Patent ID: 6354740
Filing Date: 2002-03-12
Classification: E21B,F16C,Y10S

Abstract:
Rolling cutter drill bit comprising a body and a plurality of legs, at least one of said legs having a cantilevered bearing spindle, a rolling cutter rotatably mounted on the bearing spindle, lubricant delivering means within the bearing spindle, and a floating thrust bearing element configured to carry onward thrust loads from the rolling cutter onto said bearing spindle, said floating thrust bearing element being formed of a wrought alloy material consisting primarily of chromium carbide and cobalt and having a yield strength of less than 120,000 psi and a ductility of at least 4%, both at room temperature, wherein said floating thrust bearing element has load carrying surfaces at least one of which is coated with one or more layers of soft metallic solid lubricant material.