The net-shape forming of gears

Over recent years vigorous developments have been undertaken to enable the production of gears and gear forms by forming methods. The driving force behind this activity has been, in common with other areas of component manufacture, greater added value. These developments are leading to the commercial feasibility of producing gear tooth forms of high quality, ready for use. For applications where extreme high quality of tooth form is not necessary, such as automotive differentials, forged gear forms can be employed without further machining. Because the dimensional quality required of the running teeth of gears in automotive gear boxes is high as yet only machined tooth forms are sufficiently accurate. This paper describes the background to the research on the forging of spur and helical gear forms with particular attention on the production of high quality gears for land transport applications.