To meet the future goals of higher productivity and lower production costs, the cutting speeds and feeds in modern gear bobbing applications have to increase further. In several cases, coated carbide tools have replaced the commonly used high-speed steel (HSS) tools. Because this leads to production processes working on the upper limit of their performance capabilities, the tolerances for deviations from the optimum process settings are getting smaller. To deal with this situation, especially in carbide bobbing, all factors that have an influence on the bobbing process - like the workpiece geometry, the process parameters and especially the tool design-have to be taken into account if a high level of process performance is desired. This essay will present a case study based on two industrial gearings. The investigations include the influence of coating, substrate, layout and edge preparation on tool performance. In detail, fundamental baseline trials using "fly-cutter bobbing" will be presented. Besides several coating and substrate combinations, different tool layouts have also been tested. To verify the results, real bobbing trials under industrial production conditions have been carried out as well. Finally, the potential of modern simulation and calculation programs to optimize bobbing processes will be shown. The report aims to give new impulses to the tool design of carbide hobs and to an optimized process setting.
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