EcoGear – Environmental Friendly Bevel Gear Production by Using Pre-Forged Blanks

The project focuses on an alternative approach to produce bevel gears by using pre-forged blanks at the beginning of the process chain with near net shape geometry of the teeth. The use of pre-forged blanks in bevel gear manufacturing allows substantial material savings of ca. 20% and reduces the material that needs to be removed during bevel gear milling by ca. 87%.
Conventional process chains start with a forged blank which have a rotational symmetric geometry. For manufacturing a bevel gear from these blank, the first step is machining of the outer geometry which is followed by the soft machining of the gear flanks. Subsequently the gear is hardened in a heat treatment process and finally ground. Using pre-forged components also introduces new challenges in the process chain like the interrupted cut in turning of the face cone. A precise positioning of the tool in the pre-forged tooth gap for face milling operation would be necessary. Furthermore the hardening distortions during heat treatment may also be affected by using pre-forged blanks due to the banded structure and the segregations in the forging.
When the project goal is reached successfully, the result can lead to an alternative and more environment friendly manufacturing method for bevel gears. This will not only lead to material efficiency but also reduce the energy and resources needed to produce the component. Furthermore this will shorten the machine hour and reduce material to recycle. Tool life in face milling might be increased because less material will be machined. If it can be proved that hardening distortions are better compared to the conventional process chain, tool life might also be increased in grinding due to less stock.