Laminated Core Joining Layout for Magnetic Properties and Shape Accuracy

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

There is a need to improve the magnetic properties of laminated cores while ensuring dimensional accuracy of the outer shape in existing technologies.

Innovation Solution

A laminated core design where electrical steel sheets on the sides are interlocked but not adhered, and those in the center are adhered but not interlocked, with specific adhesive and interlocking configurations to enhance dimensional accuracy and reduce strain, thereby improving magnetic properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If all electrical steel sheets are interlocked, then dimensional accuracy is improved, but magnetic properties deteriorate due to increased strain

Engineering Contradiction:

Improvedimensional accuracyVSAvoidmagnetic properties

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent applies different joining methods to different regions of the laminated core: interlocking is used for outer electrical steel sheets to ensure dimensional accuracy, while adhesion is used for inner electrical steel sheets to minimize strain and protect magnetic properties. This localized differentiation resolves the contradiction by optimizing each region for its specific functional requirement.

Inventive Principle:

Principle #3Local quality

2Reliability

If all electrical steel sheets are adhered, then magnetic properties are improved by reducing strain, but dimensional accuracy deteriorates

Engineering Contradiction:

Improvemagnetic propertiesVSAvoiddimensional accuracy

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies different joining methods to different regions of the laminated core: adhesion is used for inner electrical steel sheets to minimize strain and protect magnetic properties, while interlocking is used for outer electrical steel sheets to ensure dimensional accuracy. This localized differentiation resolves the contradiction by optimizing each region for its specific functional requirement.

Inventive Principle:

Principle #3Local quality

3Manufacturing precision

If outer electrical steel sheets are interlocked, then outer shape accuracy is improved, but handleability deteriorates

Engineering Contradiction:

Improveouter shape accuracyVSAvoidhandleability

Core Design Contradiction:

Manufacturing precisionVSEase of operation

Solution Approach 1:

The patent applies interlocking only to outer electrical steel sheets that form the outer shape, while inner sheets are adhered to maintain flexibility and handleability. This selective application resolves the contradiction by ensuring outer shape accuracy where needed while preserving overall handleability through the flexible inner core.

Inventive Principle:

Principle #3Local quality

Data Source

PatentEP3902110B1Laminated core and electric motor

Publication Date: 2026.01.28 NIPPON STEEL CORPORATION

Figure 1
Figure 2
Figure 3

AI summary

A laminated core includes a plurality of electrical steel sheets stacked on each other, wherein, among the plurality of electrical steel sheets, both of the electrical steel sheets located on a first side in a stacking direction and the electrical steel sheets located on a second side in the stacking direction are fastened to each other but are not adhered to each other, and the electrical steel sheets located in a center in the stacking direction are adhered to each other but are not fastened to each other.