Development of a displacement-insensitive bevel gearing system generated through additive manufacturing

• Applicant: Professor Dr.-Ing. Matthias Kreimeyer
• Subject Area: Engineering Design, Machine Elements, Product Development
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 556956039

Conventionally manufactured bevel gears are usually sensitive with regard to the displacement of the flanks as a result of manufacturing-related geometric deviations and load-related deformations. The core idea is to improve on the shape of bevel gears to prevent said displacement best possible. This allows to transfer such gears to a wider range of use cases. In part of the planned investigations, the design method developed in a previously completed DFG research project for non-conjugate involute gears in arbitrary shaft positions with shaft angles up to about 20° will therefore be transferred to bevel gears. The contact pattern, which is defined by an analytically describable gear geometry and can be adjusted in position and up to full size, enables the targeted compensation of flank displacements. This leads to flank geometries that can hardly or not at all be produced conventionally. In contrast, additive manufacturing enables complex free-form shapes and makes it possible to produce these tooth shapes that are insensitive to displacement. The disadvantage is the necessary surface finishing due to insufficient surface quality. Finishing with conventional grinding processes is typically not feasible for these complex free forms (i.e. the tooth shape) in terms of production. Based on preliminary investigations on the lapping of additively manufactured gear pairs, a process for generating complex tooth forms with sufficient accuracy will be developed in a further part of the planned investigations. With additive manufacturing and targeted finishing to achieve the designed flank geometry, this will enable the generation of the displacement-insensitive bevel gears. The combination of these two investigations (i.e., AM-based shape optimization and targeted finishing to obtain ideal surface quality), a design guideline can be derived for the development of displacement insensitive bevel gears. The targeted design in terms of contact pattern position and size in combination with additive manufacturing and an adapted finishing process can thus be used to realize an optimum gear geometry. Hence, the primary objective of the proposed project is to derive a design method for the devel-opment of bevel gears that are insensitive to displacement and whose gear geometry can be described independently of conventional manufacturing processes. Furthermore, adapted finishing methods with sufficient accuracy for the additive manufacturing of these complex tooth geometries are investigated. The overall aim is to show that, in general, additively manufactured complex functional surfaces can be produced very accurately with adapted finishing processes and represent an alternative to today’s production processes and their limitations towards conventionally not finishable shapes.

• DFG Programme: Research Grants
• International Connection: Switzerland
• Partner Organisation: Schweizerischer Nationalfonds (SNF)
• Cooperation Partner: Dr.-Ing. Hans-Jörg Dennig