Abstract: During operation of a gas turbine engine, the airfoils of turbine blades are exposed to very high temperatures. Embodiments of a turbine blade may comprise an outer cooling channel, which supplies coolant to the leading edge and tip of the airfoil, and wraps around inner cooling channel(s), which supply coolant to the middle of the airfoil. These outer and inner cooling channels may merge in a merge channel with an aft cooling channel that supplies coolant to the trailing edge and tip of the airfoil. In an embodiment, discrete pressure-side and suction-side inner cooling channels may provide a flow path for coolant in opposing directions to thereby reduce temperature gradients within the airfoil. Embodiments may also comprise other cooling features, including cooling holes, trip strips, and/or pins.

Abstract: In a gas turbine engine, turbine blades are subjected to extremely high gas temperatures and mechanical stresses. Disclosed embodiments utilize one or more cooling and/or stress-reduction features. For example, flared and/or shaped cooling apertures may be provided through a platform, adjacent to a leading edge of a fillet of the airfoil of the turbine blade, and/or through the leading edge of the fillet. As another example, an aperture may provide coolant from an under-platform cavity to a trailing edge of the fillet. As another example, a tip flag may be provided in the interior of the airfoil, with trip strips to turbulate the flow of coolant through the tip flag and a reduced spar height to reduce stress. As another example, the aft axial end of a pin seal slot may axially extend beyond the fillet, in the aft direction, to reduce stiffness and produce beneficial transient behavior.

Abstract: During operation of a gas turbine engine, the turbine blades are subjected to extremely high temperatures. While internal cooling passages may be provided within the turbine blades to cool the airfoils, the platforms of the turbine blades also experience high temperatures. In an embodiment, cooling holes are provided in each platform to cool distressed locations in the platform and improve the durability of each turbine blade.

Abstract: During operation of a gas turbine engine, the turbine blades are subjected to extremely high temperatures. While internal cooling passages may be provided within the turbine blades to cool the airfoils, the platforms of the turbine blades also experience high temperatures. In an embodiment, cooling holes are provided in each platform to cool distressed locations in the platform and improve the durability of each turbine blade.

Abstract: A method of forming a cutting element comprises forming a first material comprising discrete coated particles within a container. The first material is pressed to form a first green structure comprising interbonded coated particles. A second material comprising additional discrete coated particles is formed over the first green structure within the container. The second material is pressed to form a second green structure comprising additional interbonded coated particles. The first green structure and the second green structure are sintered to form a multi-layered cutting table. Additional methods of forming a cutting element, a cutting element, and an earth-boring tool are also described.

Abstract: Methods of evaluating prototype cutting elements for earth-boring tools may involve generating first and second sets of virtual representations of cutting elements from first and second sets of used cutting elements. First and second sets of measures of damage corresponding to damage for each of the first and second sets set of virtual representations of cutting elements may be determined. A best-performing set of cutting elements from the first and second sets of used cutting elements according to the first and second sets of measures of damage may be identified by performing a statistical analysis.

Abstract: Methods of forming a volume of hard material on a component of a downhole tool include depositing a film of amorphous carbon on a substrate, irradiating the film of amorphous carbon to form a liquid carbon in an undercooled state, and quenching the liquid carbon to form a layer of quenched carbon on the substrate. A downhole tool comprises a component and a volume of hard material comprising quenched carbon disposed on a surface of the component. Additional downhole tools comprise a component and a polycrystalline compact comprising quenched carbon grains disposed on a surface of the component.

Abstract: A method of forming a cutting element comprises forming a first material comprising discrete coated particles within a container. The first material is pressed to form a first green structure comprising interbonded coated particles. A second material comprising additional discrete coated particles is formed over the first green structure within the container. The second material is pressed to form a second green structure comprising additional interbonded coated particles. The first green structure and the second green structure are sintered to form a multi-layered cutting table. Additional methods of forming a cutting element, a cutting element, and an earth-boring tool are also described.

Abstract: Methods of evaluating prototype cutting elements for earth-boring tools may involve generating first and second sets of virtual representations of cutting elements from first and second sets of used cutting elements. First and second sets of measures of damage corresponding to damage for each of the first and second sets set of virtual representations of cutting elements may be determined. A best-performing set of cutting elements from the first and second sets of used cutting elements according to the first and second sets of measures of damage may be identified by performing a statistical analysis.

Abstract: In one aspect, a drill bit is disclosed that in one embodiment may include a bit body, a rotating cutter on the bit body, and a metallic seal between the bit body and the rotating cutter that includes a first seal member, a second seal member having a first end in sealing contact with the first seal member, a second end fixed relative to the first end and a bias member between the first end and the second end that adjusts the load on the first seal member in response to external load applied on the drill bit.

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: In one aspect, a drill bit is disclosed that in one embodiment may include a bit body, a rotating cutter on the bit body, and a metallic seal between the bit body and the rotating cutter that includes a first seal member, a second seal member having a first end in sealing contact with the first seal member, a second end fixed relative to the first end and a bias member between the first end and the second end that adjusts the load on the first seal member in response to external load applied on the drill bit.

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: 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: In an aspect, a drilling motor is provided that in one embodiment includes a stator and a rotor configured to be disposed in the stator, wherein the rotor includes a lobe member having an elastically deformable surface configured to provide an interference seal between the stator and the rotor.

Abstract: In an aspect, a drilling motor is provided that in one embodiment includes a stator and a rotor configured to be disposed in the stator, wherein the rotor includes a lobe member having an elastically deformable surface configured to provide an interference seal between the stator and the rotor.

Abstract: A roller cone bit is provided that includes a wear resistant coating applied to a bearing shaft, which is attached to a roller cone. The wear resistant coating can be a tungsten/tungsten carbide composite applied by chemical vapor deposition.

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: A rock drilling bit having PDC radial bearings has journal and cone bearing surfaces with increased contact area to increase load support. The radius of curvature of the bearing pin journal and cone bearing surfaces are matched or conformed on the bearing pressure side. The conformal journal surfaces may be formed on the main journal bearing, the pilot pin radial bearing, or both surfaces. In addition, diamond inlays may be located on the bearing surfaces of the cone, the bearing pin, or both components.

Abstract: A rotatable cone earth boring bit has a bearing system with at least on the surfaces being AlMgB14 alloy material. The alloy material also contains an alloying agent, which may be titanium boride (TiB2); titanium carbide (TiC) plus iron, nickel and carbon; silicon nitride (Si3N4) powder; whiskered silicon nitride (Si3N4); boron carbide (B4C); titanium boride (TiB2); or tungsten boride (W2B4). The surface containing the AlMgB14 alloy material may be a journal surface or thrust face on the bearing pin. The surface containing the AlMgB14 alloy material may also be a seal surface, either on a metal face seal or a gland on the bearing pin engaged by an elastomeric ring. The AlMgB14 alloy material may a coating or it may be a free-standing structural member within the bearing system.