Abstract: A method of forming a ring gear from a ring blank includes providing a mandrel having a central axis and an outer annular forming surface. The outer annular forming surface defines a plurality of forming elements having a forming element axis offset from the central axis of the mandrel. The ring blank has a ring axis and is placed over the mandrel generally aligning the central axis of the mandrel with the ring axis of the ring blank. A roll is provided having a roll axis that is generally parallel with the element axis. The roll is forced radially inwardly while circumscribing the central axis. The roll pivots around the roll axis deforming the ring blank radially inwardly forming teeth on an inner surface of the ring blank that coaxial with the element axis and offset from the mandrel axis.

Abstract: A method of forming a ring gear from a ring blank includes providing a mandrel having a central axis and an outer annular forming surface. The outer annular forming surface defines a plurality of forming elements having a forming element axis offset from the central axis of the mandrel. The ring blank has a ring axis and is placed over the mandrel generally aligning the central axis of the mandrel with the ring axis of the ring blank. A roll is provided having a roll axis that is generally parallel with the element axis. The roll is forced radially inwardly while circumscribing the central axis. The roll pivots around the roll axis deforming the ring blank radially inwardly forming teeth on an inner surface of the ring blank that coaxial with the element axis and offset from the mandrel axis.