Linear variable-stiffness mechanisms based on preloaded curved beams
Journal
Journal of Mechanical Design
Journal Volume
136
Journal Issue
12
Start Page
122302
ISSN
10500472
Date Issued
2014
Author(s)
Wu, Yi Syuan
Abstract
A machine with an internal variable-stiffness mechanism can adapt its output force to the working environment. In the literature, linear variable-stiffness mechanisms (LVSMs) are rarer than those producing rotary motion. This paper presents the design of a class of novel LVSMs. The idea is to parallel connect two lateral curved beams with an axial spring. Through preload adjustment of the curved beams, the output force-to-displacement curves can exhibit different stiffness. The merit of the proposed LVSMs is that very large-stiffness variation can be achieved in a compact space. The stiffness can even be tuned to zero by assigning the appropriate stiffness to the axial spring. LVSMs with pinned curved beams and fixed curved beams are investigated. To achieve the largest stiffness variation with sufficient linearity, the effects of various parameters on the force curves are discussed. Techniques to scale an LVSM and change the equilibrium position are introduced to increase the usefulness of the proposed design. Finally, the LVSMs are experimentally verified through prototypes.
Subjects
Compliant Mechanism
Curved Beam
Passive Compliance
Variable Stiffness
Zero Stiffness
Compliant Mechanisms
Curved Beams And Girders
Design
Mechanisms
Axial Springs
Curved Beams
Internal Variables
Mechanism-based
Output Force
Passive Compliance
Stiffness Variations
Variable Stiffness
Variable Stiffness Mechanism
Zero Stiffness
Stiffness
Publisher
American Society of Mechanical Engineers (ASME)
Type
journal article