Nested Link Assembly for Compact 2-DOF Motion Assistance
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Solution Overview
Problem
Existing motion assistance technologies face challenges in providing a compact and efficient mechanism for transmitting power to support multiple degrees of freedom in joint movements, particularly for elderly and patients with mobility issues, as they often require complex structures that limit the range of motion and increase bulkiness.
Innovation Solution
A link assembly comprising a main frame, base link, input link, and output link configured for at least 2-degree of freedom rotation, with a center of rotation inside the main frame, and a rotary frame to support the output link, enabling compact and versatile power transmission for rotational and translational motions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a complex structure is used to support multiple degrees of freedom in joint movements, then the range of motion is improved, but the device becomes bulkier and less compact
Solution Approach 1:
The output link is positioned inside the main frame, with its center of rotation located within the main frame boundaries. This nesting arrangement allows the mechanism to achieve 2-DOF rotation capability while maintaining a compact overall structure, as the moving components are contained within the main frame volume rather than extending outward.
Solution Approach 2:
The patent achieves 2-DOF rotation through a clever spatial arrangement where the output link rotates about an axis that passes through the main frame, and the base link and input link rotate about axes that intersect at the output link's center of rotation. This three-dimensional configuration enables multiple degrees of freedom without increasing the two-dimensional footprint or overall device volume.
2Volume of moving object
If a compact mechanism is used to minimize bulkiness, then the device size is reduced, but the power transmission efficiency for multiple degrees of freedom may be compromised
Solution Approach 1:
By nesting the output link inside the main frame and positioning its center of rotation within the main frame, the patent achieves compact dimensions while maintaining effective power transmission paths. The close proximity of the rotating components reduces transmission losses and enables efficient power transfer for 2-DOF motion.
Solution Approach 2:
The patent combines the rotation axes of the base link and input link to intersect at the output link's center of rotation, creating a unified power transmission hub. This merging of rotational centers allows multiple power transmission paths to converge efficiently within the compact main frame structure.
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
The solution allows for a compact and efficient power transmission mechanism that supports a wide range of motion while minimizing bulkiness, enhancing the usability and effectiveness of motion assistance devices for various joints, such as the talocrural, knee, hip, wrist, or elbow joints.
Implementation Method 1
The output link includes an output head connected to an interior of the main frame in a ball joint
Data Source
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AI summary
A link assembly includes a main frame, a base link rotatably connected to the main frame, an input link rotatably connected to the main frame, and an output link at least 2-degree of freedom (DOF) rotatably connected to the main frame.