The geared turbofan technology is one essential way to reduce the fuel consumption, the environmental footprint and the noise pollution of civil aircrafts. An added gearbox between the fan and the low-pressure compressor that reduces the fan speed, which allows higher bypass ratios, achieves the mentioned benefits of geared turbofans. To withstand the high mechanical loads, large double helical gears are used. Gear hobbing and gear grinding require large tool maneuvering spaces. This leads to a larger required space between the single gears of the double helical gear. As a result, the gears are larger and heavier, which leads to a reduced economy of the aircraft. The tool maneuvering space of five-axis milling with solid carbide end mills is much smaller. This enables the design of smaller, lighter and more efficient aircraft engines. However, manufacturing these gears in tolerances better than IT5 is very challenging on five-axis milling machine tools. This paper presents investigations about finish machining of hardened gears on five-axis machine tools. In the investigations performed, varying tool substrates and tool coatings have been investigated together with tool travel paths in order to reduce the tool wear, which is key to achieve the demanded tolerances. Finally, the five-axis milled gears were compared to conventionally manufactured gears on test benches to enable statements regarding the expectable service lives of the manufactured gears.
The geared turbofan technology is one essential way to reduce the fuel consumption, the environmental footprint and the noise pollution of civil aircrafts. An added gearbox between the fan and the low-pressure compressor that reduces the fan speed, which allows higher bypass ratios, achieves the mentioned benefits of geared turbofans. To withstand the high mechanical loads, large double helical gears are used. Gear hobbing and gear grinding require large tool maneuvering spaces. This leads to a larger required space between the single gears of the double helical gear. As a result, the gears are larger and heavier, which leads to a reduced economy of the aircraft. The tool maneuvering space of five-axis milling with solid carbide end mills is much smaller. This enables the design of smaller, lighter and more efficient aircraft engines. However, manufacturing these gears in tolerances better than IT5 is very challenging on five-axis milling machine tools. This paper presents investigations about finish machining of hardened gears on five-axis machine tools. In the investigations performed, varying tool substrates and tool coatings have been investigated together with tool travel paths in order to reduce the tool wear, which is key to achieve the demanded tolerances. Finally, the five-axis milled gears were compared to conventionally manufactured gears on test benches to enable statements regarding the expectable service lives of the manufactured gears.
Durch additive Fertigung können Zerspanwerkzeuge beanspruchungsgerecht und individuell designt und gefertigt werden. Um das volle ökonomische und ökologische Potenzial dieser Werkzeuge auszuschöpfen, ist eine übergreifende Prozesskettenbetrachtung von der Konstruktion über die Fertigung bis zur spanenden Nachbearbeitung nötig. Dabei müssen übergreifende Lösungen und Gestaltungsrichtlinien entwickelt werden.
Additive manufacturing enables an individual design and production of cutting tools that fulfills the requirements. However, the full economic and ecological potential can only be exploited by considering the entire process chain from design and production to post-processing. General solutions and design guidelines have to be developed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.