Cross-Axis Flexure Pivot

Summary

Cross-axis flexure pivots are created by crossing flexures and connecting them with rigid segments at their ends, allowing the opposite ends to rotate relative to each other. Cross-axis flexure pivots can replace pin joints in applications where wear and/or friction need to be low or eliminated.

Assembly

Create your own cross axis flexure pivot by printing two Cross Axis parts, rotating them so the clips are on opposite ends and facing each other, then clipping the two parts together. The two pieces should fit secure with the studs in each corresponding hole and the clips in place.

Application

A version of the cross-axis flexure pivot, the Cylindrical Cross-Axis Flexure Pivot (CCAFP), has been proposed as an ultra-compact flexure capable of being integrated into mechanisms used for minimally invasive surgeries. This CCAFP would create a flexible, hollow wrist at the end of surgical instruments that allows for cables and other components to pass through the inside of the shaft. Potentially, this could decrease the instrument's size while maintaining the instrument's performance.

This cross-axis flexure pivot could also benefit any other application that would require compact and non-intrusive motion components.

A two-degree-of-freedom joint can be created by stacking two cross-axis flexure pivots with their axes of rotation orthogonal to each other.

Other Applications

The BYU CMR group has used this cross-axis flexure in multiple other mechanisms including the following…

2 DOF Fully Compliant Space Pointing Mechanism

Flexlinks: Cross-Axis Flexural Pivot 

Learn More

This design was developed by the Compliant Mechanisms Research Group (CMR) from Brigham Young University (BYU). Follow us at @byucmr on Instagram, @CompliantMechanismsResearchGroup on Facebook, or visit the BYU Compliant Mechanisms Research (CMR) website to learn more about compliant mechanisms.

Technical Information

For in-depth technical information, see the following publications:

Dearden, J., Grames, C., Orr, J., Jensen, B. D., Magleby, S. P., & Howell, L. L. (2018). “Cylindrical cross-axis flexural pivots." Precision Engineering, 51, 604-613. doi:10.1016/j.precisioneng.2017.11.001 

Jensen, B. D., & Howell, L. L. (2002). “The modeling of cross-axis flexural pivots”. Mechanism and Machine Theory, 37(5), 461-476. doi:10.1016/S0094-114X(02)00007-1 

Bilancia, P., Berselli, G., Magleby, S., & Howell, L. (2020). “On the modeling of a contact-aided cross-axis flexural pivot”. Mechanism and Machine Theory, 143 doi:10.1016/j.mechmachtheory.2019.103618  

To learn more about compliant mechanisms in general, see the BYU Compliant Mechanisms Research (CMR) website or these books: Compliant Mechanisms, Handbook of Compliant Mechanisms.

Intellectual Property

The downloadable 3D print files provided here may be used, modified, and enjoyed for noncommercial use. To license this technology for commercial applications, contact:

BYU Technology Transfer Office
3760 Harold B. Lee Library
Brigham Young University
Provo, UT 84602
Phone: (801) 422-6266
https://techtransfer.byu.edu/contact