Shape heading of splines and solid spur gear forms:: an analysis and some experiments

To analyse the process of near-net shape heading of splines and solid spur gear forms with the 15 actual involute teeth, each with a pressure angle of 1412°, where in each case these were to be forged integral with the shaft and one end of the initial deforming cylindrical specimen was considered as constrained. Two types of theoretical approaches, i.e. the upper-bound technique (Chitkara and Bhutta. Proceedings of 28 MT DR Conference, 1990. p. 431–42; Chitkara and Bhutta. International Journal of Mechanical Sciences 1995;37(12):1247–68; 1996;38(8–9):891–916) and the slab method of analysis (Chitkara and Bhutta. International Journal of Mechanical Sciences 1996;38(8–9):871–89) employed earlier for simple forging of the product were suitably modified to account for the constraint, were applied. In each case, the estimated theoretical results for the die loads at increasing die movements were compared with those observed experimentally during the quasi-static incremental heading of splines and solid spur gears using tellurium lead as the model material for the specimens. The characteristic deformation modes and some salient observations made on the working pressures during the heading process vis-à-vis simple forging of these products are given and the results are commented upon.