Design and analysis of a high-accuracy flexure hinge.

Min Liu,Sergej Fatikow,Xianmin Zhang

doi:10.1063/1.4948924

Abstract

This paper designs and analyzes a new kind of flexure hinge obtained by using a topology optimization approach, namely, a quasi-V-shaped flexure hinge (QVFH). Flexure hinges are formed by three segments: the left and right segments with convex shapes and the middle segment with straight line. According to the results of topology optimization, the curve equations of profiles of the flexure hinges are developed by numerical fitting. The in-plane dimensionless compliance equations of the flexure hinges are derived based on Castigliano's second theorem. The accuracy of rotation, which is denoted by the compliance of the center of rotation that deviates from the midpoint, is derived. The equations for evaluating the maximum stresses are also provided. These dimensionless equations are verified by finite element analysis and experimentation. The analytical results are within 8% uncertainty compared to the finite element analysis results and within 9% uncertainty compared to the experimental measurement data. Compared with the filleted V-shaped flexure hinge, the QVFH has a higher accuracy of rotation and better ability of preserving the center of rotation position but smaller compliance.

Highlights

A flexure hinge consists of a flexible, slender region between two adjacent rigid parts that undergo relative limited rotation in a mechanism and is the important constituent of lumped compliant mechanisms
The analytical results are within 8% uncertainty compared to the finite element analysis results and within 9% uncertainty compared to the experimental measurement data
This paper addresses the theoretical analysis of quasi-V-shaped flexure hinge (QVFH)

Summary

Introduction

A flexure hinge consists of a flexible, slender region between two adjacent rigid parts that undergo relative limited rotation in a mechanism and is the important constituent of lumped compliant mechanisms. Flexure hinges have several advantages over conventional rotational joints due to being monolithic with the rest of the mechanism.. Flexure hinges have several advantages over conventional rotational joints due to being monolithic with the rest of the mechanism.1,2 They have no friction losses, no need for lubrication, and no backlash; they do have compactness. Right circular flexure hinges were extensively employed in compliant mechanisms. Wu and Zhou deduced more concise design equations for rectangular singleaxis hinges and right circular hinges. Yong et al. presented a guideline for selecting the most accurate equations for circular flexure hinges design calculations and formulated general empirical compliance equations for a wide range of t/R ratios (0.05 ≤ t/R ≤ 0.8)

Methods

Results

Conclusion