Near Net Shape Spur Gear Forging Using Concave Preform
The objective of this paper is to determine the feasible preform forge geometry for spur gear blank to reduce the forging load requirement. This paper discusses the effects of different preform geometries on the forming behavior of precision forged gear wheel geometry. It is identified that material flow and friction between die and billet are encountered as the major problem in precision forging. Radial flow velocity distributions and displacement diagrams of preform types in accordance with the forming stages were put into perspective. The analyzed preforms were evaluated in terms of forging load versus punch displacement diagrams. The effect of concave preforms on the material flow and the resulting manufacturing quality by finite element simulation in comparison with practical forging tests were analyzed to ensure a proper die filling and load requirements. Finally, a concave preform is proposed for which the forming load could be reduced by 34%.