Modelling and upper bound analysis of involute spur gear precision forging

ABSTRACT: Geometric modelling of involute spur gears, precision forging process simulation and upper bound analysis are the subjects of this paper. Computer programs for the geometric modelling have been written with Visual Basic in SolidWorks macro. Module, teeth number, pressure angle, gear height and bore radius of the spur gear were input to a parametric computer program and then spur gear solid model is constructed. Using spur gear model, billet dimensions, the die cavity, the punch and the ejector are modelled automatically. Forming load is calculated using the upper bounds. For upper bound analyses, half pitch of a tooth with involute curve has been divided into six deformation zones. A velocity field in which bulging of the tooth form is considered has been proposed. The obtained forging load was compared with experimental results carried out in literature and simulated with SuperForge commercial code.