Transformer Core Step-Lap Assembly Without Scrap or Overlap

Solution Overview

Problem

Conventional methods for assembling transformer cores result in design scrap and high iron losses, while also compromising mechanical strength due to overlapping joints and wastage during the cutting process.

Innovation Solution

The transformer core design incorporates multiple trapezoidal upper and lower yoke segments and an intermediate limb component with two segments, eliminating the need for notches and overlapping joints, and utilizing a step-lap joint structure with a predetermined offset to minimize material wastage and enhance mechanical strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If conventional lamination layer assembly with overlapping joints is used, then the transformer core can be assembled, but design scrap is generated and mechanical strength is compromised

Engineering Contradiction:

Improvedesign scrapVSAvoidmechanical strength

Core Design Contradiction:

Loss of substanceVSStrength

Solution Approach 1:

The lamination layer is divided into multiple discrete components (side limb components, yoke components, intermediate limb components) that are assembled together. This segmentation allows for precise fitting without overlapping joints, eliminating design scrap while maintaining structural integrity through the standardized component interfaces

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Multiple lamination layers are stacked and assembled to form the complete transformer core structure. The components are merged through precise fitting at joints without overlapping, eliminating material wastage while achieving the required mechanical strength through the cumulative effect of multiple bonded layers

Inventive Principle:

Principle #5Merging (Combining)

2Ease of manufacture

If conventional cutting process is used, then components can be formed, but design scrap is generated

Engineering Contradiction:

Improveease of assemblyVSAvoiddesign scrap

Core Design Contradiction:

Ease of manufactureVSLoss of substance

Solution Approach 1:

The lamination layer is divided into multiple discrete components (side limb components, yoke components, intermediate limb components) that are assembled together. This segmentation allows for precise fitting without overlapping joints, eliminating design scrap while maintaining structural integrity through the standardized component interfaces

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The standardized component design with consistent joint interfaces allows the same cutting and assembly processes to be applied universally across different transformer core sizes and configurations, improving ease of manufacture while eliminating the need for custom overlapping joints that generate scrap

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Device complexity

If overlapping joints are used, then assembly is simplified, but mechanical strength is compromised

Engineering Contradiction:

Improveassembly complexityVSAvoidmechanical strength

Core Design Contradiction:

Device complexityVSStrength

Solution Approach 1:

The lamination layer is divided into multiple discrete components (side limb components, yoke components, intermediate limb components) that are assembled together. This segmentation allows for precise fitting without overlapping joints, eliminating design scrap while maintaining structural integrity through the standardized component interfaces

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The joint interfaces between components are designed with precise geometric shapes (trapezoidal configurations with specific angles) that enable interlocking assembly. This geometric precision simplifies the assembly process by providing self-aligning joints while simultaneously enhancing mechanical strength through the interlocking nature of the connections

Inventive Principle:

Principle #14Spheroidality (Curvature)

Data Source

PatentUS20230402212A1Transformer core

Publication Date: 2023.12.14 HITACHI ENERGY LTD

AI summary

At least one lamination layer of a transformer core includes a first side limb component, a second side limb component, an upper yoke component including one or more upper yoke segments, a lower yoke component including one or more lower yoke segments, and an intermediate limb component including a first intermediate limb segment and a second intermediate limb segment. The upper yoke component is disposed in between an upper end of the first and second side limb component, the lower yoke component is disposed in between a lower end of the first and second side limb component, and a first end and a second end of the intermediate limb component is disposed in between two consecutive upper yoke segments and two consecutive lower yoke segments, respectively, where at least one of the upper yoke segment and the lower yoke segment is trapezoidal in structure.