Dual-Metal Rotor Gradient Structure for Thermal Stress Resistance

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Solution Overview

Problem

Traditional rotors in machines, such as aircraft compressors, face challenges with high temperature and stress resistance due to their single metal composition, leading to potential failure and increased downtime.

Innovation Solution

A rotor formed with a hub and blades made of at least two metals with different thermal expansion coefficients, combined in layers with an intermediate gradient, and potentially incorporating a shape memory alloy, to enhance resistance to temperature and speed-induced forces through controlled expansion and deformation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a rotor is formed of a single metal, then the manufacturing process is simple, but the rotor is less resistant to forces experienced at high temperature and speed

Engineering Contradiction:
Improveresistance to forcesVSAvoidmetal composition
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The rotor is constructed using composite materials comprising at least two distinct metals with different thermal expansion coefficients. This composite structure allows the rotor to better withstand thermal and mechanical forces experienced during high-speed operation, directly resolving the contradiction between reliability and material complexity by using multi-metal composition.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies local quality by creating regions with different metal compositions in specific areas of the rotor. The gradient structure transitions from one metal composition to another, allowing different parts of the rotor to have optimized properties for their specific functional requirements, thereby improving overall resistance to forces while managing complexity through localized material variation.

Inventive Principle:
Principle #3Local quality

2Stress or pressure

If a rotor is formed of a single metal, then the manufacturing process is straightforward, but the rotor experiences high stress and strain at elevated temperatures

Engineering Contradiction:
Improvestress resistanceVSAvoidmanufacturing process
Core Design Contradiction:
Stress or pressureVSEase of manufacture

Solution Approach 1:

The dual-metal composite construction reduces stress and strain at elevated temperatures by utilizing metals with complementary properties. The different thermal expansion coefficients of the constituent metals allow for stress distribution and compensation, improving stress resistance while maintaining manufacturability through established additive manufacturing processes.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes material parameters by selecting metals with specific thermal expansion coefficients and mechanical properties. This parameter optimization allows the rotor to better handle thermal stress and mechanical loads, resolving the contradiction between stress resistance and ease of manufacture by carefully selecting and combining materials with appropriate properties.

Inventive Principle:
Principle #35Parameter changes

3Strength

If a rotor is formed of a single metal, then the structure is simple, but the rotor has lower stiffness at high speeds

Engineering Contradiction:
ImprovestiffnessVSAvoidmaterial structure
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The composite material structure increases rotor stiffness by combining metals with different mechanical properties. The interaction between the two metals creates a structure that is stiffer and more resistant to deformation at high speeds, while the additive manufacturing process maintains reasonable structural complexity through controlled material deposition.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The gradient structure provides local quality optimization by varying material composition to achieve desired stiffness characteristics in different rotor regions. This allows the rotor to have enhanced stiffness where needed while maintaining overall structural integrity, resolving the contradiction between strength and device complexity through spatially varying material properties.

Inventive Principle:
Principle #3Local quality

4Reliability

If a rotor is formed of a single metal, then thermal expansion is uniform, but the rotor is more susceptible to failure under thermal stress

Engineering Contradiction:
Improvefailure resistanceVSAvoidmaterial composition
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The dual-metal composite structure improves failure resistance by utilizing the different thermal expansion coefficients of the constituent metals. This creates a structure that can better accommodate thermal stress through differential expansion, reducing the likelihood of thermal failure while maintaining compositional stability through the gradient transition between metals.

Inventive Principle:
Principle #40Composite materials

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 dual-metal rotor design reduces stress and strain, increases stiffness, and minimizes failure rates, resulting in improved performance, reduced downtime, and increased compression efficiency by managing thermal expansion and mechanical stresses effectively.

Implementation Method 1

The two metal materials are selected to have different thermal expansion coefficients such that the overall rotor will be more resistant to forces it may experience as temperature or speed increases

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

In another embodiment a shape memory alloy is used to provide the resistance

Methodology Applied
Scientific EffectShape memory alloy effect: Shape Memory Alloy

Data Source

PatentEP4209681A1Rotor formed of multiple metals
Publication Date: 2023.07.12 HAMILTON SUNDSTRAND CORP
  • EP4209681A1 patent drawingFigure 1
  • EP4209681A1 patent drawingFigure 2
  • EP4209681A1 patent drawingFigure 3A

AI summary

A rotor (26) for a machine under this disclosure could be said to include a hub (100) having a plurality of blades extending radially outwardly of the hub (100). At least one of the hub (100) and the plurality of blades is formed of at least two metal materials. The two metal materials (102, 104) are selected to have different thermal expansion coefficients such that the overall rotor will be more resistant to forces it may experience as temperature or speed increases. There are layers of each of the two metal materials (102, 104), with an intermediate gradient wherein the two materials (102, 104) are mixed. Alternatively, a shape memory alloy may be used. A method is also disclosed.