Process modification of bevel gear forging using three-dimensional finite element analysis

Bevel gear forging has several advantages as compared with conventional gear forming by a cutting process. For example, it reduces the material loss, and the production lead-time and also has the advantage in product quality improvement of using plastic material flow in the gear teeth. In general, gear forging has a process sequence including preforming and final forming because of the geometrical complexity of its tooth profile. Despite the importance of designing the process sequence, conventionally it has been done by the design expert with exhaustive trial-and-error. Recently, there have been many trial approaches to find the optimal process and die design, and to acquire the quality-related information after forming from simulation using the FEM. In this study the bevel gear forging process is simulated by three-dimensional FEM based on rigid–plastic material modeling, and it is applied to the die design consideration to improve the product quality and to secure the effective material flow. Finite element simulations are performed for two types of bevel gear forging processes to find a defect-free forging process, and comparisons are made between the two processes. It has been thus shown how an improvement can be made through an improved design using finite element simulation.