A 3D printed gearbox to take the space industry to the next

 The SME has been working since 1997 on offering the best solutions to their customers; this motivation led them to invent and patent an innovative gearbox called NUGEAR (NUtating GEARbox). This gearbox couples the mathematical concept of nutation with bevel gears, reducing the high speed ratios reached by the motors in planes, satellites, rockets and other space applications, while multiplying the power (torque) of the motor.
However, producing the internal components of such a gearbox became a challenge for the Italian SME. While traditional gears are produced through conventional technologies such as hobbing, shaping and milling, the innovative gearbox required new techniques.

 

 

 

Challenge
By applying the CAxMan tools, the inner parts of the gearbox were produced through additive manufacturing, more-generally known as 3D printing. The different partners of the project contributed to the process with their solutions to make it possible.
Mechanical and thermal simulations were performed to test the resistance of the designed parts thanks to the Iso-Geometric Analysis tool provided by Italian institute for Applied Mathematics and Information Technologies (CNR-IMATI). The simulation tool of the International Centre for Numerical Methods in Engineering (CIMNE) allowed then to test the manufacturability of the printing process. Cavities were added to the parts with a dedicated tool from the German partner Fraunhofer IGD, to make them lighter without affecting structural soundness. Once the optimal production parameters were found with the tools developed by CNR-IMATI, the printing process was completed. For that, laser power was applied along a specific path to melt the metal powder and to generate a thin layer. The parts were then 3D scanned with equipment from the Spanish company Trimek, and milled thanks to the CAM interface developed by Missler to obtain the required smoothness and precision.

Benefits
Thanks to the additive manufacturing process and the CAxMan tools, the production of the NUGEAR parts is 40% faster and 20% less expensive, the parts are 25% lighter and more efficient, and the design process is 15% shorter.
These are strong advantages for STAM, because the NUGEAR gearbox can be more competitive and generate higher margins. Also the users of the gearbox will benefit from the increased performances, as the innovative gearbox has a simple configuration with only four gears, smaller size and weight, high reliability and reduction of energy consumption compared to other existing solutions.

Organizations involved
Partners on Caxman project