Finite Element Simulation as a Tool to Evaluate Gear Quality after Gear Rolling

Gear rolling is a manufacturing technique for gears with many advantages like reduced material consumption, reduced scrap generation, fast cycle times, good surface quality and improved final properties of the gear wheels compared to conventional production technology based on machining. In order to make use of all these advantages it is desired to reach the final shape of the gear wheel already after rolling. This means that post treatments like grinding should be avoided. This puts high requirements on the shape accuracy after gear rolling. In this paper it was studied if finite element simulation could be used to evaluate the shape accuracy after gear rolling. The measurement of shape accuracy of gear wheels is specified in standards like ISO1328-1. The allowed deviations from nominal shape are often of the order of 10-30 μm for very good qualities. So if such evaluation shall be possible from a finite element simulation the accuracy must be of the same order. In order to have sufficient accuracy of the finite element simulation 2D simulations were performed on a spur gear. The FE code DEFORM was utilized. The shape accuracy was evaluated for gear rolling of two cases. One case had gears with the module of 1 mm. The other case involved gears with a significantly larger module of 4 mm. This was an interesting case since it is known that it is more difficult to roll the gear with good accuracy in large modules.