High-Torque-Capacity Helical Flexures for Series Elastic Actuators
Journal
IEEE/ASME Transactions on Mechatronics
ISSN
10834435
Date Issued
2025
Author(s)
Huang, Chunhung
Abstract
Series elastic actuators (SEAs) achieve output torque and stiffness control by managing the deformation of a spring arranged between the motor and the output. SEAs are ideal for tasks involving human-robot interaction and unstructured environments. The stiffness, size, and torque capacity of the spring are crucial for the performance of an SEA. To increase the torque capacity of an SEA while maintaining a compact size, this article proposes a novel helical flexure as the spring in an SEA. The helical flexure is formed on the thin wall of a tube to generate high torque output with minimal reaction forces and moments. The resulting compliant tube can be combined with other transmission components to reduce the number of components and allow the inner passage of cables and shafts. Simulation comparisons and experimental testing verify the merits of the proposed helical flexure. An SEA prototype is fabricated to demonstrate the performance of the new helical flexure during zero-torque and high-torque motion. It is expected that this new helical flexure will offer a competitive solution for designing compact springs used in various SEAs.
Subjects
Back-drivability
Helical Flexure
Maximum Equivalent Stress
Pure Torque Transmission
Series Elastic Actuator (sea)
Torque Capacity
Bending (deformation)
Elastic Deformation
Back-drivability
Equivalent Stress
Helical Flexure
High Torque
Maximum Equivalent Stress
Pure Torque Transmission
Series Elastic Actuator
Series Elastic Actuators
Torque Capacity
Torque Transmission
Helical Springs
Publisher
Institute of Electrical and Electronics Engineers Inc.
Type
journal article