A Novel Family of Leaf-Type Compliant Joints: Combination of Two Isosceles-Trapezoidal Flexural Pivots

Abstract

The leaf-type isosceles-trapezoidal flexural (LITF) pivot consists of two compliant beams and two rigid bodies. For a single LITF pivot, the range of motion is small while the center-shift is relatively large. The capability of performance can be improved greatly by the combination of two LITF pivots. Base on the pseudorigid-body (PRB) model of a LITF pivot, a method to construct the double-LITF pivots is presented by regarding a single LITF pivot as a the configurable flexure module. The trends of the center-shift are mainly considered by using this method with the combination of two LIFT pivots. Eight types of double-LITF pivots are synthesized. Compared with the single LIFT pivot, the stroke becomes larger, and stiffness becomes smaller. Four of them have the increased center-shift. The other four have the decreased center-shift. Two of the double-LITF pivots are selected as the examples to explain the proposed method. The comparison between PRB model and finite element analysis result shows the validity and effectiveness of the method.