Knee Joint Power Generation via Bidirectional Ball Screw
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Solution Overview
Problem
Existing knee joint power generation devices have low power generation efficiency, large weight, and high metabolic energy consumption, making them impractical for long-term use in generating power for electronic devices, especially in outdoor or military settings where natural weather conditions can hinder traditional power generation methods.
Innovation Solution
A knee joint power generation device utilizing a bidirectional ball screw drive mechanism that converts rotary motion from the knee joint into linear motion and then into rotary motion to generate electricity, featuring a lightweight and flexible design with adjustable transmission ratios to optimize power generation efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a piezoelectric shoe is used to generate electricity from human walking pressure, then the device is simple and practical, but the power generation efficiency is low
Solution Approach 1:
The patent replaces the piezoelectric mechanism with a mechanical ball screw drive system that converts knee joint motion into rotational motion of a screw shaft, which then drives a generator. This mechanical substitution achieves higher power generation efficiency while maintaining relative structural simplicity through the use of standard mechanical components.
Solution Approach 2:
The patent introduces a ball screw mechanism as an intermediary between the knee joint motion and the generator. The ball screw converts the linear reciprocating motion of the knee into rotational motion, serving as a mechanical mediator that enables efficient energy transfer to the generator while maintaining device simplicity.
2Productivity
If a backpack power generation device using cyclical changes in distance between ankle and hip joint is used, then higher power is generated, but the overall weight is large and metabolic energy consumption is high
Solution Approach 1:
The patent extracts and focuses on a specific motion parameter (knee joint motion) from the overall body movement, rather than using the entire body weight and complex multi-joint motion as in the backpack device. This extraction approach reduces the device weight while maintaining effective power generation by concentrating on the most suitable motion source.
Solution Approach 2:
The patent changes the operational parameters by using a ball screw mechanism with specific lead and pitch characteristics, and by optimizing the transmission ratio through pulley and wire rope configuration. These parameter changes enable efficient power generation from knee motion without requiring the large weight and complex structure of the backpack device.
3Productivity
If a backpack power generation device using cyclical changes in distance between ankle and hip joint is used, then higher power is generated, but metabolic energy consumption is large
Solution Approach 1:
The patent extracts and utilizes only the knee joint motion for power generation, separating this specific motion from the overall body movement. This extraction approach reduces the metabolic energy consumption compared to devices that require large body movements or weight lifting, while still achieving effective power generation from the extracted knee motion.
Solution Approach 2:
The patent replaces complex body motion capture and conversion mechanisms with a direct mechanical ball screw drive that efficiently converts knee joint motion into generator rotation. This substitution reduces energy loss in the transmission system and minimizes metabolic energy consumption by using a straightforward mechanical conversion approach.
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 device achieves high power generation efficiency with reduced metabolic energy consumption, allowing for long-term, stable power generation during various activities, including high-speed running and low-speed walking, and can be easily worn on different individuals with adjustable features for different leg sizes.
Implementation Method 1
a bidirectional ball screw drive mechanism that converts rotary motion from the knee joint into linear motion and then into rotary motion
Implementation Method 2
a generator, a coupling, a first guide rail connecting member, a second guide rail connecting member
Data Source
AI summary
The present disclosure discloses a knee joint power generation device based on bidirectional ball screw drive, and belongs to the field of biomechanical energy harvesting. The power generation device converts the rotary motion of the knee joint during human movement into a linear motion of the rope by the rope driving device, and then converts the linear motion into a rotary motion through a bidirectional ball screw to directly act on the motor, thereby converting the human biological energy into electric energy in the whole process to achieve power generation. The power generation device of the disclosure can meet the requirements of normal power generation during high-speed running and low-speed walking, has long-term high-efficiency and stable performance, can be easily worn on different people, has light overall weight and costs less loss of human walking metabolism.