Consideration of functionally relevant geometric deviations in the design of metal forming processes for the production of gears by extrusion
Third Party Funds Group - Sub project
Start date : 01.04.2016
End date : 31.03.2023
Overall project details
Overall project
FOR 2271: Prozessorientiertes Toleranzmanagement mit virtuellen Absicherungsmethoden (FORTol)
June 1, 2016 - Aug. 14, 2023
Overall project speaker:
Project details
Short description
Short description
The subproject TP4 is part of the DFG research group 2271 - process-oriented tolerance management with virtual validation methods.
The component properties of metallic gears have a significant influence on the wear behavior of dry-running material pairings. Against the background of the advantages of forming production, the targeted adaptation of the production-related component properties during the extrusion process shows potential. Within the research group FOR 2271, parameters influencing the geometrical and mechanical properties of extruded gears are identified. The effects of the forming induced component properties on the operational behavior are investigated and the underlying wear mechanisms are determined. Finally, correlations between component properties and operational behavior as well as recommendations for the design of the extrusion process are derived.
Scientific Abstract
The subproject TP4 is part of the DFG research group 2271 - process-oriented tolerance management with virtual validation methods.
In order to achieve an integrated tolerance management, it is necessary to consider not just the process-related causes of geometric component deviations but also the deviations resulting from operation. The aim of the subproject is to identify variables influencing the operational behavior of extruded gears in the material pairing metal-plastic and to derive functional relationships between the process-related component properties and the resulting wear behavior of the pairing. Based on these findings, an operation-optimized design of the extrusion process for the production of ready-to-use gears is to be carried out and compliance with the function-relevant tolerances over the service life is to be ensured. Within the framework of the research group's overall objectives, an important contribution is made to accomplish a holistic approach within process-orientated tolerance management.
The project is based on the findings of the first funding period. During this period, the focus was on the identification of influencing variables and process-related fluctuations and its effects on the geometric accuracy and mechanical properties of steel gears produced by full forward extrusion. For this purpose, the impact extrusion process was mapped using the finite element method and a reference process was designed. The FEM model has been validated by forming experiments. The validated model was then used to identify influencing variables on the component and process side. The effects of process-related fluctuations on the resulting geometric and mechanical component properties were investigated by further forming tests. From the results, a process window was derived to ensure compliance with the functionally relevant tolerances.
In the second funding period, the effects of the process-related geometric, mechanical and tribological properties of extruded gears on geometric deviations as a result of the characteristic wear behavior of the metal-plastic material pairing during operation will be investigated. The resulting decrease in tooth width limits the adherence to the tolerances as well as the lifetime of the pairing due to tooth wear. The investigations regarding the wear behavior of the material pairing metal-plastic of the first funding period show that the properties of the metallic partner have a significant influence on the wear of both gears. Against this background, the choice of the gear material and the specific adaptation of the application-relevant component properties of the gearing within the extrusion process offer potential. Within the framework of the sub-project, the essential wear mechanisms within the material pairing are identified and the application-relevant component properties of the metallic gearing are determined on a transmission test bench. Finally, recommendations regarding the operationally optimized design of extrusion processes are derived and verified.
Involved:
Marion Merklein
Project Leader
Hinnerk Hagenah
Project Leader
Andreas Rohrmoser
Project Member
Robby Lorenz
Project Member
