Laminated Core Adhesive SP Matching for Oil-Contaminated Steel Sheets
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Solution Overview
Problem
Existing laminated cores face challenges in achieving sufficient adhesion strength between punched electrical steel sheets due to the interference of punching oil, which disrupts the adhesion process.
Innovation Solution
The use of an adhesive with an SP value between 7.8 to 10.7 (cal/cm³)¹/², preferably composed of an epoxy resin or acrylic resin, to enhance compatibility with punching oil and ensure high adhesion strength between electrical steel sheets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional adhesives (epoxy resin or acrylic resin) are used to bond punched electrical steel sheets, then adhesion is attempted, but sufficient adhesion strength cannot be obtained due to interference from punching oil
Solution Approach 1:
The patent changes the chemical parameter of the adhesive by specifying an SP value range (7.8 to 10.7 cal^1/2/cm^3/2), which determines the adhesive's solubility characteristics. This parameter change enables the adhesive to be compatible with punching oil, allowing effective adhesion despite the presence of oil on the steel sheet surfaces.
Solution Approach 2:
The patent converts the harmful effect of punching oil into a beneficial condition by selecting an adhesive whose SP value matches the oil's solubility characteristics. This compatibility allows the adhesive to function effectively in the presence of oil, transforming the previously harmful oily environment into an acceptable bonding condition.
2Shape
If electrical steel sheets are punched to create motor components, then necessary shapes are achieved, but punching oil remains on surfaces preventing proper adhesion
Solution Approach 1:
The patent changes the adhesive's chemical parameter (SP value) to match the punching oil's solubility characteristics. This parameter adjustment allows the adhesive to bond effectively to steel sheets that still have punching oil residues, eliminating the need for additional cleaning steps while maintaining strong adhesion.
3Strength
If adhesion strength is increased to overcome punching oil interference, then bonding may improve, but adhesion uniformity across different SP value conditions becomes difficult to maintain
Solution Approach 1:
The patent establishes a specific SP value range (7.8 to 10.7 cal^1/2/cm^3/2) for the adhesive, which provides optimal compatibility with typical punching oils. This controlled parameter range ensures consistent adhesion performance across varying oil conditions, maintaining both strength and uniformity.
Solution Approach 2:
The adhesive is formulated as a composite material containing both epoxy resin and acrylic resin components. This composite structure combines the strength characteristics of epoxy with the flexibility and adhesion properties of acrylic, creating a formulation that maintains uniform performance across different punching oil conditions.
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 adhesive achieves a laminated core with improved mechanical strength, reduced noise, and vibration, while maintaining excellent magnetic properties and adhesion even in the presence of varying SP values between the adhesive and punching oil.
Implementation Method 1
punched electrical steel sheets are adhered to each other with a high adhesion strength
Data Source
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AI summary
Provided is an electric motor using a laminated core in which punched electrical steel sheets are adhered to each other with a high adhesion strength. The laminated core includes: a plurality of electrical steel sheets which are stacked on each other and of which both surfaces are coated with an insulation coating; and an adhesion part which is disposed between the electrical steel sheets adjacent to each other in a stacking direction and adheres the electrical steel sheets to each other, wherein all sets of the electrical steel sheets adjacent to each other in the stacking direction are adhered to each other by the adhesion parts, wherein the adhesion parts are provided at a plurality of positions between the electrical steel sheets, and wherein the adhesion part is a layer made of an adhesive containing any one or both of an acrylic resin and an epoxy resin and having an SP value of 7.8 to 10.7 (cal/cm3)1/2.