Rotary Power Generation Mechanism Preventing Spring Winding
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Solution Overview
Problem
Rotary power generation devices using electrets face issues where the spiral spring can become wound up or fully extended, limiting the rotary motion of the electrode and restricting the generation of electric power from vibrations of various periods.
Innovation Solution
The design includes a first and second rotary member with different moments of inertia, an elastic member connecting them, and an electret film on one of the members, preventing spiral spring winding and allowing efficient power generation from various vibration frequencies by ensuring the electret film is formed on the second rotary member and an additional stationary member is opposed to it.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the electrode is supported while being connected to the rotary weight, spiral spring, and stationary member in sequence, then the power generation mechanism can be compact, but the spiral spring may be wound up or fully extended depending on attitude change
Solution Approach 1:
The power generation mechanism is divided into two independent rotational systems: the first rotary member (rotary weight) connected to the spiral spring and stationary member, and the second rotary member (electrode) that rotates independently. This segmentation prevents the spiral spring from being wound up or fully extended by the electrode's rotation, while maintaining compact dimensions.
Solution Approach 2:
The first rotary member acts as an intermediary between the spiral spring mechanism and the second rotary member (electrode). It transmits rotational motion to the electrode through elastic connection without directly coupling the electrode to the spiral spring, thereby preventing the spring from becoming fully extended or wound up.
2Device complexity
If the natural angular frequency of the rotary motion is uniquely determined by the spring constant and mass, then the system is simple, but it cannot efficiently generate electric power from vibrations of various periods
Solution Approach 1:
The system transitions from a fixed frequency system to a dynamic frequency system by introducing a second rotary member with different moment of inertia. The two rotary members can rotate at different frequencies, allowing the system to adapt to vibrations of various periods and improve power generation efficiency across different frequency conditions.
Solution Approach 2:
The moment of inertia parameter is changed by introducing a second rotary member with a different moment of inertia than the first rotary member. This parameter change enables the system to respond to a broader range of vibration frequencies, improving productivity without significantly increasing complexity.
3Device complexity
If the spiral spring is used to connect the electrode to the stationary member, then the structure is simple, but the electrode cannot perform rotary motion when the spring is fully extended
Solution Approach 1:
The connection structure is segmented into two independent rotational paths: the spiral spring connects the first rotary member to the stationary member, while the second rotary member rotates independently. This segmentation ensures that the electrode (second rotary member) can perform rotary motion without being constrained by the spiral spring's extension state.
Solution Approach 2:
The first rotary member serves as an intermediary that decouples the spiral spring's rotational constraint from the electrode's rotational motion. The elastic connection between the first and second rotary members allows the electrode to rotate freely without the spiral spring becoming fully extended or preventing motion.
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 prevents spiral spring overextension, increases power generation efficiency by matching vibration and rotational frequencies, enhances sensitivity to vibrations, and allows electric power generation regardless of vibration direction, while maintaining a compact structure.
Implementation Method 1
a first rotary member (10), which is supported in a freely rotatable manner and has a center of gravity shifted from a rotation center
Implementation Method 2
an elastic member (11) that elastically connects the first rotary member (10) and the second rotary member (12) to each other for rotary motions
Implementation Method 3
an electret film (14) that is formed on a surface of any one of the second rotary member (12) and the stationary member (13)
Data Source
Figure 1
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AI summary
Provided is an electronic device including a rotary power generation device using an electret, which is capable of preventing a spiral spring from being wound up or fully extended. The electronic device includes a power generation mechanism (6) including: first rotary member, which is supported in a freely rotatable manner, and has a center of gravity shifted from a rotation center; second rotary member supported in a freely rotatable manner; an elastic member configured to elastically connect the first rotary member and the second rotary member to each other for rotary motions thereof; a stationary member arranged so as to be opposed to the second rotary member; and an electret film formed on a surface of any one of the second rotary member and the stationary member.