A spatial eight-bar linkage and its association with the deployable platonic mechanisms

Wei, G; Dai, JS

Abstract

This paper presents for the first time a novel two degrees of freedom (2-DOF) single-looped dual-plane-symmetric spatial eight-bar linkage with exact straight-line motion. Geometry and kinematics of the eight-bar linkage are investigated and closed-form equations are presented revealing the exact straight-line motion feature of the linkage on the condition that two symmetric inputs are given. In order to secure two symmetric inputs, a geared eight-bar linkage is then proposed converting the linkage into a 1-DOF linkage of exact straight-line motion. The direction of the straight-line motion produced by the proposed eight-bar linkage is changeable and is only dependent on the structure parameters of the two pairs of V-shaped R-R dyads of the linkage. Further, the proposed eight-bar linkage is applied to the synthesis and construction of a group of deployable Platonic mechanisms with radially reciprocating motion. The virtual-center-based (VCB) method is presented for the synthesis and prototypes of the deployable Platonic mechanisms are fabricated verifying the mobility and motion of the proposed mechanisms.

Citation

Wei, G., & Dai, J. (2014). A spatial eight-bar linkage and its association with the deployable platonic mechanisms. Journal of Mechanisms and Robotics, 6(2), 021010. https://doi.org/10.1115/1.4025472

• Journal Article Type: Article
• Acceptance Date: Sep 2, 2013
• Online Publication Date: Mar 12, 2014
• Publication Date: May 1, 2014
• Deposit Date: May 29, 2015
• Journal: Journal of Mechanisms and Robotics
• Print ISSN: 1942-4302
• Electronic ISSN: 1942-4310
• Publisher: American Society of Mechanical Engineers
• Peer Reviewed: Peer Reviewed
• Volume: 6
• Issue: 2
• Pages: 021010
• DOI: https://doi.org/10.1115/1.4025472
• Publisher URL: http://dx.doi.org/10.1115/1.4025472
• Related Public URLs: http://mechanismsrobotics.asmedigitalcollection.asme.org/journal.aspx