Objectives

The objective of this project is to design, build and test a harmonic drive able to work at very low temperatures –cryogenic conditions- according to the  EC-ESA-EDA JTF Final Report , List of Urgent Actions APPENDIX Page 5/10 and the corresponding work programme topic FP7-SPACE 2010-1, Activity 9.2 Strengthening the foundations of Space science and technology, Area 9.2.2: Research to support space transportation and key technologies. SPA.2010.2.2-01 Space technologies.

The objective of the project is to design, build and test in a relevant environment a magnetic-superconductor cryogenic non contact harmonic drive (MAGDRIVE) TRL5. This harmonic drive is a mechanism provided with an input axle and an output hub with a great reduction ratio and it will be able to function at cryogenic temperatures. It is based on a non-contact interaction between magnets, soft magnetic materials and superconductors. Therefore the drive has not any wearing neither fatigue and it does not need any lubrication. It will greatly increase the life time of the drives. As drives are profusely used in many different fields the result of this project is a qualitative jump that will open many opportunities.

 

This harmonic drive is based on “non-contact magnetic teeth” instead of fitting teeth on a flexural wave as conventional harmonic drives are based on. Non-contact magnetic teeth are activated by a magnetic wave (similar to an electrical engine). This would solve the problems of contact wearing and mechanical fatigue.

Superconductors are used for non-contact bearings and for shielding the magnetic fields to avoid electromagnetic interferences or emission. The latest available technologies are used for selecting and manufacturing magnetic and superconducting materials as well as for designing the magnetic-superconductor non-contact mechanisms.

In order to achieve a TRL 5 a prototype and a breadboard has been designed, built and tested at a temperature below 60 K. Performances and real mechanical properties –maximum speed, speed ratio, torques and load capability, as well as clearances, position and orientation of the moving parts- are characterized in order to establish the criteria for the usage of these MAGDRIVEs in space and other applications. The mechanism is intrinsically “cryogenic friendly” and it is expected to have a better performance at a lower temperature.