Synthesis Method for Compliant Mechanisms of High-Precision and Large-Stroke by Use of Individually Shaped Power Function Flexure Hinges

Abstract

Flexure hinge-based compliant mechanisms have many advantages compared to their counterparts with conventional joints. Hence, they are state of the art in numerous precision engineering applications, especially due to their smooth and repeatable motion. The common usage of identical simple notch shapes for all hinges in one mechanism is considerably limiting the stroke. The further design and synthesis are iterative, non-intuitive and often time-consum-ing. Application-specific optimization approaches cannot be generalized. There-fore, a novel and simple synthesis method for compliant mechanisms consisting of easy to model and highly variable power function-shaped flexure hinges is described in this paper. The main approach is to design each hinge individually in dependence of the known rigid-body-based relative rotation angles during mo-tion. A slider-crank path-generating mechanism is used as an example to show the benefits of the synthesis method regarding a high precision as well as a large stroke compared to identically shaped hinges. The method is confirmed by results due to analytical modeling, FEM simulation and experimental investigation.