Design and Optimization of a Large-Stroke Compliant Constant-Torque Mechanism

Authors

  • Thanh Vu Phan Ho Chi Minh City University of Technology and Education, Vietnam
  • Huy-Tuan Pham Ho Chi Minh City University of Technology and Education, Vietnam

Corressponding author's email:

phtuan@hcmute.edu.vn

DOI:

https://doi.org/10.54644/jte.68.2022.1098

Keywords:

constant-torque mechanism, compliant mechanism, genetic algorithm, finite element analysis, rotary mechanism

Abstract

Compliant constant-torque mechanism (CTM) can produce an output torque that does not change within a prescribed input rotation range. This stability is maintained regardless of complicated sensorized control systems. Owing to the monolithic nature of the compliant mechanism, the device is more compact, lightweight, and portable, which is favorable to human joint rehabilitative devices or mobility-assisting devices. However, before approaching the stable range, the mechanism has to undergo a pre-loading range which usually accounts for one-third of the entire operational journey. In addition, the deformation of flexible segments is restricted due to the yield strength of the materials. This limited working range hampers other potential applications of compliant CTMs. This paper presents a novel design of a compliant 2-stage CTM with long-stroke by using serially connected curved beams that deform sequentially. The design process is implemented via a shape optimization scheme using genetic algorithm. Finite element analysis is used to characterize the constant-torque behavior of the CTM under static loading. A general design formulation is also proposed to synthesize this special kind of compliant mechanism. The results show that this CTM gets the stable torque range from 300 to 1100 over two stages with the deviation less than 4.3%.

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Author Biographies

Thanh Vu Phan, Ho Chi Minh City University of Technology and Education, Vietnam

 Thanh-Vu Phan received the M.S. degree in mechanical engineering from Ho Chi Minh City University of Technology and Education, Vietnam, in 2012. He is currently pursuing the Ph.D. degree in mechanical engineering at Ho Chi Minh City University of Technology and Education, Vietnam. His research interest includes compliant mechanisms and advanced manufacturing

Huy-Tuan Pham, Ho Chi Minh City University of Technology and Education, Vietnam

Huy-Tuan Pham received the Ph.D. degree in precision engineering from National Chung Hsing University, Taiwan in 2011. He is currently an Associate Professor at Ho Chi Minh City University of Technology and Education, Vietnam. His research interest includes compliant mechanisms and their applications, ultrasonics and vibration-assisted machining methods.

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Published

28-02-2022

How to Cite

[1]
T. V. Phan and H.-T. Pham, “Design and Optimization of a Large-Stroke Compliant Constant-Torque Mechanism”, JTE, vol. 17, no. 1, pp. 93–100, Feb. 2022.