Halbach Magnet Array Assembly with Controlled Residual Magnetization
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Solution Overview
Problem
Existing methods for manufacturing Halbach magnetic circuits face challenges in accurately controlling magnet positions due to repulsion between magnets, and they often result in a small ratio of magnetic-flux density between the front and back surfaces.
Innovation Solution
A method involving the magnetization of first and second magnetic material pieces in specific directions, with the first pieces magnetized parallel to a first direction and the second pieces perpendicular, under conditions where the residual magnetization ratio of the first pieces is greater than that of the second pieces, to create a Halbach magnet array with a large front-to-back magnetic-flux density ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a plurality of magnetized magnets are glued together to manufacture a Halbach magnetic circuit, then the magnetic-flux density can be achieved, but repulsion between the magnets makes it difficult to accurately control the positions of the magnets, requiring a large external force
Solution Approach 1:
The patent applies preliminary action by magnetizing the magnetic material pieces before assembly. The magnetic pieces are magnetized in predetermined directions while in an unmagnetized state during assembly, which eliminates repulsion forces that would otherwise make position control difficult. This preliminary magnetization step allows for accurate positioning without requiring large external forces to overcome magnetic repulsion between adjacent magnets.
2Manufacturing precision
If a plurality of unmagnetized magnetic materials are glued together and then magnetized in predetermined directions, then position control is improved, but the Halbach magnetic circuit tends to have a small ratio of magnetic-flux density of the front surface to that of the back surface
Solution Approach 1:
The patent applies local quality by creating different magnetization states in different regions of the magnetic assembly. Specifically, first magnetic material pieces are magnetized to a first residual magnetization ratio while second magnetic material pieces are magnetized to a second residual magnetization ratio, with the two ratios being different. This local differentiation of magnetic properties enables the front surface to have high magnetic flux density while the back surface has low magnetic flux density, achieving the desired Halbach configuration with a large flux density ratio.
3Reliability
If multiple magnetic material pieces with different residual magnetization ratios are used, then a large front-to-back magnetic-flux density ratio is achieved, but the manufacturing process complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the magnetic circuit into first magnetic material pieces and second magnetic material pieces that are alternately arranged. Each type of piece has a different residual magnetization ratio, allowing independent optimization of magnetic properties for different regions. This segmentation enables the achievement of a large front-to-back magnetic-flux density ratio through a systematic arrangement of magnetized and unmagnetized pieces, making the complex manufacturing process more manageable and suitable for mass production.
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 method allows for easy and efficient manufacturing of Halbach magnet arrays with a high front surface magnetic-flux density and low back surface magnetic-flux density, making it suitable for mass production.
Implementation Method 1
magnetizing at least two first magnetic material pieces in a direction parallel to a first direction
Implementation Method 2
r1 is a residual magnetization ratio of the at least two first magnetic material pieces
Implementation Method 3
causes one surface (a front surface) of the Halbach magnetic circuit to have a high surface magnetic flux (surface magnetic-flux density) and an opposite surface (a back surface) to have a low surface magnetic flux
Data Source
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AI summary
The method for manufacturing the Halbach magnet array includes the steps of: (a) magnetizing at least two first magnetic material pieces in a direction parallel to a first direction, and (b) magnetizing at least one second magnetic material piece in a direction parallel to a second direction perpendicular to the first direction, in this order. In the step (a), the first magnetic material pieces and the second magnetic material piece are alternately arranged in the second direction with the first magnetic material pieces being each adhered to the adjacent second magnetic material piece, and the magnetization is performed under a condition in which a residual magnetization ratio rl of the first magnetic material pieces is higher than a residual magnetization ratio r2 of the second magnetic material piece.