0
Technical Brief

Synthesis of Constant Torque Compliant Mechanisms

[+] Author and Article Information
Hari Nair Prakashah

Department of Mechanical Engineering,
Texas A&M University-Kingsville,
Kingsville, TX 78363
e-mail: hari.nair9@gmail.com

Hong Zhou

Department of Mechanical Engineering,
Texas A&M University-Kingsville,
Kingsville, TX 78363
e-mail: hong.zhou@tamuk.edu

Manuscript received May 22, 2016; final manuscript received September 26, 2016; published online October 25, 2016. Assoc. Editor: Larry L Howell.

J. Mechanisms Robotics 8(6), 064503 (Oct 25, 2016) (8 pages) Paper No: JMR-16-1148; doi: 10.1115/1.4034885 History: Received May 22, 2016; Revised September 26, 2016

Constant torque compliant mechanisms produce an output torque that does not change in a large range of input rotation. They have wide applications in aerospace, automobile, timing, gardening, medical, and healthcare devices. Unlike constant force compliant mechanisms, the synthesis of constant torque compliant mechanisms has not been extensively investigated yet. In this paper, a method is presented for synthesizing constant torque compliant mechanisms that have coaxial input rotation and output torque. The same shaft is employed for both input rotation and output torque. A synthesized constant torque compliant mechanism is modeled as a set of variable width spline curves within an annular design domain formed between a rotation shaft and a fixed ring. Interpolation circles are used to define variable width spline curves. The synthesis of constant torque compliant mechanisms is systematized as optimizing the control parameters of the interpolation circles of the variable width spline curves. The presented method is demonstrated by the synthesis of constant torque compliant mechanisms that have different number of variable width spline curves in this paper.

Copyright © 2016 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

Three typical T–θ relationship curves

Grahic Jump Location
Fig. 2

The realistic T–θ relationship curve

Grahic Jump Location
Fig. 3

The output torque deviation from its desired constant value

Grahic Jump Location
Fig. 4

The annular design domain with outside fixed ring

Grahic Jump Location
Fig. 5

The annular design domain with inside fixed ring

Grahic Jump Location
Fig. 6

Five interpolation points and their interpolation polyline

Grahic Jump Location
Fig. 7

The cubic spline curve from the interpolation points of Fig. 6

Grahic Jump Location
Fig. 8

The wide cubic spline curve from the cubic spline curve of Fig. 7

Grahic Jump Location
Fig. 9

The wide cubic spline curve with cusp

Grahic Jump Location
Fig. 10

Five interpolation circles and their interpolation polyline

Grahic Jump Location
Fig. 11

The variable width spline curve from the interpolation circles of Fig. 10

Grahic Jump Location
Fig. 12

The design domain of the synthesized compliant mechanism

Grahic Jump Location
Fig. 23

The assembly model of the compliant mechanism and base plate

Grahic Jump Location
Fig. 24

The physical model of the assembled compliant mechanism and base plate

Grahic Jump Location
Fig. 25

TSD-50 digital torque screwdriver

Grahic Jump Location
Fig. 22

The front and back views of the modeled base plate

Grahic Jump Location
Fig. 21

The front and back views of the modeled compliant mechanism

Grahic Jump Location
Fig. 20

The stress distribution for the topology of four curved beams

Grahic Jump Location
Fig. 19

The undeformed and deformed compliant mechanisms for the topology of four curved beams

Grahic Jump Location
Fig. 18

The actual output torque curve for the topology of four curved beams

Grahic Jump Location
Fig. 17

The synthesis result for the topology of four curved beams

Grahic Jump Location
Fig. 16

The stress distribution for the topology of three curved beams

Grahic Jump Location
Fig. 15

The undeformed and deformed compliant mechanisms for the topology of three curved beams

Grahic Jump Location
Fig. 14

The actual output torque curve for the topology of three curved beams

Grahic Jump Location
Fig. 13

The synthesis result for the topology of three curved beams

Grahic Jump Location
Fig. 26

The hex tip of the screwdriver and the hex socket in the rotation shaft

Grahic Jump Location
Fig. 27

The measured output torque values of the three-beam compliant mechanism

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