Upper Arm Module Link Mechanism for Wearable Strength Assist
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Solution Overview
Problem
Conventional wearable muscular strength assisting apparatuses face issues with durability, assemblability, and noise due to the combination of cams and wires, which cause friction and sliding problems.
Innovation Solution
The upper arm module uses a configuration of links and an elastic body without wires or cams, allowing for a torque profile that varies rotational torque based on the angle of the upper arm, improving durability and assemblability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a torque profile is formed by combining a cam and a wire, then the gravitational load can be compensated within a limited operating range, but durability deteriorates and noise problems occur due to friction and sliding between components
Solution Approach 1:
The patent replaces the cam-and-wire mechanical system with a link-based parallel mechanism. Specifically, it uses multiple links (first link, second link, third link) connected through rotational joints to form a four-bar linkage system that generates the torque profile without sliding contacts. This substitution eliminates friction and sliding between components while maintaining the gravity compensation function.
Solution Approach 2:
The patent divides the torque generation function into multiple separate links (first link, second link, third link) rather than using a single cam mechanism. Each link is responsible for a portion of the motion transmission, and their coordinated movement through rotational joints produces the desired torque profile. This segmentation distributes the mechanical stress and eliminates concentrated friction points.
2Ease of manufacture
If a torque profile is formed by combining a cam and a wire, then the gravitational load can be compensated, but assemblability deteriorates
Solution Approach 1:
The patent replaces the complex cam-and-wire assembly with a simpler link-based parallel mechanism. The new design uses standard rotational joints and straight links that are easier to manufacture and assemble. The elastic body (spring) is directly integrated with the links through simple coupling points, eliminating the need for separate cam profiles and wire routing.
3Reliability
If links are used to form a torque profile without wires, then durability and assemblability are improved, but the device complexity changes
Solution Approach 1:
The patent merges the torque profile generation function with the structural support function of the links. The same links that provide structural stability also generate the torque profile through their geometric configuration and movement. The elastic body is integrated into the link system rather than being a separate component, reducing overall system complexity while maintaining durability.
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 configuration enhances durability and assemblability while providing a torque profile that effectively supports the wearer's upper arm, compensating for gravity and improving muscle strength assistance.
Implementation Method 1
an elastic body being configured such that a first end thereof is coupled to the upper arm part at a position spaced apart from the first end of the upper aim part in an extension direction of the upper arm part, and a second end thereof is coupled to the second link at a third point spaced apart from the first point and the second point of the second link, and generating an elastic force by deformation
Implementation Method 2
a first link configured such that a first end thereof is rotatably coupled to the base part at a point of application spaced apart from the fixed point; a second link extending on a plane on which the upper aim part extends, and being rotatably coupled to a second end of the first link at a first point; a third link coupled to the second link at a second point spaced apart from the first point of the second link to guide movement of the second point
Data Source
AI summary
An upper arm module of a wearable muscular strength assisting apparatus includes: a base part fixedly connected to a wearer's body; an upper arm part being configured such that a first end thereof is coupled to the base part to be rotatable about a fixed point, and being coupled to the wearer's upper arm to apply a rotational torque thereto; a first link configured such that a first end thereof is rotatably coupled to the base part at a point of application; a second link extending on a plane on which the upper arm part extends, and being rotatably coupled to a second end of the first link at a first point; a third link coupled to the second link at a second point to guide movement of the second point; and an elastic body generating an elastic force by deformation.