Dresser Industries, Inc.

Wilbur S Keller

James W Langford, Jr

William D Vanderford

Lubricant is circulated from a lubricant reservoir to the bearings of a rotary rock bit and back to the lubricant reservoir by a lubricant circulation system that is operated by rotation of the cone cutter upon the bearing pin of the bit. A seal is positioned between the rolling cone cutter and the arm of the bit to maintain lubricant in the bearing area and to prevent fluid in the borehole from entering the bearing area. A lubricant reservoir is located in the bit body. A first passage connects the lubricant reservoir with the bearing area to channel lubricant from the lubricant reservoir to the bearing area. A second passage extends from the bearing area to the lubricant reservoir to allow lubricant to be channeled back to the lubricant reservoir. A groove system in the thrust flange of the cone cutter operates as a viscous or ram pump when rotating against the thrust flange of the bearing pin thereby providing a pumping action to circulate lubricant from the lubricant reservoir through said first passage to the bearing area and from the bearing area through said second passage back to said lubricant reservoir.

Thrust flange actuated rock bit lubrication system

A rolling cone earth boring bit is produced having a bearing surface that has been infiltrated to a controlled depth. A groove is machined in one of the bearing members. The bearing member is placed in a die and an alloy powder material is pressed into the groove recess thereby producing a porous matrix for the bearing element. The bearing element is sintered to provide a porosity within the range of 10% to 20%. An anti-galling material is infiltrated into said porous matrix bearing element. The porous matrix bearing element is hardened resulting in a high-strength bearing that will provide performance with high loads at low RPM or high RPM.

Method of manufacturing a rotary rock bit

An asymmetric insert has a formation contacting crest thereby decreasing the loading on the insert and increasing the lifetime of the cutter. The insert has a shape prior to assembly in the cutter that includes a base integrally joined to an asymmetric head. The base is mounted in a socket in the cutter body. The head projects from the surface of the cutter and includes a crest positioned to contact the formations with substantially its entire length.

Asymmetric insert for inner row of an earth boring cutter

An asymmetric gage row insert provides a larger amount of wall contacting surface thereby decreasing the wear on the gage insert and increasing the ability of the earth boring apparatus to maintain a full gage hole. The insert has a shape prior to assembly onto the earth boring apparatus that includes a base integrally joined to an asymmetric head. The base is mounted in a socket in the earth boring apparatus. The head projects from the earth boring apparatus and includes an extended gage cutting surface. The gage cutting surface is the largest plane surface on the head. The gage cutting surface contacts the wall of the hole with the majority of the length of its extended surface and with the same angle as the gage angle of the bit.

Asymmetric gage insert for an earth boring apparatus

Galling in the ball bearing raceway of a rotary rock bit is reduced even when the thrust bearings of the rock bit have worn to the point that the ball bearings are loaded by out thrust. The radius of the ball bearing raceway in the bearing pin and/or the cutter includes an inlay of anti-galling material. The anti-galling material insures that any material worn from the raceway will not harm the other bearing elements.

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Arlington, TX, United States of America

Wilbur S Keller