Actuator Leaf Spring with Localized Support for Prosthesis Downsizing
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Solution Overview
Problem
Existing prosthetic devices using series elastic actuators with leaf springs face challenges in downsizing while maintaining mechanical strength and measurement accuracy under varying torque loads.
Innovation Solution
The proposed actuator design incorporates a leaf spring with a U-shaped bent portion and extending portions that are cantilevered, supported by a support member when torque exceeds a predetermined value, allowing for deformation in the plate thickness direction and preventing plastic deformation by utilizing a deformation guide to manage bending moments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the leaf spring is designed to be flexible and deformable for torque transmission, then the actuator can be downsized, but the risk of plastic deformation increases under high torque loads
Solution Approach 1:
The patent changes the structural parameters of the leaf spring by introducing a support member that provides additional support at specific locations. This modifies the bending moment distribution along the leaf spring, allowing the spring to remain flexible for downsizing while preventing plastic deformation under high torque loads through optimized structural parameters.
Solution Approach 2:
The support member acts as an intermediary element between the leaf spring and the housing. It provides localized support to the leaf spring, reducing the bending moment at critical points and preventing plastic deformation while allowing the leaf spring to maintain its flexibility for torque transmission and actuator downsizing.
2Reliability
If the leaf spring is supported at multiple points to prevent plastic deformation, then reliability improves, but the device complexity increases
Solution Approach 1:
Instead of providing uniform support along the entire leaf spring, the patent applies support at specific localized positions where the bending moment is highest. This local quality approach prevents plastic deformation at critical points while minimizing the number of support members needed, thereby maintaining reliability without significantly increasing device complexity.
3Measurement precision
If the leaf spring is made stiffer to transmit torque accurately, then measurement precision improves, but the actuator cannot be downsized
Solution Approach 1:
The patent segments the leaf spring support function by introducing discrete support members at specific locations rather than making the entire leaf spring stiffer. This segmentation allows the leaf spring to remain flexible and compact for downsizing while the support members provide the necessary stiffness at critical points to ensure accurate torque transmission and measurement.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design enables the downsizing of prosthetic devices while maintaining high rigidity and preventing plastic deformation, ensuring accurate torque transmission and measurement under both low and high torque conditions.
Implementation Method 1
the extending portion being bendable and deformable in a plate thickness direction according to torque by transmitting the torque
Implementation Method 2
preventing plastic deformation by utilizing a deformation guide to manage bending moments
Data Source
AI summary
The present disclosure relates to an actuator and a prosthesis that can propose an actuator and a prosthesis that can downsize a device.An actuator includes: a leaf spring that includes a bent portion bent in a U shape and a first extending portion extending from the bent portion, a first one end portion that is an end portion of the first extending portion on a side of the bent portion being cantilevered, the first extending portion being bendable and deformable in a plate thickness direction according to torque by transmitting the torque; and a first support member that supports a part of the first extending portion on a bending direction side in a case where torque transmitted in a first direction by the first extending portion is larger than a predetermined value. The present technology can be applied to, for example, a prosthesis.