ACCURACY OF INITIALLY-CURVED CROSS-AXIS FLEXURAL PIVOTS

Accuracy of the cross-axis flexural pivot is a fundamental requirement in a variety of applications, from robotics to precision engineering. Many studies have been conducted to improve this feature by investigating the effects of various geometric parameters of the cross-axis pivot, such as orientation of the flexures and position of the intersection point. In the present study, the rotational performance is improved by considering two different features. The first one consists in defining an arrangement based on the position of the flexure centroids, instead of considering the position of their intersection point. The second one consists in introducing an initial curvature for the flexible elements. The constraints introduced by these features lead to the definition of a geometry characterized by two degrees of freedom, that is developed for the design of the curved cross-axis flexural pivot. Different layouts are introduced and nonlinear numerical simulations are carried out to evaluate the pivot accuracy. In particular, accuracy is compared to the one of the straight cross-axis flexural pivot by introducing a proper parameter, based on the determination of the pole of the finite displacements. The results are presented as accuracy design maps, useful to define the geometric layout meeting the accuracy requirements.