Wound Core Lamination With Dense Bent Portions for Low Noise
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Solution Overview
Problem
Existing wound cores generate noise due to magnetostriction, and there is a need for further reduction in iron loss and noise.
Innovation Solution
The solution involves creating a laminated body with electrical steel sheets stacked in a ring shape, where bent portions have a higher stacking factor than the average, and using a compression means to reduce gaps between the sheets, particularly at these bent portions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If electrical steel sheets are stacked to form a wound core, then iron loss is reduced, but noise is generated due to magnetostriction
Solution Approach 1:
The patent applies different stacking factors to different regions of the wound core. Specifically, bent portions (corners) are given a higher stacking factor than straight portions, creating local quality differences that reduce noise at the most problematic locations while maintaining overall energy efficiency
Solution Approach 2:
The patent changes the stacking factor parameter from being uniform throughout the core to being variable, with bent portions having a stacking factor higher than the average of straight portions. This parameter change optimizes both noise reduction and iron loss characteristics
2Object-generated harmful factors
If gaps between electrical steel sheets are reduced, then noise is reduced, but manufacturing complexity increases
Solution Approach 1:
Instead of uniformly reducing gaps throughout the entire core (which would complicate manufacturing), the patent applies gap reduction selectively at bent portions where noise is most generated. This local approach maintains manufacturing simplicity while achieving noise reduction at critical locations
Solution Approach 2:
The patent applies partial action by focusing gap reduction only at bent portions rather than throughout the entire core. This selective approach achieves sufficient noise reduction without the excessive manufacturing complexity that would result from uniform gap reduction
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
This approach results in a wound core with reduced noise and iron loss by minimizing gaps at bent portions, thereby suppressing noise and maintaining a stable magnetic field.
Implementation Method 1
When an alternative magnetic field is applied to a wound transformer core, electrical steel sheets vibrate in the stacking direction due to magnetostriction generated in the electrical steel sheets. An acoustic wave is generated by the vibration from the gaps between the electrical steel sheets.
Data Source
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AI summary
A wound core equipped with a laminated body including plural electrical steel sheets stacked in a ring shape in side view. The laminated body includes plural bent portions, and plural block-shaped portions at positions between adjacent bent portions. At least one bent portion among the plural bent portions is a high stacking factor bent portion, wherein a stacking factor of the electrical steel sheets at the high stacking bent portion is higher than an average stacking factor of the steel sheets at the plural block-shaped portions.