THE FORGING OF HELICAL GEARS - (I) - EXPERIMENTS AND UPPER-BOUND ANALYSIS

In this paper, the forging of helical gears has been investigated. A p unch and a die are tooth-shaped for the guiding type forging of helica l gears; The punch compresses a cylindrical billet placed in a die ins ert. As a consequence the material of a billet hows into the tooth reg ion. The forging has been analysed by using the upper-bound method. Ki nematically admissible velocity fields have been developed, where an i nvolute curve has been introduced to represent tooth profile of the ge ar. Numerical calculations have been carried out to investigate the ef fects of various parameters, such as modules, numbers of teeth, helix angles and friction factors on the forging of helical gears. Some forg ing experiments were carried out with commercial aluminium alloy to sh ow the validity of the analysis. Good agreements were found between th e predicted values of the forging load and those obtained from the exp erimental results. (C) 1997 Published by Elsevier Science Ltd.