Abstract: A hardened bearing surface (36, 38, 42, 48, 50, 51 and 52) on a component (14, 16) of a rotary cutter drill bit (10) and the method of forming same. A composite mix (60) of alloy material (56) and base material (54) forms the hardened bearing surface (36, 38, 42, 48, 50, 51 and 52) with the alloy material (56) consisting of at least ten (10) percent of the adjacent base material (54) and of an optimum of around fifty (50) percent. The alloy material (56) of predetermined amounts of predetermined elements is positioned on the base material (54) and a precisely controlled high energy density source, such as a laser beam (58), melts the alloy material (56) and adjacent base material (56) to form the composite mix (60) defining the hardened bearing surface.

Abstract: A rolling cutter drill bit is disclosed having an improved thrust face bearing structure which utilizes alternating segments of at least two different bearing metals. The composite thrust face bearing structure disclosed has a first metal selected for a low temperature operation, and at least one additional metal selected for high temperature operation.

Abstract: A rolling cutter drill bit is disclosed which utilizes a plurality of rolling cutters each rotatably mounted on a lug member having a downwardly extending bearing journal. Each bearing journal has a ball bearing race formed therein for receiving a series of ball bearings which also seat in a mating ball bearing race formed in the rotatably mounted cutter. The ball bearings are arranged to share the axial loading placed on the rolling cutter and primarily lock the cutter on the journal shaft. Each journal is further provided with a unique large thrust surface across the downward end of the bearing shaft and generally perpendicular to the radial bearing surface. The large flat perpendicular thrust surface eliminates the need for a standard pilot pin structure normally found in rolling cutter bits.