Shape Memory Alloy Diaphragm Valve Without Solenoid Complexity

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Solution Overview

Problem

Variable flow valves relying on solenoid elements face operational drawbacks such as complexity in electronics, susceptibility to electromagnetic interference, and degradation due to dust and moisture infiltration.

Innovation Solution

A variable flow control valve utilizing a shape memory alloy wire that changes length in response to temperature, coupled with a diaphragm biased by an elastic element, allowing for fluid flow control without complex electronics, and is resistant to electromagnetic interference and contamination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If solenoid elements are used to control the diaphragm, then the valve can achieve reliable fluid flow control, but the device complexity increases due to required electronics and susceptibility to electromagnetic interference

Engineering Contradiction:

Improvefluid flow control reliabilityVSAvoidelectronics complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the solenoid-based electromagnetic actuation system with a shape memory alloy wire that directly actuates the diaphragm through thermal contraction. This substitution eliminates complex electronics, electromagnetic interference susceptibility, and dust/moisture infiltration issues while maintaining reliable fluid flow control between open and closed positions.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the actuation mechanism from electromagnetic field-based (solenoid) to thermal-based (shape memory alloy). By applying electrical current to heat the shape memory alloy wire, it contracts and pulls the diaphragm to the closed position. When heated, the wire contracts; when cooled, it returns to its original length, enabling the diaphragm to return to the open position.

Inventive Principle:

Principle #35Parameter changes

2Ease of operation

If solenoid elements are used to operate the valve, then the valve can be controlled, but it becomes susceptible to dust and moisture infiltration that degrades performance

Engineering Contradiction:

Improvevalve control capabilityVSAvoiddust and moisture infiltration

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Force

If a shape memory alloy wire is used to pull the diaphragm, then the wire must generate sufficient force to overcome the bias, but this requires significant contraction force from the wire

Engineering Contradiction:

Improvediaphragm actuation forceVSAvoidwire contraction force requirement

Core Design Contradiction:

ForceVSStrength

Solution Approach 1:

The patent employs a pulley system with mechanical advantage to amplify the force generated by the shape memory alloy wire. The wire is routed through pulleys that provide mechanical leverage, allowing a relatively weak shape memory alloy wire to generate sufficient force to overcome the elastic element's bias and actuate the diaphragm against the biasing force.

Inventive Principle:

Principle #15Dynamics

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 valve provides a lightweight, quiet, and reliable fluid flow control solution that is easy to manufacture and suitable for various applications, including aircraft and medical uses, with reduced susceptibility to electromagnetic interference and contamination.

Implementation Method 1

The wire includes shape memory alloy and has an uncontracted length in an unheated state whereby the wire permits assumption of the first condition by the diaphragm due to the bias and a contracted length in a heated state whereby the wire pulls the diaphragm toward assumption of the second condition

Methodology Applied

Scientific EffectShape memory alloy: Shape Memory Alloy

Implementation Method 2

an elastic element is configured to apply the bias to the diaphragm or the diaphragm has an elastic characteristic from which the bias arises

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS10982783B2Variable flow controlled diaphragm valve based on shape memory alloy

Publication Date: 2021.04.20 HAMILTON SUNDSTRAND CORP

AI summary

A valve is provided and includes a valve body defining a pathway, a diaphragm and a wire. The diaphragm is configured to assume first or second conditions in which the diaphragm blocks or permits fluid flow through the pathway, respectively. The diaphragm is biased toward assumption of the first condition. The wire is coupled to the diaphragm. The wire has an uncontracted length in an unheated state whereby the wire permits assumption of the first condition by the diaphragm due to the bias and a contracted length in a heated state whereby the wire pulls the diaphragm toward assumption of the second condition in opposition to the bias.