Composite Magnet Restraint Curing Without Rotor Demagnetization

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Solution Overview

Problem

Existing methods for producing restraints for permanent magnet devices in electric machines face challenges such as high production costs, long production times, and the risk of demagnetization due to high temperatures during curing, which complicates achieving a sufficient safety margin between operating and curing temperatures.

Innovation Solution

The method involves arranging a mechanical restraining device made of composite material around the permanent magnet device, and using a magnetic shunt or applying a specific magnetic field to control the magnetic field of the permanent magnet device during thermal treatment, thereby preventing demagnetization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the curing temperature of the composite material is increased to improve thermal stability, then the glass transition temperature increases providing higher thermal stability, but the permanent magnet devices may be permanently de-magnetized since de-magnetization begins above the Curie temperature

Engineering Contradiction:

Improvecuring temperatureVSAvoidmagnetic stability

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

A magnetic shunt made of soft magnetic material is introduced as an intermediary component between the permanent magnet and the high-temperature environment. This shunt redirects magnetic flux paths and shields the permanent magnet from demagnetizing effects during thermal treatment, enabling curing temperatures above the permanent magnet's Curie point without permanent damage

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention changes the magnetic field parameters during thermal treatment by introducing the magnetic shunt, which modifies the magnetic flux distribution. This allows the system to withstand higher temperatures temporarily during curing while maintaining the permanent magnet's magnetic properties through controlled magnetic field management

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If the restraint is produced separately and then attached to the rotor, then the fiber composite material can be wound and cured with proper control, but the production costs are high and production times are long

Engineering Contradiction:

Improvecuring controlVSAvoidproduction time

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The production process merges two previously separate operations: the restraint is now produced directly on the rotor in-situ rather than being manufactured separately and attached later. This integration eliminates the attachment step and reduces production time while maintaining curing quality through the magnetic shunt protection

Inventive Principle:

Principle #5Merging (Combining)

3Productivity

If the restraint is produced directly on the rotor in-situ, then production costs and time are reduced, but the permanent magnet devices may be de-magnetized due to high temperatures during curing

Engineering Contradiction:

Improveproduction efficiencyVSAvoidmagnetic stability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The magnetic shunt serves as a protective intermediary during in-situ production, enabling the restraint to be cured directly on the rotor at high temperatures without demagnetizing the permanent magnets. This makes in-situ production viable by resolving the thermal protection issue

Inventive Principle:

Principle #24Intermediary (Mediator)

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 allows for higher curing temperatures without demagnetizing the permanent magnet devices, thereby reducing production costs and time while maintaining the mechanical stability of the restraints.

Implementation Method 1

using a magnetic shunt or applying a specific magnetic field to control the magnetic field of the permanent magnet device during thermal treatment, thereby preventing demagnetization

Methodology Applied

Scientific EffectMagnetic field control: Magnetic Field

Implementation Method 2

During at least a thermal treatment of the component, a way (e.g., means; a device) for targeted control of the magnetic field of the permanent magnet device is used

Methodology Applied

Scientific EffectThermal treatment: Heat Treatment

Data Source

PatentUS20250132620A1Method for producing a component of an electric machine, component of an electric machine, and electric motor in an aircraft propulsion system including a component of this type

Publication Date: 2025.04.24 ROLLS ROYCE DEUT LTD & CO KG

AI summary

The invention relates to a method for producing a component (10) of an electric machine, wherein at least one permanent magnet means (1) of the component (10) is arranged on or at the component (10), together with at least one mechanical restraining means (2) for spatially fixing the at least one permanent magnet means (1), and the at least one mechanical restraining means (2) consists of a composite material or contains same, characterised in that, at least during a thermal treatment of the component (10), a means (3, F) is used for the targeted control of the magnetic field of the permanent magnet means (1).