Segmented Nd-Fe-B Magnets Insulating Adhesive Bonding
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Solution Overview
Problem
Traditional methods for segmenting Nd-Fe-B magnets using glass beads and adhesives face issues such as reduced adhesive strength, difficulty in maintaining insulation, and excessive glue control, leading to inconsistent product quality and magnet demagnetization due to eddy currents during high-speed operations.
Innovation Solution
A method involving pickling and phosphating of Nd-Fe-B magnet surfaces, followed by dot-coating and curing an insulating adhesive under controlled pressure and temperature, allowing for precise adhesive thickness and improved insulation, with optional degreasing and plasma activation, and subsequent cutting into segments using slicing or wire cutting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If glass beads are mixed with adhesives for segmentation, then insulation between magnets is achieved, but adhesive strength is reduced
Solution Approach 1:
The patent removes glass beads from the adhesive mixture entirely. Instead of mixing insulation material with the adhesive, the invention applies pure adhesive to bond magnet segments, achieving both strong adhesion and effective insulation without the compromising effects of glass bead inclusion.
2Reliability
If glass beads are used in adhesive application, then insulation is provided, but glass beads may move or be crushed making it difficult to maintain insulation characteristics
Solution Approach 1:
The invention extracts glass beads from the adhesive system, using only pure adhesive material. This eliminates the problems of bead movement and crushing, ensuring uniform insulation characteristics are maintained throughout the bonding process and final product.
3Ease of manufacture
If traditional sandwiching method is used, then magnets are bonded together, but excessive glue cannot be removed affecting product quality
Solution Approach 1:
The patent applies adhesive in controlled amounts before stacking the magnet segments, allowing precise control of glue distribution. This preliminary controlled application prevents excessive adhesive from occurring in the first place, eliminating the need for post-bonding glue removal and ensuring consistent product quality.
4Speed
If Nd-Fe-B magnets operate at high speed, then performance is improved, but eddy current is produced causing magnet demagnetization
Solution Approach 1:
The patent divides large magnet blocks into smaller segmented units that are bonded together with insulating adhesive between segments. This segmentation interrupts the eddy current paths that form in solid magnets during high-speed rotation, reducing eddy current losses and preventing demagnetization while maintaining high-speed operational performance.
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 enhances adhesive strength and controllability, reduces eddy current losses, and improves temperature management, resulting in more efficient and uniform segmentation of Nd-Fe-B magnets with better insulation and reduced demagnetization.
Implementation Method 1
eddy current will be produced during the high-speed operation in the magnet and then heat up the Nd-Fe-B magnets
Implementation Method 2
curing the insulating adhesive under pressure of 0.1 MPa to 20 MPa and a temperature from 20°C to 200°C
Data Source
Figure 1~2
Figure 3
AI summary
According to the present invention there is provided a method of segmentation Nd-Fe-B magnets. The method includes the steps as follows: a) Pickling and phosphating or sandblasting the surface of Ne-Fe-B magnets to remove rust and oil stains; b) Degreasing and activating the treated surfaces of the Nd-Fe-B magnets; c) Dispensing an insulating adhesive on the surfaces of Nd-Fe-B magnets; d) Putting the Nd-Fe-B magnets into an oven and curing at a temperature from 20°C to 200°C for 0.1h to 24h; e) Degreasing and activating the treated surfaces of the Nd-Fe-B magnets; f) Apply an insulating adhesive on the surfaces of Nd-Fe-B magnets; g) Stacking the Nd-Fe-B magnets together with a fixture tool and curing the insulating adhesive under pressure of 0.1Mpa to 20Mpa and a temperature from 20°C to 200°C; h) Cutting the bonded Nd-Fe-B magnets to a target size; and i) Coating the surfaces of the segmented Nd-Fe-B magnets.