Lehrstuhl für Fertigungstechnologie, Universität Erlangen-Nürnberg

Consideration of functionally relevant geometric deviations in the design of metal forming processes for the production of gears by extrusion (DFG - FOR 2271 TP4)

Project Status: Active


The subproject TP4 is part of the DFG research group 2271 - process-oriented tolerance management with virtual validation methods. The aim is the development of a process window for the forming of a steel spur gear in consideration of production-related tolerances and the resulting operational behavior of the material combination steel and plastic. The gear is produced by full-forward extrusion. The challenges of the project are the identification of the influencing parameters of the forming process, which are relevant for the functionality of the demonstrator assembly, as well as to determine the effects of the influencing parameter variation on the running-in behaviour of the gear pair.

At the beginning of the project the extrusion process of the gear is mapped by using the finite element method in order to ensure that the design of the die and pre-stress system meets the requirements. The effects of process-related variability on the geometrical and mechanical properties of extruded gears are investigated more closely by a targeted, experimental variation of the influencing parameters such as the tribological conditions and the workpiece geometry. Taking into account the functionality of the demonstrator assembly the process window for the experimental tests can be derived and the set up FEM model can be validated. Afterwards, the necessary tolerance zones are determined by using variant simulations and the relevant influencing process variables are identified through the development of metamodels.

In the next step the resulting operational behavior of the steel-plastic gearing is examined on a gear test stand.The aim is to determine the influence of the component properties of the steel sprocket on the wear behaviour of the plastic gear. Therefore, the wear of the plastic gear and the changes of the component geometry and surface during the running-in process are examined.  


The project is carried out in cooperation with the other sub-projects in this research group listed below:

TP1: Virtuelle und experimentelle Toleranzuntersuchungen abweichungsbehafteter Baugruppen
am Lehrstuhl für Konstruktionstechnik (KTmfk)

 TP2: Fuzzy-arithmetische Modellierung von Prozessen mir unsicheren Parametern
am Lehrstuhl für Technische Mechanik (LTM)

 TP3: Bestimmung der Messunsicherheit und systematischer Gestaltabweichungen für eine funktionsorientierte Toleranzvergabe
am Lehrstuhl für Fertigungsmesstechnik (FMT)

TP5: Analyse leistungsrelevanter, prozessbedingter Struktur- und Gestaltabweichungen von Kunststoffzahnrädern zur anwendungsgerechten Auslegung am Lehrstuhl für Kunststofftechnik (LKT)


Research Groups



    • Merklein, M.; Hagenah, H.; Lorenz, R.:
      Influence of the Coating Process on the Tribological Conditions during Cold Forging with a MoS2 Based Lubricant.
      AIP Conference Proceedings; https://doi.org/10.1063/1.5034867 1960(2018)1, pp. 040013

    • Merklein, M.; Hagenah, H.; Lorenz, R.:
      Experimental evaluation of cold forging lubricants using double cup extrusion tests.
      Materials Science Forum 918(2018), pp. 65-70

    Letztes Update: 06.08.2018