Tool life and productivity improvement: Through cutting parameter setting and tool design in dry high-speed bevel gear tooth cutting

The introduction of carbide tools and hard coatings has led to a quantum leap in material removal rates and tool life in manufacturing automotive-sized bevel and hypoid gears, as the tools and coatings have in other areas of machining technology (Refs. 1-6). Further benefits of the new techology are the ability to abandon the use of coolant and the improvement of quality, which partly goes back also to advancements in the machine tool technology and the implementation of quality loops in manufacturing (Ref. 3-4 and 7-13). However, the number of influential factors on manufacturing cost per piece is high, and an in-depth process analysis and understanding has not yet been established in many areas. Yet this fundamental knowledge is required to show the right direction for further enhancements of economic efficiency and productivity, since thorough process development is difficult to conduct during and after the start of production in an industrial environment (Ref. 13). Therefore, thorough machining investigations are conducted at WZL within the scope of an AiF research project (13713 N/1) on high speed bevel gear machining. This article presents some of the findings of cutting investigations at WZL in which the correlation of cutting parameters, cutting materials, tool geometry and tool life have been determined. Finally, the idea for a new WZL face milling tool concept, which has some significant theoretical advantages over state-of-the-art tool systems, is presented.