Method to minimize flank burrs in gear cutting using skiving as an example

• Applicant: Professor Dr.-Ing. Volker Schulze
• Subject Area: Metal-Cutting and Abrasive Manufacturing Engineering
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 515118675

The aim of the research project is to develop a method to reproducibly achieve the usually wear-related reconditioning limit of skiving tools without the flank burr formation (=FBF) exceeding a critical tolerance value for the function or further processing of the manufactured gear. As a result, skiving tools, which are taken out of service in today's industrial practice up to 80% before their wear-related service life due to unpredictable FBF, can be used significantly longer, production planning can be simplified and resources can be conserved. It is postulated that FBF in skiving of internal gears can be predicted and controlled depending on the local cutting conditions and their variation. Thus, FBF can be minimized by specific process- and tool-side adjustments. In a first step, the local cutting conditions relevant for the FBF are narrowed down by reproducing the FBF observed in preliminary tests in an analogy test. The analogy test allows in-process measurement of process forces together with observation of the FBF with a high-speed camera, whereby the material flow and its direction during the FBF can be analyzed in detail. In a second step, the results are used in a two-stage simulation of the FBF with the modelling of deviations of real skiving tools, which aims to identify the relevant parameter variations and mechanisms for the FBF. In a third step, a phenomenological description of the FBF is derived on the basis of the simulation results and further high-speed recordings. In addition, a systematic experimental variation of identified influencing factors on the mechanisms relevant to burr formation is carried out in the analogy test with the aim of recording quantitative correlations and sensitivities that permit the subsequent derivation of burr minimization strategies. In parallel, the identified mechanisms are compared with and differentiated from those known from literature. Subsequently, existing strategy approaches for the reduction of the FBF will be evaluated and further developed with the help of simulations. Thereby, the application-related question is addressed to what extent the skiving process has to be influenced in order to prevent function-critical FBF until the tool reaches its usual reconditioning limit. In the last step, the burr minimization approaches are tested in the skiving process with a complete workpiece in order to finally validate the findings and to demonstrate the potential for effectively reaching the reconditioning limit. Finally, the findings are formulated on the basis of mechanisms and parameters so that they can be directly transferred to other burr-critical processes.

• DFG Programme: Research Grants