Design and Analysis of a New 7R Single-Loop Mechanism with 4R, 6R and 7R Operation Modes

Xiuyun He, Xianwen Kong*, Guangbo Hao, James Ritchie

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingChapter

18 Citations (Scopus)


The design and analysis of a new 7R single-loop multi-mode mechanism (SLMMM) is presented in this paper. The 7R SLMMM is obtained by inserting one R joint into a line and plane symmetric overconstrained Bricard 6R linkage. The new mechanism has three types of operation modes with three different numbers of effective joints including 4R, 6R and 7R modes, while most other SLMMMs only have one or two numbers of effective joints in all operation modes. The kinematic mapping method and the algebraic approach are applied to implement the kinematic analysis of the 7R SLMMM. Motion curves are plotted to illustrate the operation modes and transition configurations. Meanwhile, CAD configurations are presented to verify these motion curves. As a by-product of this work, a new overconstrained 6R mechanism has been identified, which is in fact the proposed 7R mechanism in one of its 6R operation modes.

Original languageEnglish
Title of host publicationAdvances in Reconfigurable Mechanisms and Robots II
Number of pages11
ISBN (Electronic)978-3-319-23327-7
ISBN (Print)978-3-319-23326-0
Publication statusPublished - 2016

Publication series

NameMechanisms and Machine Science
ISSN (Print)2211-0984
ISSN (Electronic)2211-0992


  • 7R Single-loop multi-mode mechanism
  • Algebraic geometry
  • Kinematic mapping
  • Operation modes
  • Transition configurations

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering


Dive into the research topics of 'Design and Analysis of a New 7R Single-Loop Mechanism with 4R, 6R and 7R Operation Modes'. Together they form a unique fingerprint.

Cite this