A rolling cone earth boring bit has a diverter and an arcuate segment located between the bit leg and the back face of the cone to divert debris from the seal gland area. The diverter has an oblong or oval base that inserts into a mating hole in a last machined surface of the bit. The diverter has a head that is wedge-shaped and protrudes from the hole into a clearance between the back face and the last machined surface. The head has an inner side that is spaced from an annular wall of the back ...

A rolling cone earth boring bit has a diverter located between the bit leg and the back face of the cone to divert debris from the seal gland area. The diverter has a base that inserts into a hole in a last machined surface of the bit. The diverter has a head that is wedge-shaped and protrudes from the hole into a clearance between the back face and the last machined surface. The head has an inner side that is spaced from an annular wall of the back face by a small uniform clearance. The head ha...

An earth boring bit has a seal cavity that is eccentric to agitate drilling fluid and avoid mud packing. The bit body having bit legs, each having a bearing pin. A cone rotatably mounts on the bearing pin. Teeth are formed or mounted on the cone for cutting the earth formation as the bit rotates. The cone has a backface adjacent the bit leg and an entrance portion to the cavity that intersects the backface. A seal assembly is in stationary engagement with the bearing pin and sliding engagement w...

An earth-boring bit has a mechanical face seal assembly with PCD faces. The bit has a bearing shaft with a cone rotatably mounted on the bearing shaft. The seal locates between the bearing shaft and the cone for sealing lubricant therein. The seal includes at least one rigid seal ring having a cemented carbide body and an annular PCD face located on it. The mating face may also be of a PCD material. The cemented carbide body contains a binder that migrates into the PCD face while the PCD face is...

An earth-boring bit has a bit body and at least one bearing shaft depending inwardly and downwardly from the bit body. The bearing shaft has a base and a generally cylindrical bearing surface and at least one cutter is mounted for rotation on the bearing shaft. A bearing seal recess is formed generally at the base of the bearing shaft and defines a cylindrical seal face radially recessed from the journal bearing surface. A cutter seal recess is formed in the cutter generally opposite the bearing...

A rotary cone drill bit for forming a borehole having a bit body with an upper end portion adapted for connection to a drill string. A number of angularly-spaced support arms formed to extend from the bit body. Each support arm has an inside surface with a spindle connected thereto and an outer shirttail surface. A number of cutter cones equal to the number of support arms are rotatably mounted on respective spindles. Each of the cutter cones includes an internal cylindrical cavity for receiving...

A mechanical seal for use in a rotary rock bit comprises a leg seal ring positioned within a recessed portion of a leg forming a seal cavity. The leg seal comprises one surface partially engaged by a resilient material and an opposite surface comprising a first sealing surface. The mechanical seal also comprises cone seal ring positioned within a portion of a cone forming the seal cavity. The cone seal comprises one surface positioned within and attached to a recessed portion of the cone and ano...

An improved journal bearing for rotary cone type mining or oilfield rock bits is disclosed. Such rock bits typically have several cutters each rotatably mounted on a cantilevered bearing pin. The cutter and respective bearing have complementary journal bearing surfaces. A retainer is provided at one end at the bearing surfaces for keeping the cutter on the bearing pin and a seal is provided at the opposite end. In addition to the usual axial thrust surface located towards the radially inner end ...

An earth boring drill employing roller cutters is provided with a seal in a peripheral groove to inhibit ingress of detritus into the cutter bearing area and egress of lubricant therefrom. The shape of the seal is such that its cross section is not overly compressed or displaced when in operating position, thus preventing undue compression set, wear and heating of the seal. A preferred seal has a greater radial dimension than axial dimension by a ratio of at least one-and-one-half to one to cons...

A rock drill bit includes at least one leg about which a roller cutter is rotatably mounted. A ring-shaped seal is disposed between an end surface of the leg and a sealing surface of the roller cutter. The seal is arranged coaxially with respect to an axis of rotation of the roller cutter and is formed of an elastic material and a relatively rigid material embedded within the elastic material. The elastic material defines first and second surfaces which engage the leg and the roller cutter, resp...