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.

Various embodiments disclosed relate to bearing assembly for drilling a subterranean formation and methods of using the same. In various embodiments, the present invention provides a method of drilling a subterranean formation. The method includes flowing a drilling fluid through a drill string disposed in the subterranean formation, with the drill string including a bottom hole assembly including a bearing assembly including a low flow bearing. The method includes flowing a first part of the drilling fluid into contact with the low flow bearing, while simultaneously flowing a second part of the drilling fluid through a bypass channel around the low flow bearing. The method also includes discharging the first and second part of the drilling fluid between the bottom hole assembly and the subterranean formation.

A shank adapter, rock drilling machine and method of mounting a shank adapter of a rock drilling machine inside a slide bearing element. The shank adapter includes a coupling head and a rotation portion at its opposite ends, and a flushing portion located therebetween. Outer diameters of the coupling head and the rotation portion are both greater than outer diameters of portions of the shank adaptor located therebetween.

A shank adapter, rock drilling machine and method of mounting a shank adapter of a rock drilling machine inside a slide bearing element. The shank adapter includes a coupling head and a rotation portion at its opposite ends, and a flushing portion located therebetween. Outer diameters of the coupling head and the rotation portion are both greater than outer diameters of portions of the shank adaptor located therebetween.

The invention relates to hole forming tools suitable for use in subterranean drilling operations, operable with two non-parallel rotational motions for forming a hole of substantially circular cross section in a material, the tool comprising a rotatable drill body (17) having a proximal end (19) for attachment to a drive mechanism and a distal end (21) on which is disposed at least one rotatable cutting member (23), wherein the or each rotatable cutting member (23) independently extends away from said distal end (21); the or each rotatable cutting member (23) independently being substantially concentric with and supported by a cantilever shaft (35); wherein on the or each rotatable cutting member (23) is disposed at least one cutting structure (24), the or each cutting structure (24) independently having a cutting face with a continuous cutting edge which is substantially concentric with the axis of rotation of said rotatable cutting member (23).

The invention relates to hole forming tools suitable for use in subterranean drilling operations, operable with two non-parallel rotational motions for forming a hole of substantially circular cross section in a material, the tool comprising a rotatable drill body (17) having a proximal end (19) for attachment to a drive mechanism and a distal end (21) on which is disposed at least one rotatable cutting member (23), wherein the or each rotatable cutting member (23) independently extends away from said distal end (21); the or each rotatable cutting member (23) independently being substantially concentric with and supported by a cantilever shaft (35); wherein on the or each rotatable cutting member (23) is disposed at least one cutting structure (24), the or each cutting structure (24) independently having a cutting face with a continuous cutting edge which is substantially concentric with the axis of rotation of said rotatable cutting member (23).

An air-cooled earth-boring drill bit including a plurality of lugs. Each lug includes a pin flange. A first roller race is distal to the pin flange. A thrust flange is distal to the first roller race. At least one pin flange vent slot is arranged in a surface of the pin flange opposite the first roller race. The at least one pin flange vent slot opens in a direction of a load side of a bearing. At least one thrust flange vent slot is arranged in a surface of the thrust flange facing the first rollers. The at least one thrust flange vent slot opens in the direction of the load side of the bearing. A plurality of flow passages are arranged within the lug to supply fluid to the at least one pin flange vent slot and the at least one thrust flange vent slot.

An air-cooled earth-boring drill bit including a plurality of lugs. Each lug includes a pin flange. A first roller race is distal to the pin flange. A thrust flange is distal to the first roller race. At least one pin flange vent slot is arranged in a surface of the pin flange opposite the first roller race. The at least one pin flange vent slot opens in a direction of a load side of a bearing. At least one thrust flange vent slot is arranged in a surface of the thrust flange facing the first rollers. The at least one thrust flange vent slot opens in the direction of the load side of the bearing. A plurality of flow passages are arranged within the lug to supply fluid to the at least one pin flange vent slot and the at least one thrust flange vent slot.

A rock bit for blast hole drilling includes: a bit body having a coupling formed at an upper end thereof, a plurality of lower legs, a dome formed between the legs, and a bore formed through the coupling and the dome; a plurality of skirts, each skirt covering a gap formed between adjacent legs and each skirt mounted to edges of adjacent legs; a plurality of roller cones, each rotary cone rotatably mounted to a respective bearing shaft of a respective leg; a row of gage cutters mounted to each roller cone; a row of inner cutters mounted to each roller cone; one or more nose cutters mounted to each roller cone; and a center jet secured in the bore. Each cutter is an insert.

A rock bit for blast hole drilling includes: a bit body having a coupling formed at an upper end thereof, a plurality of lower legs, a dome formed between the legs, and a bore formed through the coupling and the dome; a plurality of skirts, each skirt covering a gap formed between adjacent legs and each skirt mounted to edges of adjacent legs; a plurality of roller cones, each rotary cone rotatably mounted to a respective bearing shaft of a respective leg; a row of gage cutters mounted to each roller cone; a row of inner cutters mounted to each roller cone; one or more nose cutters mounted to each roller cone; and a center jet secured in the bore. Each cutter is an insert.