ORIGINALARBEITEN/ORIGINALS DOI 10.1007/s10010-017-0249-6 Forsch Ingenieurwes (2017) 81:265–269 Manufacturing processes of multi-component gearwheels R. Meissner 1 · T. Benkert 2 · M. Hiller 2 · M. Liewald 1 · W. Volk 2 Received: 5 May 2017 © Springer-Verlag GmbH Deutschland 2017 Abstract Gearwheels in automotive applications are usu- ally designed as monolithic parts. Adapting the concept of multi-component design to those applications allows to re- duce the car’s weight. The presented multi-component gear- wheels consist of three pieces: a gear ring including teeth, a shaft and a wheel body that connects shaft and gear ring. Two gearwheel concepts as well as the corresponding join- ing strategy of gear ring and wheel body are introduced in this paper. First manufacturing concept is about the wheel body stapled by fine blanked sheet metal layers. Gear ring and wheel body are joined by a press fit. The second con- cept focuses on manufacturing the wheel body by lateral extrusion of a metal disk. Using the gear ring as the die in the forging tool allows manufacturing the wheel body as well as joining wheel body and gear ring simultaneously. The authors investigate both production processes virtually and compare both gearwheels designs regarding load and lightweight potential. 1 Introduction Due to increasing stringent restrictions concerning the CO2 emissions until the year 2020, the automobile manufac- turers aim at reducing their cars’ emissions. Lightweight design is an important objective to fulfill the upcoming re-  R. Meissner robert.meissner@ifu.uni-stuttgart.de 1 Institute for Metal Forming Technology (IFU), University of Stuttgart, Holzgartenstraße 17, 70174 Stuttgart, Germany 2 Chair of Metal Forming and Casting (utg), Technical University of Munich, Walther-Meißner-Straße 4, 85748 Garching, Germany strictions. While past efforts focused on the car body, recent investigations show high potential for weight reduction of the powertrain [1]. Gearwheels in the gearbox will serve as an example here. They are made from high strength steels due to high loads close to the tooth root [2]. Apart from these small areas, the material’s capabilities stay unused. Multi-component (differential) design (Fig. 1) allows to re- duce the gearwheel’s weight while enhancing material use. A gear ring made from high strength steel supports the high local loads mentioned above and a lightweight wheel body transfers the torque from the gear ring to the shaft. Gear ring and wheel body are joined by a shaft-hub joint. In this paper, it is investigated how the additional shaft-hub joint and a lightweight wheel body affect the transferable torque of the gearwheel. Two different wheel body concepts that are based on the manufacturing processes forging and sta- pling fine blanked sheet metal are introduced. Gear ring and shaft provide geometrical and mechanical boundary condi- tions that have to be considered while designing the wheel bodies and the corresponding manufacturing processes. Ge- ometry and mechanical properties of gear ring and shaft are derived from the gearing of the fourth gear of a commer- cial vehicle. This reference gearing leads to a gear ring with characteristic values shown in Fig. 1. The gearing’s module is 2.00 mm with a helix angle of 30° and the shaft corre- sponds to DIN 5480 WA 30 × 1 × 28 x h6 × 9e. The inner side of the forged wheel body is machined after forging to use the same shaft geometry for testing. Stapled sheet metal wheel bodies use gear rings with cylindrical inner geometry. For forged wheel bodies the gear ring’s inner ge- ometry is of a more complex shape. A general objective is to choose a wheel body design that reduces the gearwheel’s weight by at least 25%. K