Superconducting Magnetizer for Rare-Earth Permanent Magnets

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional magnetization methods, particularly in-situ magnetization using resistive magnetizers, face challenges in efficiently magnetizing rare-earth, high-coercivity permanent magnets due to high energy and fabrication costs, and inadequate magnetic field penetration, especially for larger magnets.

Innovation Solution

The use of superconducting materials in specially configured coils and cryostats allows for efficient in-situ magnetization of rare-earth permanent magnets within cylindrical rotors, with features like racetrack coils, non-conductive end spacers, and varied magnetic field configurations to enhance magnetic field saturation and penetration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional resistive magnetizers are used for in-situ magnetization, then the magnetization process can be performed, but the energy costs and fabrication costs become prohibitive

Engineering Contradiction:
Improvemagnetization process feasibilityVSAvoidenergy cost
Core Design Contradiction:
Ease of manufactureVSUse of energy by moving object

Solution Approach 1:

The patent replaces the conventional resistive (electrical heating-based) magnetizer system with a superconducting magnetizer system that uses superconducting coils to generate the magnetic field. This substitution eliminates the need for high-power resistive heating elements and associated cooling systems, dramatically reducing energy consumption while maintaining the capability to generate sufficient magnetic field flux for magnetizing rare-earth permanent magnets

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the operating parameters of the magnetizer by using superconducting materials that operate at cryogenic temperatures. This parameter change (from ambient temperature resistive heating to cryogenic superconducting operation) enables the system to achieve higher magnetic field intensities with lower energy input, as superconducting coils can carry much higher current densities without resistance losses

Inventive Principle:
Principle #35Parameter changes

2Quantity of substance

If conventional resistive magnetizers are used, then small magnets with low intrinsic coercivity can be magnetized, but large high-coercivity rare-earth magnets cannot be adequately magnetized due to inadequate field penetration

Engineering Contradiction:
Improvemagnet sizeVSAvoidmagnetic field penetration
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The superconducting magnetizer system replaces the conventional resistive system, enabling adequate field penetration for large high-coercivity rare-earth magnets. Superconducting coils can generate much stronger magnetic fields with higher current densities, providing sufficient field intensity to penetrate deep into large magnet volumes and overcome the high intrinsic coercivity of rare-earth materials

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs superconducting materials (such as NbTi or Nb3Sn alloys) that combine high critical current density, high critical magnetic field, and mechanical strength properties. These composite superconducting materials enable the magnetizer to generate the intense magnetic fields required for penetrating large high-coercivity magnets while maintaining structural integrity under high electromagnetic forces

Inventive Principle:
Principle #40Composite materials

3Reliability

If shaped materials are magnetized before insertion into the rotor, then the permanent magnets are fully magnetized, but electromagnetic interaction with surrounding objects complicates handling and insertion

Engineering Contradiction:
Improvemagnetization completenessVSAvoidhandling complexity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent applies preliminary action by performing the magnetization process after the shaped materials are already inserted into the rotor in their demagnetized state. The superconducting magnetizer then applies a strong magnetic field in-situ to magnetize the materials in their final positions, eliminating the need to handle and insert already-magnetized components that would experience electromagnetic interactions

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The superconducting magnetizer acts as an intermediary that enables magnetization after insertion. By providing the magnetic field source externally through the superconducting coils, the system allows materials to be inserted in a neutral, demagnetized state and then magnetized in-situ, serving as a mediator between the inserted materials and the desired magnetized state

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 reduces energy costs, allows for efficient magnetization of larger magnets, and increases throughput, enabling more robust and cost-effective magnetically-driven equipment with improved magnetic field control and reduced operational complexity.

Implementation Method 1

a superconducting magnetizer assembly including a plurality of superconducting coils configured to magnetize permanent magnet blocks within the rotor

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The present embodiments are generally directed towards improved systems and methods for the magnetization of materials disposed within a bulk material, such as the magnetization of as-formed permanent magnets disposed within an electric motor rotor. In accordance with the disclosed embodiments, one or more superconducting materials may be utilized to perform the in-situ magnetization

Methodology Applied
Scientific EffectSuperconductivity: Superconductivity

Data Source

PatentEP2477198B1System and method for magnetization of rare-earth permanent magnets
Publication Date: 2019.09.18 GENERAL ELECTRIC CO
  • EP2477198B1 patent drawingFigure 1~2
  • EP2477198B1 patent drawingFigure 3~5
  • EP2477198B1 patent drawingFigure 6~8

AI summary

The present disclosure is generally directed towards magnetization of permanent magnets (14) using superconducting magnetizers. For example, in one embodiment, a superconducting magnetizer assembly (18) is provided. The assembly includes a coil pack having an inner coil (44) including a first superconducting magnet material, the coil being configured to generate a first magnetic field in response to an electric current supplied to the coil, and an outer coil (42) including a second superconducting magnet material, the outer coil (42) being disposed about the inner coil (44) and being configured to generate a second magnetic field in response to an electric current supplied to the outer coil (42). The coil pack also includes a container configured to house the inner and the outer coils (42, 44).