Compliant Mechanism - activity 1

A GSTP funded activity “COMAM” started in 2018, here CSEM (Switzerland) took advantage of its 30 years expertise in compliant mechanisms for space to design the Compliant Rotation Reduction Mechanism (CRRM). The CRRM allows for rotary motion reduction with a factor of 10, a useful function for scanning, pointing, calibration or flip mirror mechanisms. The Additive Manufacturing of the mechanism was performed by a local company 3D Precision, while the performance tests were performed by Almatech SA.

The activity demonstrated the major advantages of additive manufacturing, such as the design freedom and the possibility to build monolithic complex shapes. This design – integrating 24 flexure blades among which 16 are interlocked (patent pending) to form crossed pivots and 8 intermediate stages – would not be possible in such a small volume without the use of additive manufacturing. Moreover, no alignment is needed between the flexure structures to ensure a proper cinematic. Thanks to a thorough combination of parametric and topology optimizations, the mass and eigen-frequencies were significantly improved and provided a first eigen-mode higher than 550 Hz.