0
Technical Brief

Compact Arrangements of Cable-Pulley Type Zero-Free-Length Springs

[+] Author and Article Information
Yu-Heng Ou

Department of Mechanical Engineering,
National Taiwan University,
No. 1, Sector 4, Roosevelt Road,
Taipei 10617, Taiwan
e-mail: r03522602@ntu.edu.tw

Dar-Zen Chen

Department of Mechanical Engineering,
National Taiwan University,
No. 1, Sector 4, Roosevelt Road,
Taipei 10617, Taiwan
e-mail: dzchen@ntu.edu.tw

1Corresponding author.

Manuscript received June 27, 2016; final manuscript received April 6, 2017; published online May 9, 2017. Assoc. Editor: Marc Gouttefarde.

J. Mechanisms Robotics 9(4), 044502 (May 09, 2017) (7 pages) Paper No: JMR-16-1188; doi: 10.1115/1.4036515 History: Received June 27, 2016; Revised April 06, 2017

A methodology to develop springs with zero-free-length (ZFL) characteristics is presented, and the configurations for placing the springs precisely on the manipulators are introduced. A spring–string arrangement installed between two separate links of a serial-type manipulator is employed and is divided into three regions for mounting, tensioning, and placing the string. The springs can develop ZFL characteristics if adequate length is ensured for mounting the springs. To shorten the length for placing strings, a reference length acquired from the link configurations is utilized. The minimization of the placing length can therefore be described clearly. Because the overextended springs and links occupied the workspace of the other links as a result of the long mounting length, the springs are reorganized using pulleys and wire winding configurations to shorten the mounting length. The springs can then be arranged in alignment on the links. As achieved with this additional arrangement, comprehensive spring configurations on the manipulators can be shown. Two examples are presented after deriving the spring configurations for ZFL characteristics and the configurations with wire winding, respectively.

FIGURES IN THIS ARTICLE
<>
Copyright © 2017 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

Spring attached between links i and k of the kinematic chain: (a) link configurations and (b) spring configurations

Grahic Jump Location
Fig. 2

Mounting length and pseudomounting length of springs on the adjacent links

Grahic Jump Location
Fig. 3

Mounting length and pseudomounting length of springs on the proximal link

Grahic Jump Location
Fig. 4

Theoretical configurations of the springs

Grahic Jump Location
Fig. 5

Practical configurations of ZFL springs

Grahic Jump Location
Fig. 6

Practical configurations of the individual spring for ZFL characteristics: (a) spring S12, (b) spring S24, (c) spring S34, and (d) spring S14

Grahic Jump Location
Fig. 7

Spring elongation and its workspace (in gray blocks) in three cases: (a) curve of pretension springs, (b) curve of original springs, and (c) curve of stronger springs

Grahic Jump Location
Fig. 8

Reel-based wire winding configurations

Grahic Jump Location
Fig. 9

Practical configurations of springs with the use of wire winding

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In