may be conical (i.e., the surface does not extend perpendicular to the axis of rotation of the cone). The seal is radially compressed between the head sealing surface and the opposed cone sealing surface. The use of one or more conical surfaces in the gland is provided to bias the compressed seal into a preferred dynamic sealing zone.

Abstract: A sealing system is provided for a drill bit including a bit head and a rotating bit cone. The sealing system includes a seal gland and a seal retained within the seal gland. The seal gland is defined by a radial cone surface and is further defined by a head sealing surface and an opposed cone sealing surface. At least one of the head sealing surface and opposed cone sealing surface is not cylindrical (i.e., the surface is conical and not parallel to an axis of rotation for the cone). Additionally, the radial cone surface may be conical (i.e., the surface does not extend perpendicular to the axis of rotation of the cone). The seal is radially compressed between the head sealing surface and the opposed cone sealing surface. The use of one or more conical surfaces in the gland is provided to bias the compressed seal into a preferred dynamic sealing zone.

Abstract: A drill bit includes a bit head and a rotating bit cone. A sealing system for the drill bit includes a seal gland and a seal retained within the seal gland. The seal gland is defined by a radial cone surface, a head sealing surface and an opposed cone sealing surface. At least one of the head sealing surface and opposed cone sealing surface is not cylindrical (i.e., the surface is conical and not parallel to an axis of rotation for the cone). Additionally, the radial cone surface may be conical (i.e., the surface does not extend perpendicular to the axis of rotation of the cone). The seal is radially compressed between the head sealing surface and the opposed cone sealing surface. The use of one or more conical surfaces in the gland is provided to bias the compressed seal into a preferred dynamic sealing zone.

Abstract: A rock bit includes a shaft and a cone mounted for rotation about the shaft at a journal bearing. A seal gland for the rock bit is defined at least by the shaft and the cone. A compressible seal ring is positioned within the seal gland. A thermal insulating ring is installed within the seal gland and positioned between the compressible seal ring itself and the journal bearing to insulate the compressible seal ring from heat radiating from the journal bearing.

Abstract: A sealing system is provided for a drill bit including a bit head and a rotating bit cone. The sealing system includes a seal gland and a seal retained within the seal gland. The seal gland is defined by a radial cone surface and is further defined by a head sealing surface and an opposed cone sealing surface. At least one of the head sealing surface and opposed cone sealing surface is not cylindrical (i.e., the surface is conical and not parallel to an axis of rotation for the cone). Additionally, the radial cone surface may be conical (i.e., the surface does not extend perpendicular to the axis of rotation of the cone). The seal is radially compressed between the head sealing surface and the opposed cone sealing surface. The use of one or more conical surfaces in the gland is provided to bias the compressed seal into a preferred dynamic sealing zone.