Shape-Memory Coil Spring Generator for Continuous Power Output

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Solution Overview

Problem

Existing power generation devices using shape memory alloy springs face instability due to temperature-dependent deformation, leading to unstable and non-continuous power generation, and are prone to distortion, which reduces their effectiveness and shortens their lifespan.

Innovation Solution

A power generation device utilizing two coil springs made of shape memory alloy, one heated above a threshold temperature and the other cooled below it, within a sealed tank partitioned into two temperature-controlled spaces, enabling continuous reciprocating motion to drive a generator through a rotation transmission mechanism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single shape memory alloy spring is used for power generation, then the device structure is simple, but the power generation cannot be continuous and stable

Engineering Contradiction:
Improvestructure simplicityVSAvoidpower generation stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent divides the power generation system into multiple independent shape memory alloy springs (at least two springs) that operate in sequence. Each spring undergoes expansion and contraction cycles independently, ensuring that when one spring is in its austenite phase (expanded state), another is in its martensite phase (contracted state), thereby maintaining continuous reciprocating motion and stable power generation output.

Inventive Principle:
Principle #1Segmentation

2Power

If the shape memory alloy spring is stretched excessively to increase power output, then the power generation capacity increases, but the spring distortion occurs and lifespan shortens

Engineering Contradiction:
Improvepower generation capacityVSAvoidspring lifespan
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The patent incorporates guide grooves or guide structures that constrain the shape memory alloy springs to move along predetermined paths during expansion and contraction. This preventive guidance system stops the springs from deflecting or distorting before excessive deformation can occur, thereby protecting the springs from damage while maintaining effective power generation capacity.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Productivity

If the shape memory alloy spring is made longer to increase displacement, then the power generation efficiency improves, but the spring deflection increases

Engineering Contradiction:
Improvepower generation efficiencyVSAvoidspring deflection
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The patent introduces guide grooves or support structures that preemptively prevent lateral deflection of the springs during operation. These guide structures ensure that even longer springs maintain their axial alignment throughout the expansion and contraction cycles, allowing increased displacement for higher efficiency without suffering from deflection-related instability.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

4Device complexity

If external temperature control is used for the shape memory alloy spring, then the device structure is simple, but the temperature control is unstable and power generation is intermittent

Engineering Contradiction:
Improvetemperature control structureVSAvoidtemperature control stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent employs self-heating capabilities through resistive heating elements integrated with or adjacent to the shape memory alloy springs. The springs can autonomously generate the necessary heat to transform from martensite to austenite phase by passing current through them, eliminating dependence on unstable external temperature sources and ensuring reliable, on-demand phase transformation for continuous power generation.

Inventive Principle:
Principle #25Self-service

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 stable and continuous power generation by alternating the expansion and contraction of the coil springs, maintaining precise temperature control to prevent distortion and extend the lifespan of the springs.

Implementation Method 1

a first coil spring made of a shape memory alloy, one end being fixed to the inner wall of the sealed tank, and the other being connected to the first partition wall, wherein the spring extends and deforms when heated above a predetermined threshold temperature and weakens when cooled below said threshold temperature

Methodology Applied
Scientific EffectShape memory alloy effect: Shape Memory Alloy

Implementation Method 2

a rotation transmission mechanism that links the reciprocating means to a rotating shaft and converts the reciprocating movement of the reciprocating means into unidirectional rotation of the rotating shaft

Methodology Applied
Scientific EffectMechanical conversion through gear mechanism: Gear

Implementation Method 3

Power generation device capable of generating electricity by driving the rotating shaft of a generator

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4663945A1Power generation device
Publication Date: 2025.12.17 TAIRA TOKUHIRO
  • EP4663945A1 patent drawingFigure 1
  • EP4663945A1 patent drawingFigure 2
  • EP4663945A1 patent drawingFigure 3(a)~3(b)

AI summary

This invention generates power stably and continuously by expansion/contraction deformation of a coil spring formed from a shape-memory alloy.In this power generation device, a first partition wall 4 is provided in a sealed tank 1 so as to be capable of reciprocating. In the sealed tank 1, a first coil spring 2 and a second coil spring 3 are provided with the first partition wall 4 therebetween. Each of the coil springs 2 and 3 expansion-deforms when heated to a temperature equal to or higher than a threshold temperature T, and weakens when cooled to a temperature lower than the threshold temperature T. A looped belt 16 is connected to the first partition wall 4, and a rotary transmission mechanism 17 provided on a rotor rotation shaft 23 of a generator 20 is linked to the looped belt 16. The reciprocal movement of the looped belt 16 generated by alternately performing the expansion deformation and weakening of the first coil spring 2 and the second coil spring 3 is converted into rotation of the rotation shaft 23 in one direction by means of the rotary transmission mechanism 17, whereby continuous power generation by the generator 20 is performed.