Abstract: Self relieving seals of this invention comprise an elastomeric seal body having a first sealing surface and a second sealing surface for contact with respective drill bit sealing surfaces. The seal includes a pair of external surfaces that each extend along the seal body between the first and second sealing surfaces. The seal includes one or more relief ports that are disposed through the seal body and that have openings through each of the seal body external surfaces. The relief port can be specially configured, e.g., have different diameter sections of constant or variable dimensions, to provide a degree of control over pressure equalization through the seal body when the seal is loaded within the drill bit. The seal may include an element, e.g., solid, tubular, or porous, disposed within the relief port to provide a further desired degree of control over pressure equalization through the seal when the seal is loaded within the drill bit.

Abstract: Self relieving seals of this invention comprise an elastomeric seal body having a first sealing surface and a second sealing surface for contact with respective drill bit sealing surfaces. The seal includes a pair of external surfaces that each extend along the seal body between the first and second sealing surfaces. The seal includes one or more relief ports that are disposed through the seal body and that have openings through each of the seal body external surfaces. The relief port can be specially configured, e.g., have different diameter sections of constant or variable dimensions, to provide a degree of control over pressure equalization through the seal body when the seal is loaded within the drill bit. The seal may include an element, e.g., solid, tubular, or porous, disposed within the relief port to provide a further desired degree of control over pressure equalization through the seal when the seal is loaded within the drill bit.

Abstract: Self relieving seals of this invention comprise an elastomeric seal body having a first sealing surface and a second sealing surface for contact with respective drill bit sealing surfaces. The seal includes a pair of external surfaces that each extend along the seal body between the first and second sealing surfaces. The seal includes one or more relief ports that are disposed through the seal body and that have openings through each of the seal body external surfaces. The relief port can be specially configured, e.g., have different diameter sections of constant or variable dimensions, to provide a degree of control over pressure equalization through the seal body when the seal is loaded within the drill bit. The seal may include an element, e.g., solid, tubular, or porous, disposed within the relief port to provide a further desired degree of control over pressure equalization through the seal when the seal is loaded within the drill bit.

Abstract: Self relieving seals of this invention comprise an elastomeric seal body having a first sealing surface and a second sealing surface for contact with respective drill bit sealing surfaces. The seal includes a pair of external surfaces that each extend along the seal body between the first and second sealing surfaces. The seal includes one or more relief ports that are disposed through the seal body and that have openings through each of the seal body external surfaces. The relief port can be specially configured, e.g., have different diameter sections of constant or variable dimensions, to provide a degree of control over pressure equalization through the seal body when the seal is loaded within the drill bit. The seal may include an element, e.g., solid, tubular, or porous, disposed within the relief port to provide a further desired degree of control over pressure equalization through the seal when the seal is loaded within the drill bit.

Abstract: The invention is a roller cone drill bit including a seal adapted to seal between the bit body and a roller cone on the drill bit. The seal includes a seal body formed from a material that is adapted to energize the seal after compression of the seal. A first dynamic seal surface formed on the seal body and is adapted to seal against the bit body. A second dynamic seal surface is formed the seal body and is adapted to seal against the roller cone. The first and second dynamic seal surfaces are formed from a material adapted to withstand relative motion between the first dynamic seal surface and the bit body and between the second dynamic seal surface and the roller cone.

Abstract: The invention is a roller cone drill bit including a seal adapted to seal between the bit body and a roller cone on the drill bit. The seal includes a seal body formed from a material that is adapted to energize the seal after compression of the seal. A first dynamic seal surface formed on the seal body and is adapted to seal against the bit body. A second dynamic seal surface is formed the seal body and is adapted to seal against the roller cone. The first and second dynamic seal surfaces are formed from a material adapted to withstand relative motion between the first dynamic seal surface and the bit body and between the second dynamic seal surface and the roller cone.

Abstract: O-ring seals for rock bit bearings comprise a body formed from an elastomeric material having one or more lubricant additive uniformly distributed throughout to reduce the coefficient of friction and stick slick amplitude at O-ring seal surfaces. The lubricant additives are selected from the group consisting of polytetrafluoroethylene, hexagonal boron nitride, flake graphite, ultra-high molecular weight polyurethane, and mixtures thereof. O-ring seals made from elastomeric compositions of this invention comprise in the range of from about 85 to 99 percent by volume elastomeric material, and in the range of from about 1 to 15 percent by volume of the lubricant additives based on the total volume of the composition.

Abstract: A drill bit having a canted or non-canted leg backface, a canted or non-canted seal in the interface between the cone backface and the shirttail, and a canted seal that can be semi-encapsulated so that there is no straight-line path across the seal.

Abstract: A nutation motion generator which transforms linear motion into nutation motion. The device employs a spherical, four-bar linkage mechanism. Three four-bar linkage mechanisms are sandwiched between a stationary support surface and a drive plate and arranged at 120.degree. intervals about the support surface. Each four-bar linkage mechanism is constructed of four planar sections which are hinged along their edges, the four hinged planar sections being essentially triangular in shape so that they would join at a point in the center of the device if they extended to the apex of their respective triangles. A universal joint is located at the center of the device to provide stability. The four-bar linkage mechanism can be collapsed to a substantially flatten configuration, opened and then collapsed to a substantially flattened configuration at an angle 90.degree. to that of the first flattened configuration.

Abstract: An improved O-ring seal for rock bit bearings comprises a body formed from a resilient elastomeric composition and a modified surface comprising a surface enhancing material integral with the body. The surface comprises a layer of surface enhancing material that encapsulates and is molecularly bonded to an underlying surface of an elastomeric seal body. The surface enhancing material selected may include metal disulfides, fluoropolymers, ethylene polymers, silicone polymers, and urethane polymers. The O-ring surface displays enhanced properties of reduced break-off friction, increased lubricity and wettablity, and increased thermal resistance. These enhanced surface properties serve to minimize stick-slip and material loss from the O-ring surface resulting from stick-slip, thereby increasing the service life of the O-ring seal and rock bit.