Forming processes are generally characterized by a high degree of material utilization as well as short process times and, consequently, a decent economic efficiency. Furthermore, incremental forming enables the use of relatively low forming forces which results in a more compact design of the used machines. These conveniences are utilized in terms of roll forming with round tools to form gears and threads in a competitive way. Based on experiences gained over many years of researching rolling technologies, a cross-rolling process characterized by round tools with outer gearings was elaborated to realize a hot forming process of large gears at the Fraunhofer IWU. At actual project GEARFORM, a scaled sun gear demonstrator from wind gear application could be realized by hot rolling technology. An optimized rolling time was achieved by 32.5 seconds.
Neugebauer, R. and Hellfritzsch, U. (2007) Improved Process Design and Quality for Gear Manufacturing with Flat and Round Rolling. International Institution for Production Engineering Research CIRP, 57th General Assembly of CIRP, Dresden, 307-312.