Single piece compliant spatial slider–crank mechanism

• Single piece spatial compliant slider-crank mechanism is introduced.
• Deflections of the multiple axis flexural hinges are determined as bending and twist separately.
• Mathematical model is verified with experiments.

This paper presents a novel study on the analysis of the “single piece” compliant spatial slider–crank mechanism. In the previous study performed by the authors, a “partially compliant” version of the spatial slider–crank mechanism was introduced. Since there was a rigid ball joint in that case, there was no torsional loading at flexural hinges. For the single piece case, there is no ball joint in the structure of the mechanism. Therefore, there is also torsion available at multiple axis flexural hinges. Analysis and design of such a compliant mechanism is different from the partially compliant case. In this study, deflections of the multiple axis flexural hinges are determined as bending and twist separately. Fundamental angles for manufacturing a mechanism in a particular position are obtained. A real model is built and results of the mathematical model are verified with experiments. A fatigue test is performed for flexural hinges of a similar mechanism. After one and a half million cycles it is monitored that there is no indication of failure.