Gear rolling technology: Presentation held at Gear Meeting 2010, 13.10.-15.10.2010, Köping, Sweden

New transmission developments and the related component manufacturing focus on cost and efficiency optimisation of current manufacturing processes while ensuring the required part quality and performance characteristics. Forming processes offer particularly high optimisation potential compared to the actual gear fabrication processes. Especially the gear cold rolling of typical case hardening and heat-treated steels has significant advantageous characteristics compared to conventional cutting processes of pre-gearing (e.g. gear hobbing). Based on the finished gear, material savings up to 30% depending on the gear geometry can be achieved. Other advantages of forming involute tooth profiles by cold rolling are extremely short process times, no material loss, elimination of waste removal, contour related and refined grain structure and minimal thermal distortion after heat treatment processes. 40% strain hardening of the gear flank zone, 80% of the tooth root area compared to basic hardness as well as high achievable surface roughnesses of Ra = 0.4 mm/ Rz = 1.5 mm are advantageous for applications without subsequent heat treatment. The latest investigations in process simulation allow a review of the load optimised tool and process design. The process simulation reduces cost and time-consuming optimisation loops. The increasingly demand for short manufacturing processes with optimal use of raw materials that ensure the quality of final products, will increase the application of gear forming technologies in the future