Rolling processes for gear manufacturing-potentials and challenges

Due to the increasing demands concerning resource-efficient manufacturing processes, the aspect of material savings becomes more and more important. In comparison with cutting operations, the use of forming processes offers the chance to achieve significant saving effects. In the field of the automotive powertrain, the manufacturing of helical gears by rolling processes is an outstanding example. By contrast with machining processes, the following benefits can be identified: - no chip generation, therefore no material loss, - reduced process time (up to 50%), - higher surface qualities, - improved load capacity based on contour-related, uninterrupted fibre orientation, - reduced distortion by forming-related generation of residual stresses, - based on extensive investigations in the last years, helical gears with tooth heights higher than 12 mm and with a gearing quality of 9 have been realized.