Resin-Bonded Laminated Magnetic Material for High-Frequency Core Loss
Solution Overview
Problem
Existing techniques for laminated magnetic materials fail to effectively suppress iron loss, particularly eddy current loss, in high-frequency bands due to high-speed motor rotation and inverter drive harmonics, which deteriorates magnetic properties.
Innovation Solution
A laminated magnetic material comprising quenched alloy strips with a resin layer between them, where the adhesive stress is maintained at 1.8 MPa or more, achieved by calculating the adhesive stress using specific physical properties of the resin and the alloy strips.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If amorphous alloy strips with thickness of about 25 μm are used to reduce eddy current loss, then eddy current loss is reduced, but the number of laminations required increases 10 times or more compared to electrical steel sheets
Solution Approach 1:
The invention divides the thin amorphous alloy strip (25 μm) into multiple thinner layers by bonding several strips together with resin layers. This segmentation allows the total thickness to be increased to match electrical steel sheet dimensions while maintaining the low eddy current loss characteristics of thin amorphous alloy layers, thereby reducing the number of laminations needed in the final assembly.
Solution Approach 2:
The invention creates a composite structure by bonding multiple amorphous alloy strips with resin layers in between. This composite approach combines the advantages of thin amorphous alloy (low eddy current loss) with the practical handling benefits of thicker electrical steel sheets, achieving both energy efficiency and manufacturing feasibility.
2Ease of operation
If multiple thin amorphous alloy strips are bonded together to form thicker plates, then handling becomes easier, but adhesive stress is insufficient leading to deterioration of magnetic properties in high-frequency bands
Solution Approach 1:
The invention changes the physical and chemical parameters of the resin adhesive, specifically selecting resins with high modulus of elasticity (γ ≥ 2000 MPa) and appropriate coefficients of linear expansion (α1 ≥ 50×10⁻⁶/K). By optimizing these parameters, the adhesive stress is enhanced to 1.8 MPa or more, which maintains magnetic domain refinement and preserves magnetic properties in high-frequency bands while enabling easier handling of thicker laminated structures.
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
The solution results in a laminated magnetic material with significantly reduced iron loss characteristics, specifically achieving iron loss of 13.0 W/kg or less at 2000 Hz and eddy current loss of 9.5 W/kg or less, maintaining excellent magnetic properties in high-frequency bands.
Implementation Method 1
a coefficient of linear expansion of the resin at room temperature is denoted by α1 [1/K], a curing temperature of the resin is denoted by Ta [K], a coefficient of linear contraction of the resin during curing is denoted by β
Implementation Method 2
an adhesive stress σ [MPa] represented by the following equation is 1.8 MPa or more
Implementation Method 3
a coefficient of linear contraction of the resin during curing is denoted by β
Data Source
AI summary
The present invention provides: a laminated magnetic material for a motor, the material having low core loss characteristics even in a high-frequency band; and a method for manufacturing said laminated magnetic material for a motor. Provided is a laminated magnetic material provided with a plurality of quenched alloy strips and a resin layer made of resin and disposed between the quenched alloy strips. The laminated magnetic material is characterized in that the adhesive stress σ [MPa] represented by the following equation is 1.8 MPa or greater when the modulus of elasticity of the resin at room temperature is denoted by γ [MPa], the coefficient of linear expansion of the resin at room temperature is denoted by α1 [1/K], the curing temperature of the resin is denoted by Ta [K], the coefficient of linear contraction of the resin during curing is denoted by β, the thickness of the resin is denoted by h1 [μm], the thickness of the quenched alloy strips is denoted by h2 [μm], the coefficient of linear expansion of the quenched alloy strips is denoted by α2 [1/K], and room temperature is denoted by RT. σ=h1/h2×γ×{(α1−α2)×(Ta−RT)+β}.