Forging and heading of hollow spur gear forms: an analysis and some experiments

To analyse the process of incremental forging and heading of hollow spur gear forms from initially ring-type specimens, the two types of theoretical approaches followed were an adaptation of the upper bound technique, applied previously to the solution of solid spur gear form forging (Chitkara NR, Bhutta MA. International Journal of Mechanical Sciences 1996;38(8–9):891–916) and the modification of the slab method of analysis given earlier for the case of spline forging and adapting it to the tapered teeth representing the actual profile teeth of the spur gear with the pressure angle of 14°, (Chitkara NR, Bhutta MA. International Journal of Mechanical Sciences 1996;38(8–9):871–89). In each case, the theoretical results estimated were compared with those obtained experimentally during quasi-static forging and heading of hollow spur gear forms using the model material, tellurium lead. The characteristic deformation modes and some salient observations made on working pressures are given and the results commented upon.