Abstract: A downhole sensor apparatus including a structure and an electronics package. The structure and the electronics package configured to be inserted into a recess in an earth-boring tool on a drill string. The downhole sensor apparatus may include a cradle extending away from a first surface of the structure. The cradle is configured to at least partially receive a battery therein. The downhole sensor apparatus includes a cap configured to engage with the earth-boring tool and secure the structure within the recess. The downhole sensor apparatus also may include a ring disposed between the structure and the cap. The ring is configured to transfer a force from the cap to the structure, forcing a second surface of the structure against a bottom surface of the recess. An earth-boring tool comprising a recess in the earth-boring tool configured to receive a downhole sensor apparatus. A method securing a downhole sensor apparatus to an earth-boring tool.

Abstract: A rotatable cutting element includes a stationary portion defining a cavity with an inner wall, the inner wall extending at an angle radially away from a longitudinal axis of the stationary portion and defining a retaining region. The rotatable cutting element further includes a rotatable portion having one end thereof disposed in the cavity of the stationary portion and structure for engaging a subterranean formation at an opposing end. The rotatable cutting element also includes a retaining element extending between the rotatable portion and the stationary portion, the retaining element extending into the retaining region defined by the inner wall of the stationary portion.

Abstract: An earth-boring rotary drill tool may comprise a body comprising a pin, a roller cone mounted on the pin, and a seal assembly disposed between the pin and the roller cone. The first ring may comprise longitudinally converging sidewall surfaces defining a minimum radial thickness of the first ring at points of tangential intersection with a convex curved surface spanning a radial thickness of the first ring. The second ring may comprise a concave surface located and configured to interface over an area of contact with the convex curved surface of the first ring. The third ring may be positioned adjacent to, and concentric with, the second ring. The second ring may be disposed radially inward from the third ring. The first ring may also contact a surface of the roller cone or an insert ring adjacent the roller cone to form a seal between the first ring and the surface.

Abstract: An earth-boring rotary drill tool may comprise a body comprising a pin, a roller cone mounted on the pin, and a seal assembly disposed between the pin and the roller cone. The first ring may comprise longitudinally converging sidewall surfaces defining a minimum radial thickness of the first ring at points of tangential intersection with a convex curved surface spanning a radial thickness of the first ring. The second ring may comprise a concave surface located and configured to interface over an area of contact with the convex curved surface of the first ring. The third ring may be positioned adjacent to, and concentric with, the second ring. The second ring may be disposed radially inward from the third ring. The first ring may also contact a surface of the roller cone or an insert ring adjacent the roller cone to form a seal between the first ring and the surface.

Abstract: A rotatable cutting element includes a stationary portion defining a cavity with an inner wall, the inner wall extending at an angle radially away from a longitudinal axis of the stationary portion and defining a retaining region. The rotatable cutting element further includes a rotatable portion having one end thereof disposed in the cavity of the stationary portion and structure for engaging a subterranean formation at an opposing end. The rotatable cutting element also includes a retaining element extending between the rotatable portion and the stationary portion, the retaining element extending into the retaining region defined by the inner wall of the stationary portion.

Abstract: A cutting element assembly includes a cutting element and a sleeve having a cutter-receiving aperture configured to receive at least a portion of the cutting element within the cutter-receiving aperture. The cutting element assembly may also include a retention element rotatably coupling the cutting element to the sleeve and a biasing member disposed between the cutting element and the sleeve. The biasing member may be configured to bias the cutting element relative to the sleeve. A method of forming a downhole tool includes forming a bit body including at least one blade, securing at least one sleeve to the blade, disposing at least one biasing member within the cutter-receiving aperture, and inserting a cutting element into the cutter-receiving aperture of the at least one sleeve, such that the at least one biasing member is disposed between the at least one sleeve and the cutting element.

Abstract: A cutting element assembly includes a cutting element and a sleeve having a cutter-receiving aperture configured to receive at least a portion of the cutting element within the cutter-receiving aperture. The cutting element assembly may also include a retention element rotatably coupling the cutting element to the sleeve and a biasing member disposed between the cutting element and the sleeve. The biasing member may be configured to bias the cutting element relative to the sleeve. A method of forming a downhole tool includes forming a bit body including at least one blade, securing at least one sleeve to the blade, disposing at least one biasing member within the cutter-receiving aperture, and inserting a cutting element into the cutter-receiving aperture of the at least one sleeve, such that the at least one biasing member is disposed between the at least one sleeve and the cutting element.

Abstract: Rotatable elements for use with earth-boring tools include a movable element and a stationary element. The rotatable element may include a void within the support structure and at least one pin protruding from the void through an exterior side of the support structure. The rotatable element may further include at least one aperture configured to provide a vent to the void. The rotatable element may be disposed at least partially within a cavity of the stationary element. The stationary element may further include a track configured to interact with the at least one pin.

Abstract: A rotatable element for an earth-boring tool in a subterranean borehole includes a rotatable element and a stationary element. The rotatable element and stationary element include a seal arrangement between the rotatable element and the stationary element. The seal arrangement encloses a volume that remains substantially constant as the rotatable element moves relative to the stationary element.

Abstract: Hardfacing materials include a polymer matrix material and particles of hard material embedded within and dispersed throughout the polymer matrix material. Earth-boring tools include a tool body and a hardfacing material on at least a portion of a surface of the body, wherein the hardfacing material includes a polymer matrix material and particles of hard material embedded within and dispersed throughout the polymer matrix material. Methods of applying hardfacing material to an earth-boring tool comprise mixing hard particles with a polymer precursor material to form a paste, applying the paste to a surface of an earth-boring tool, and curing the polymer precursor material to form a hardfacing material on the surface of the earth-boring tool.

Abstract: A rotatable cutter may comprise a rotatable element, a stationary element, and a releasable interface. The releasable interface may be configured to substantially inhibit rotation of the rotatable element when the rotatable element and the stationary element are at least in partial contact. An earth-boring tool may include one or more rotatable elements.

Abstract: A cutting element assembly includes a sleeve having a cutter-receiving aperture extending through the sleeve, a cutting element, and a rotation restriction element. The cutting element may include a first plurality of retention elements extending substantially radially from an outer surface of the cutting element and engaging the sleeve to retain the cutting element within the sleeve. The rotation restriction element may be coupled to the cutting element and may include a second plurality of retention elements extending axially from a bottom surface of the rotation restriction element and engaging the sleeve to restrict rotation of the cutting element within the sleeve.

Abstract: Rotatable elements for use with earth-boring tools include a movable element and a stationary element. The movable element and stationary element include an index positioning feature that is configured to rotate the movable element as the movable element moves between a first axial position and a second axial position.

Abstract: Rotatable elements for use with earth-boring tools include a movable element and a stationary element. The rotatable element may include a void within the support structure and at least one pin protruding from the void through an exterior side of the support structure. The rotatable element may further include at least one aperture configured to provide a vent to the void. The rotatable element may be disposed at least partially within a cavity of the stationary element. The stationary element may further include a track configured to interact with the at least one pin.

Abstract: An earth-boring drill bit includes a bit body including a central shaft having a longitudinal axis, an annular cutter body disposed around, and rotatable relative to, the central shaft, at least one gear assembly operatively coupling the annular cutter body to the central shaft, a first cutter disposed on the central shaft at a first distance from the longitudinal axis, and a second cutter disposed on the annular cutter body at a second, greater distance from the longitudinal axis. Methods of fabricating earth-boring drill bits include rotatably coupling at least one annular cutter body to a central shaft, the at least one annular cutter body and the central shaft being concentric.

Abstract: Methods of forming a stationary housing of a rotatable cutting element for use on an earth-boring tool may include forming one or more annular recesses extending around an outer surface of a first sleeve, inserting the first sleeve within a second sleeve, joining the first sleeve with the second sleeve, and removing a portion of material from an inner surface of the first sleeve to expose the annular recesses. Methods may also include forming a first portion and a second portion of a sleeve, forming an annular recess around an entire perimeter of an inner surface of each of the first portion and the second portion of the sleeve proximate a longitudinal end thereof, and bonding the longitudinal ends of the first portion and the second portion of the sleeve along an interface therebetween. Stationary housings formed from such methods are also provided.

Abstract: Bearing systems configured for use on a downhole tool may include a tensioner bolt having a complementary nut, the tensioner bolt and nut sized and shaped to secure the rolling cutter member to a head. A radial bearing may include an annular sleeve sized and shaped to surround the head. A shaft washer may be sized and shaped to surround the head between an enlarged head of the tensioner bolt and the annular sleeve. A bearing element may be configured for positioning proximate the head, the bearing element comprising an upper surface configured for sliding, frictional contact with a lower surface of the shaft washer.

Abstract: A cutting element assembly includes a rotatable cutting element, a sleeve having a cutter receiving aperture extending at least partially through the sleeve and configured to receive at least a portion of the rotatable cutting element within the cutter-receiving aperture, and a retention element rotatably coupling the rotatable cutting element to the sleeve. In some embodiments, the retention element includes a pin extending from a base portion of the sleeve and having at least one resilient portion having at least one protrusion radially extending outward. In additional embodiments, the retention element include a split ring or O-ring disposed within a groove of the rotatable cutting element. Earth-boring tools having rotating cutting elements are also disclosed.

Abstract: A cutting element assembly may include a support structure and a pin having a cylindrical exterior bearing surface. Retention elements may couple opposing ends of the pin to the support structure. The cutting element assembly also includes a rotatable cutting element including a table of polycrystalline hard material having an end cutting surface and a supporting substrate. The rotatable cutting element may have an interior sidewall defining a longitudinally extending through hole. The pin may be positioned within the through hole of the rotatable cutting element and may be supported on the opposing ends thereof by the support structure. Methods include drilling a subterranean formation including engaging a formation with one or more of the rotatable cutting elements.

Abstract: A cutting element assembly includes a sleeve, a rotatable cutting element disposed within the sleeve, and a retention element. The sleeve and rotatable cutting element each have frustoconical surfaces. In some embodiments, a rotatable cutting element defines a first generally cylindrical surface, a second generally cylindrical surface, and an axial bearing surface opposite the end cutting surface and intersecting each of the first generally cylindrical surface and the second generally cylindrical surface. A bearing element may be disposed between an upper surface of a sleeve and a bearing surface of the rotatable cutting element. Earth-boring tools having rotating cutting elements are also disclosed.