An earth boring bit with sealed cutter bearings has a dual function pressure compensator for a lubricant reservoir. The earth boring bit has a bit body and downwardly extending legs which include bearing shafts that extend inward and downward for mounting rotary cutters, and seals are provided between the bearing shafts and the cutters. Lubricant flow passages extend from an interior cavity of the bit body, through the legs and the bearing shafts, and into the spaces located between the bearing shafts and the cutters. The pressure compensator extends between the cavity and the flow passages and has a movable piston. The compensator may be operated in a sealed lubricant system mode when the piston is locked in place or an air flow bypass mode by removing a locking member from securing the piston in place prior to securing the earth boring bit to a drill string.

A pressure compensating lubrication system for sealed bearing earth boring bits having a lubricant reservoir fitted with a piston. A spring member is disposed between one end of the reservoir and the piston. The spring member applies pressure through the piston to the lubricant in the reservoir and bearing and absorbs pressure fluctuations in the lubricant generated while drilling.

A pressure compensating lubrication system for sealed bearing earth boring bits having a lubricant reservoir fitted with a piston. A spring member is disposed between one end of the reservoir and the piston. The spring member applies pressure through the piston to the lubricant in the reservoir and bearing and absorbs pressure fluctuations in the lubricant generated while drilling.

A rock bit for blast hole drilling includes a body having a coupling formed at an upper end thereof and a plurality of lower legs, each leg having a top base, an upper shoulder, a mid shirttail, a lower bearing shaft, a leading side, a trailing side and a ported boss, and a plurality of roller cones. Each roller cone is secured to the respective bearing shaft for rotation relative thereto. A row of crushers is mounted around each roller cone. Each leading side and each trailing side are recessed relative to the respective shirttail. Each side has a cuttings channel formed therein. The rock bit further having a nozzle disposed at each ported boss. wherein each nozzle is inclined relative to a longitudinal axis of the rock bit by an outward angle.

A rock bit for blast hole drilling includes a body having a coupling formed at an upper end thereof and a plurality of lower legs, each leg having a top base, an upper shoulder, a mid shirttail, a lower bearing shaft, a leading side, a trailing side and a ported boss, and a plurality of roller cones. Each roller cone is secured to the respective bearing shaft for rotation relative thereto. A row of crushers is mounted around each roller cone. Each leading side and each trailing side are recessed relative to the respective shirttail. Each side has a cuttings channel formed therein. The rock bit further having a nozzle disposed at each ported boss. wherein each nozzle is inclined relative to a longitudinal axis of the rock bit by an outward angle.

A bearing providing a plurality of rolling elements and at least one raceway for the rolling elements. The at least one raceway or the rolling elements include a tungsten carbide coating. In some embodiments, the tungsten carbide coating may be a Nano-structured tungsten carbide coating. In some embodiments, the at least one raceway or the rolling elements may comprise a steel substrate covered with the tungsten carbide coating. Embodiments also relate to a method for producing a bearing. The method includes coating a plurality of rolling elements or at least one raceway for the rolling elements with a tungsten carbide coating. In some embodiments, the tungsten carbide coating may be a Nano-structured tungsten carbide coating.

A bearing providing a plurality of rolling elements and at least one raceway for the rolling elements. The at least one raceway or the rolling elements include a tungsten carbide coating. In some embodiments, the tungsten carbide coating may be a Nano-structured tungsten carbide coating. In some embodiments, the at least one raceway or the rolling elements may comprise a steel substrate covered with the tungsten carbide coating. Embodiments also relate to a method for producing a bearing. The method includes coating a plurality of rolling elements or at least one raceway for the rolling elements with a tungsten carbide coating. In some embodiments, the tungsten carbide coating may be a Nano-structured tungsten carbide coating.

A cutting roller has an axle (2), on which a cutting ring (4) is rotatably guided by a bearing device (10, 12). The bearing device is sealed against the environment by a sealing device (28, 30). By a compensating device (40), any differential pressure between the bearing device (10, 12) and the environment is compensable.

A cutting roller has an axle (2), on which a cutting ring (4) is rotatably guided by a bearing device (10, 12). The bearing device is sealed against the environment by a sealing device (28, 30). By a compensating device (40), any differential pressure between the bearing device (10, 12) and the environment is compensable.

A method of utilizing a wellbore tool in a subterranean formation includes disposing a wellbore tool in a borehole. The wellbore tool has a first body and a second body. The first body is translated relative to the second body while exposing at least one surface of at least one of the first and second bodies to a lubricant comprising an organometallic compound, and a protective coating forms over the first body and/or the second body. The protective coating formed includes a metal originating from the organometallic compound. A tool for forming or servicing a wellbore includes a first body; a second body configured to translate relative to the second body; and a lubricant adjacent the first body and the second body.