PREVENTION OF CONE SEAL FAILURES IN ROCK BITS

摘要

There is provided a rock bit comprising a bit body having a dome and a plurality of legs, each with a journal pin. A cutter cone is mounted on each journal pin with a cone seal between the journal pin and cutter cone. A sacrificial anode is attached to the dome of the bit body having a shape for diverting flow of drilling mud around the cutter cones. Preferred shapes of the sacrificial anode include inverted cones and tetrahedrons. The sacrificial anode prevents cone seal failures caused by corrosion of the bit body adjacent the cone seals.