In order to increase the efficiency of engines, the latest generation of engines uses so-called double-helical planetary gears. The double-helical gearing is necessary because only it ensures high load absorption and smooth running. On the side of the disadvantages is the demanding production. Common manufacturing processes, such as gear hobbing, require large entry and exit zones for the cutting tools, which usually necessitates a groove between the wheel parts. As a result, double-helical gears are comparatively heavy and have large toothing widths - both of which are disadvantageous for use in engines.
The "CompactGears4Turbo" project aims to develop an innovative process chain for the manufacture of compact and lightweight gears for aircraft transmissions based on 5-axis milling and grinding. Using the proven technology of 5-axis milling, the gears of planetary gear transmissions can be manufactured significantly more compact and lighter. Preliminary studies show that a groove width reduction of 80 % and a weight reduction of 20 % is possible. The process chain to be developed includes digital modelling of the gears (CAD), computer-based process design (CAM), manufacturing of the gear macro geometry (5-axis hard milling), manufacturing of the gear micro geometry 4 (5-axis grinding) and testing of the gears offline (measurement and life tests) as well as through new online approaches (Industry 4.0 - Digital Twin). The developed process chain is made available as a finished technology package consisting of a CAD/CAM module with integrated process knowledge.
The research project is funded by the Federal Ministry of Economics and Energy (BMWi).