Near Net Shape Spur Gear Forging Using Concave Preform

Necip Fazil Yilmaz,Omer Eyercioglu

doi:10.5755/j01.mech.24.2.19334

Abstract

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%. DOI: http://dx.doi.org/10.5755/j01.mech.24.2.19334

Highlights

Precision forging gives shape to an initial billet, which can be used directly as a part requiring little or no further finishing
Cai et al [14] discussed alternative tool designs, which may be used on a press with only one moving slide and ejection system. They examined the influence of different designs on metal flow and load requirement through experiments and finite element simulation
Velocity distributions and displacement diagrams of four different nodes for each case were considered to discuss the influences of preform geometry

Summary

Introduction

Precision forging gives shape to an initial billet, which can be used directly as a part requiring little or no further finishing. The process of forming has greater potential for large quantity batch production such as required by automotive companies and consumer goods industries. Despite these positive aspects, the economics of fully formed spur and helical gears for power transmission have not yet been proven to be acceptable and cannot be until a robust processing route is established [2]. Cai et al [14] discussed alternative tool designs, which may be used on a press with only one moving slide and ejection system They examined the influence of different designs on metal flow and load requirement through experiments and finite element simulation. Chengliang et al [15] studied on the dimensional accuracy of spur gears

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