a study of precision forging of steel spur gears: upper bound model and experiments

precision forging process is widely used for the production of spur gears due to its advantages such asimproved strength and surface finish, little waste of materials and reduction in the machining time ofthe gear. an important aspect of precision forging process is the load required to perform the processsuccessfully and design the forging tools. in this research, a new kinematically admissible velocityfield was presented to predict the precision forging pressure of the steel spur gear by upper boundanalysis. the model considered the shape of tooth profile, the number of teeth and friction coefficient.the accuracy of the model was verified using experimental results and a good agreement was foundbetween the two sets of results at the filling stage of the precision forging process. also, the results werecompared with the models developed by other researchers, showing that the teeth profile considered inthis study was much closer to the actual profile of the gear.