Additively Manufactured Magnetic Materials with Patterned Air Pockets

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Solution Overview

Problem

Conventional magnetic cores and permanent magnets face challenges in reducing eddy current loss, particularly in additively manufactured materials, where laminating with insulation layers is difficult due to high-temperature heat treatment requirements and complex structural designs.

Innovation Solution

The introduction of patterned air pockets within the magnetic materials, designed to increase the eddy current path length and reduce the cross-sectional area of the magnetic flux loop, achieved through additive manufacturing, which guides eddy currents and shapes magnetic flux without compromising magnetic permeability or saturation flux density.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If laminated structures with insulating layers are used to reduce eddy current loss, then eddy current loss is reduced, but manufacturing complexity increases due to the need for thin insulation layer deposition and high-temperature heat treatment compatibility

Engineering Contradiction:

Improveeddy current lossVSAvoidmanufacturing complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The patent introduces air pockets (porous structures) within the magnetic material body to disrupt eddy current paths. These air pockets act as natural insulators without requiring additional insulating layers, thereby reducing eddy current loss while avoiding the manufacturing complexity associated with lamination and insulation layer deposition.

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The magnetic material is segmented into multiple regions by introducing air pockets at different positions and orientations. This segmentation divides the continuous magnetic flux path into discrete sections, effectively reducing eddy current loops without requiring complex laminated structures or insulating layers.

Inventive Principle:

Principle #1Segmentation

2Ease of manufacture

If conventional solid block additive manufacturing is used, then manufacturing simplicity is maintained, but eddy current loss remains high due to continuous magnetic flux paths

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoideddy current loss

Core Design Contradiction:

Ease of manufactureVSLoss of energy

Solution Approach 1:

The patent incorporates air pockets (porous structures) within the additively manufactured magnetic material to disrupt continuous magnetic flux paths. This maintains the manufacturing simplicity of additive manufacturing while effectively reducing eddy current loss by breaking up the continuous conductive paths present in solid block structures.

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The patent creates a composite structure by combining magnetic material with air pockets (non-magnetic regions). This composite approach allows the magnetic material to retain its beneficial properties while the air pockets provide eddy current disruption, achieving low energy loss without compromising manufacturing simplicity.

Inventive Principle:

Principle #40Composite materials

3Loss of energy

If air pockets are introduced to reduce eddy current loss, then eddy current path length increases and loss decreases, but magnetic permeability and saturation flux density may be compromised

Engineering Contradiction:

Improveeddy current lossVSAvoidmagnetic permeability

Core Design Contradiction:

Loss of energyVSUse of energy by moving object

Solution Approach 1:

The patent strategically positions air pockets at specific locations within the magnetic material where they most effectively disrupt eddy current paths without significantly impacting the overall magnetic flux density. This local quality approach ensures that air pockets reduce eddy current loss while minimizing their negative impact on magnetic permeability and saturation flux density.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses a controlled density and distribution of air pockets that provides sufficient eddy current disruption without excessive removal of magnetic material. This partial action approach maintains adequate magnetic permeability and saturation flux density while achieving effective eddy current loss reduction.

Inventive Principle:

Principle #16Partial or excessive action

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 approach effectively reduces eddy current loss by increasing the path length of eddy currents and optimizing magnetic permeability, allowing for tailored flux patterns and improved performance in electric machine stators and rotors.

Implementation Method 1

magnetic materials having three-dimensional structures to reduce eddy current loss

Methodology Applied

Scientific EffectEddy currents: Eddy Currents

Implementation Method 2

optimizing magnetic permeability, allowing for tailored flux patterns

Methodology Applied

Scientific EffectMagnetic permeability: Magnetic Field

Data Source

PatentUS11682932B2Additively manufactured magnetic materials with structural designs

Publication Date: 2023.06.20 FORD GLOBAL TECH LLC

AI summary

An electric machine stator includes a soft magnetic yoke having a cylindrical yoke body extending along a central axis, with an outer surface and an inner periphery defining a central opening about the central axis, and a plurality of soft magnetic stator teeth. Each stator tooth defines a first set of air pockets, and a second set of air pockets. An electric machine rotor and permanent magnet material with air pockets are also provided.