0
Technical Brief

Synthesizing Constant Torque Compliant Mechanisms Using Precompressed Beams

[+] Author and Article Information
Ishit Gandhi

Department of Mechanical Engineering,
Texas A&M University-Kingsville,
Kingsville, TX 78363
e-mail: ishu9594@gmail.com

Hong Zhou

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

Contributed by the Mechanisms and Robotics Committee of ASME for publication in the JOURNAL OF MECHANICAL DESIGN. Manuscript received March 13, 2018; final manuscript received August 15, 2018; published online October 8, 2018. Assoc. Editor: Dar-Zen Chen.

J. Mech. Des 141(1), 014501 (Oct 08, 2018) (7 pages) Paper No: MD-18-1212; doi: 10.1115/1.4041330 History: Received March 13, 2018; Revised August 15, 2018

A constant torque compliant mechanism (CM) generates an output torque that keeps invariant in a large range of input rotation. Because of the constant torque feature and the merits of CMs, they are used in automobile, aerospace, medical, healthcare, timing, gardening, and other devices. A common problem in the current constant torque CMs is their preloading range that is a certain starting range of the input rotation. In the preloading range, the output torque of a constant torque CM does not have the desired constant torque. It increases from zero to a value. The preloading range usually accounts for one-third of the entire input rotation range, which severally weakens the performance of constant torque CMs. In this paper, the preloading problem is eradicated by using precompressed beams as building blocks for constant torque CMs. It is challenging to synthesize constant torque CMs composed of precompressed beams because of the integrated force, torque, and deflection characteristics. The synthesis of constant torque CMs is systemized as parameter optimization of the composed precompressed beams. The presented synthesis method is demonstrated by synthesizing constant torque CMs with different numbers of precompressed beams and validated by experimental results.

Copyright © 2019 by ASME
Your Session has timed out. Please sign back in to continue.

References

Howell, L. L. , 2001, Compliant Mechanisms, Wiley, New York.
Howell, L. L. , Magleby, S. P. , and Olsen, B. M. , 2013, Handbook of Compliant Mechanisms, Wiley, New York.
McGuire, J. R. , 1994, “ Analysis and Design of Constant-Torque Springs Used in Aerospace Applications,” Ph.D. dissertation, University of Texas in Austin, Austin, TX.
Hou, C. W. , and Lan, C. C. , 2013, “ Functional Joint Mechanisms With Constant-Torque Outputs,” Mech. Mach. Theory, 62, pp. 161–181. [CrossRef]
Norton, R. L. , 2013, Machine Design, 5th ed., Prentice Hall, Upper Saddle River, NJ.
Schmid, S. R. , Hamrock, B. J. , and Jacobson, B. O. , 2014, Fundamentals of Machine Elements, 3rd ed., CRC Press, New York.
Jutte, C. V. , and Kota, S. , 2008, “ Design of Nonlinear Springs for Prescribed Load-Displacement Functions,” ASME J. Mech. Des., 130(8), pp. 1–10. [CrossRef]
Ahmed, A. , and Zhou, H. , 2014, “ Synthesis of Nonlinear Spiral Torsion Springs,” Int. J. Eng. Res. Technol., 3(6), pp. 4–9.
Norton, R. L. , 2012, An Introduction to the Synthesis and Analysis of Mechanisms and Machines, 5th ed., McGraw-Hill, New York.
Associated Spring Corporation, 1981, Engineering Guide to Spring Design, Associated Spring Corporation, Bristol, CT.
Brown, A. A. , 1981, Mechanical Springs, Oxford University Press, Oxford, UK.
Prakashah, H. N. , and Zhou, H. , 2016, “ Synthesis of Constant Torque Compliant Mechanisms,” ASME J. Mech. Rob., 8(6), pp. 1–8.
Hao, G. , 2018, “ A Framework of Designing Compliant Mechanisms With Nonlinear Stiffness Characteristics,” Microsyst. Technol., 24(4), pp. 1795–1802. [CrossRef]
Boyle, C. , Howell, L. L. , Magleby, S. P. , and Evans, M. S. , 2003, “ Dynamic Modeling of Compliant Constant-Force Compression Mechanisms,” Mech. Mach. Theory, 38(12), pp. 1469–1487. [CrossRef]
Pedersen, C. B. W. , Fleck, N. A. , and Ananthasuresh, G. K. , 2006, “ Design of a Compliant Mechanism to Modify an Actuator Characteristic to Deliver a Constant Output Force,” ASME J. Mech. Des., 128(5), pp. 1101–1112. [CrossRef]
Chen, Y. H. , and Lan, C. C. , 2012, “ An Adjustable Constant-Force Mechanism for Adaptive End-Effector Operations,” ASME J. Mech. Des., 134(3), p. 031005. [CrossRef]
Rahman, U. M. , and Zhou, H. , 2014, “ Design of Constant Force Compliant Mechanisms,” Int. J. Eng. Res. Technol., 3(7), pp. 14–19.
Wang, J. Y. , and Lan, C. C. , 2014, “ A Constant-Force Compliant Gripper for Handling Objects of Various Sizes,” ASME J. Mech. Des., 136(7), p. 071008. [CrossRef]
Hao, G. , and Li, H. , 2016, “ Extended Static Modeling and Analysis of Compliant Compound Parallelogram Mechanisms Considering the Initial Internal Axial Force,” ASME J. Mech. Rob., 8(4), pp. 1–11. [CrossRef]
Dill, E. H. , 2012, The Finite Element Method for Mechanics of Solids With ANSYS Applications, CRC Press, New York.
Moaveni, S. , 2015, Finite Element Analysis Theory and Application With ANSYS, 4th ed., Pearson, Upper Saddle River, NJ.
Lee, H. H. , 2016, “ Finite Element Simulations With ANSYS Workbench 17,” SDC Publications, Mission, KS.
ANSYS, 2016, “ Design Modeler User's Guide,” ANSYS, Canonsburg, PA.
ANSYS, 2016, “ ANSYS Mechanical User's Guide,” ANSYS, Canonsburg, PA.
ANSYS, 2016, “ Design Exploration User's Guide,” ANSYS, Canonsburg, PA.
IMADA Incorporated, 2017, “ KTC Digital Torque Screwdriver Instruction Manual,” IMADA Incorporated, Northbrook, IL.

Figures

Grahic Jump Location
Fig. 1

The undeformed beam

Grahic Jump Location
Fig. 3

The solid model of a straight undeformed beam

Grahic Jump Location
Fig. 4

The deformed shape of the pined–pined beam and its stress distribution

Grahic Jump Location
Fig. 5

The deformed shape of the fixed–fixed beam and its stress distribution

Grahic Jump Location
Fig. 6

The deformed shape of the 10–20 deg beam and its stress distribution

Grahic Jump Location
Fig. 7

An annular design domain for a three-beam CTCM

Grahic Jump Location
Fig. 8

An annular design domain for a two-beam CTCM

Grahic Jump Location
Fig. 9

The Tθ relationship curve

Grahic Jump Location
Fig. 10

The solid model of the three-beam CTCM

Grahic Jump Location
Fig. 11

The meshed model of the three-beam CTCM

Grahic Jump Location
Fig. 12

The synthesized three-beam CTCM with input rotation angle of 0 deg

Grahic Jump Location
Fig. 13

The synthesized three-beam CTCM with input rotation angle of 60 deg

Grahic Jump Location
Fig. 14

The solid model of the two-beam CTCM

Grahic Jump Location
Fig. 15

The synthesized two-beam CTCM with input rotation angle of 0 deg

Grahic Jump Location
Fig. 16

The synthesized two-beam CTCM with input rotation angle of 60 deg

Grahic Jump Location
Fig. 17

The prototype of the synthesized three-beam CTCM

Grahic Jump Location
Fig. 18

The output torque measurement of the synthesized three-beam CTCM

Grahic Jump Location
Fig. 19

The measured and analyzed output torque values of the three-beam CTCM

Grahic Jump Location
Fig. 20

The prototype of the synthesized two-beam CTCM

Grahic Jump Location
Fig. 21

The output torque measurement of the synthesized two-beam CTCM

Grahic Jump Location
Fig. 22

The measured and analyzed output torque values of the two-beam CTCM

Tables

Errata

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