Adhesive Insulation Coating for Electrical Steel Lamination Accuracy
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Solution Overview
Problem
Existing electrical steel sheets with insulation coatings face challenges in maintaining magnetic properties and lamination performance due to mechanical and thermal stress, leading to deteriorated core performance in rotating electric machines.
Innovation Solution
An electrical steel sheet with an insulation coating having an adhesive ability, where the logarithmic decrement in specific temperature ranges is controlled to ensure improved workability, lamination accuracy, and adhesive strength, minimizing uneven curing and noise, and achieving both lamination factor and adhesive strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If caulking or welding is used to bond electrical steel sheets, then bonding strength is improved, but magnetic properties deteriorate due to mechanical stress and thermal stress
Solution Approach 1:
The patent replaces mechanical bonding methods (caulking, welding) with a chemical bonding method using an insulation coating having adhesive ability. The coating forms chemical bonds with adjacent steel sheets through adhesion, eliminating the need for mechanical stress or thermal stress that would otherwise damage magnetic properties.
Solution Approach 2:
The insulation coating acts as an intermediary substance between adjacent electrical steel sheets. This coating layer with adhesive ability bonds the sheets together while isolating them electrically and magnetically, preventing direct contact that would require mechanical or thermal bonding processes.
2Strength
If insulation coating with adhesive ability is used, then bonding strength is improved, but uneven curing occurs leading to noise
Solution Approach 1:
The patent controls the logarithmic decrement parameter of the insulation coating within a specific range (0.05 to 0.40) to optimize curing behavior. By adjusting this parameter, the coating achieves uniform curing across the bonding surface, preventing the uneven curing that causes noise while maintaining adequate adhesive strength.
3Object-generated harmful factors
If logarithmic decrement of insulation coating is reduced, then uneven curing is minimized and noise is reduced, but adhesive strength may be compromised
Solution Approach 1:
The patent identifies and controls multiple parameters of the insulation coating simultaneously: logarithmic decrement (0.05 to 0.40), glass transition temperature (50°C to 150°C), and curing start temperature (80°C to 200°C). By coordinating these parameters within specific ranges, the coating achieves both low noise (through uniform curing) and high adhesive strength.
Solution Approach 2:
The insulation coating is designed as a composite material with specific viscoelastic properties characterized by controlled logarithmic decrement and glass transition temperature. This composite structure provides both the uniform curing needed for noise reduction and the adhesive properties needed for strong bonding.
4Ease of manufacture
If mechanical stress is applied during punching, then workability is improved, but magnetic properties deteriorate
Solution Approach 1:
The insulation coating is applied to the electrical steel sheets before punching operations. This preliminary coating layer protects the steel sheet surface and reduces friction during punching, improving workability while preventing direct mechanical stress transmission that would damage magnetic properties.
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 controlled insulation coating on the electrical steel sheets enhances the core performance by improving workability during punching, lamination accuracy, reducing noise, and achieving high adhesive strength between sheets, resulting in improved laminated core performance.
Implementation Method 1
a method of laminating electrical steel sheets having an insulation coating having an adhesive ability on the surface and adhering them to each other
Implementation Method 2
a difference between a peak temperature of the logarithmic decrement of the insulation coating and a curing start temperature is less than 80° C.
Data Source
AI summary
This electrical steel sheet is an electrical steel sheet in which at least part of either or both surfaces of a base steel sheet is coated with an insulation coating having an adhesive ability, wherein a logarithmic decrement of the insulation coating in a temperature range of 25 to 100° C. is 0.3 or less.