The art of flexure mechanism design Coll. P U POLYTEC ROM

Flexure mechanism design is an art, and this book provides the theoretical and practical foundation for scientists and engineers to express their creativity in this field. Flexure mechanisms, also known as compliant mechanisms, rely on the elasticity of matter to provide motion to mechanism linkages. Flexure mechanisms eliminate the disadvantages of classical joints: friction, wear, lubrication and play, while permitting monolithic design. Flexure-based mechanisms have gained prominence in a wide variety of fields including robotics, surgical instrumentation, aerospace, astronomy, particle accelerators, metrology and horology.

This book establishes a conceptual framework for the design of flexure-based articulated structures. Topics featured deal with the theoretical foundations for the design of translational and rotational flexures, the simple kinematic analysis of flexure-based mechanisms, and advanced kinematic approaches to the design of complex flexure-based mechanisms using modules in parallel or serial arrangements.

The book also features detailed examples of long stroke flexure mechanisms used in metrology applications, and a detailed example of planar flexure mechanisms having out of plane functionality and used in surgical applications. This book aims to provide scientists and engineers with a conceptual tool, an analytic methodology and the key references for their precision engineering needs

Preface
Foreword

1 - Introduction – Flexure bearing importance – Flexible element classification – Book goals and structure – Topic delimitation

I - Basic Flexures
2 - Underlying theory
. Basic assumptions
. Allowable deflections
. Stiffnesses
3 - Flexure joint elements
. General considerations
. Leaf springs
. Rods
. Torsion bars
. Circular notch hinges
4 - Translational flexures
. Two parallel leaf spring stage
. Overconstrained stage with four parallel leaf springs
. Four prismatic notch hinge stage
. Four circular notch hinge stage
. Conclusion on linear translation bearings
5 - Rotational flexures
. Separate cross spring pivot
. Joined cross spring pivot
. RCC pivot with two leaf springs
. RCC pivot with four notch hinges
. Cross pivot with four notch hinges
. Comparison of the pivots
. Radial loads
. Overconstrained pivot with three leaf springs

II - Flexure Mechanisms
6 - Flexure structures
. Kinematics
. Choice of materials
. Working envelope
. Stiffnesses
7 - Modular design of flexure-based robots
. Introduction
. Concept of modular kinematics
. Reduced solution catalogue for ultra-high precision
. Mechanical design of the building bricks
. Case study: 5-DOF ultra-high precision robot
. Ultra-high precision parallel robot family
. Conclusion
. Final note
8 - Rectilinear flexure mechanisms
. Introduction
. Rectilinear kinematics
. Sarrus guiding mechanism
. 13-hinge stage mechanism
. Analysis and comparison
. Application to the watt balance
. Conclusions
9 - Out-of-plane flexure mechanisms
. Introduction
. Example: design of an active cardiac stabiliser
. In the vicinity of singularities
. Optimisation of the spherical compliant joint
. Exploiting the singularities of parallel mechanisms
. Selection of an actuation mechanism
. Integration of the three mechanisms in two planes
. Conclusion

Afterword
Bibliography
Index