US Patent 8172716 Epicyclic gear system with superfinished journal bearing

An epicyclic gear assembly includes a ring gear, a sun gear, at least one star gear enmeshed between the ring gear and sun gear, a carrier and a journal bearing. The carrier is disposed adjacent the rotatable sun gear and star gear. The journal bearing is disposed in the at least one star gear and connected to the carrier. The journal bearing has an outer radial surface with an amorphous surface finish of less than about 5 micro inches (127 micro mm) measured on an Ra scale and the outer surface of the journal bearing interfaces with an inner surface of the star gear.