Step-Lap Iron Core Joints With Local Magnetic Domain Refinement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In iron cores for stationary induction apparatuses, the step-lap joint parts between yoke and leg parts cause increased magnetic resistance and iron loss due to the flow of magnetic flux across air gaps and staggered abutments of electromagnetic steel plates.
Innovation Solution
The iron core is configured with electromagnetic steel plates laminated in a staggered manner, and magnetic domain fine differentiation is achieved by subjecting the end surfaces of the plates to warping-derived magnetic domain fine differentiation, specifically through grid-pattern laser irradiation, to reduce magnetic resistance at the joint parts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If electromagnetic steel plates are laminated in a stepwise staggered manner to form joint parts, then the structural integrity and assembly are improved, but magnetic resistance increases and iron loss occurs at the joint parts
Solution Approach 1:
The patent applies magnetic domain fine differentiation processing (laser irradiation in grid pattern) specifically at the joint parts where end portions of electromagnetic steel plates abut one another. This localized treatment modifies the magnetic properties only at the problematic joint regions, reducing magnetic resistance and iron loss without affecting the overall staggered lamination structure that provides structural integrity.
Solution Approach 2:
The patent changes the magnetic domain structure parameter at the joint parts through laser irradiation processing. By subjecting the surface of electromagnetic steel plates at joint parts to magnetic domain fine differentiation, the magnetic flux distribution is optimized, reducing rotational magnetic flux and thereby reducing iron loss while maintaining the staggered lamination configuration.
2Ease of manufacture
If a nonmagnetic sheet member is located at the joint part to provide an air gap, then assembly alignment is improved, but magnetic resistance increases and loss occurs
Solution Approach 1:
The patent removes the nonmagnetic sheet member (air gap) from the joint part configuration. Instead of providing an air gap for assembly alignment, the invention uses precise staggered lamination of electromagnetic steel plates with magnetic domain fine differentiation processing at the joint parts, eliminating the source of magnetic resistance loss while maintaining assembly feasibility through the staggered configuration itself.
3Loss of energy
If laser irradiation is applied in a grid pattern to the entire surface of electromagnetic steel plates, then magnetic domain fine differentiation is achieved, but processing time and cost increase
Solution Approach 1:
The patent applies laser irradiation processing only at specific joint parts where end portions of electromagnetic steel plates abut one another, rather than treating the entire surface. This localized approach reduces processing time and cost while still achieving the necessary magnetic domain fine differentiation to reduce iron loss at the critical joint regions where rotational magnetic flux occurs.
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 configuration significantly reduces iron loss by minimizing magnetic resistance at the joint parts, particularly at higher magnetic flux densities, while maintaining an adequate processing area without unnecessary processing.
Implementation Method 1
the electromagnetic steel plates are provided with a magnetic domain fine differentiation processed part, which is located on the portion, of a surface of the end portion of each of the electromagnetic steel plates, lapped with the joint part of another electromagnetic steel plate, and which has been subjected to warping-derived magnetic domain fine differentiation
Implementation Method 2
Patent Literature 1 therefore makes a proposition to perform magnetic domain fine differentiation control by subjecting the surface of the electromagnetic steel plate constituting the laminated iron core to magnetic domain fine differentiation which involves laser irradiation in a grid pattern
Data Source
AI summary
An iron core (1, 11, 31) for a stationary induction apparatus according to one embodiment is configured by laminating a plurality of electromagnetic steel plates (5, 16, 33). The electromagnetic steel plates are laminated so that joint parts (6, 17, 18, 32), at which the end portions of the electromagnetic steel plates abut one another, are disposed in a staggered manner; and the electromagnetic steel plates are provided with a magnetic domain fine differentiation processed part (7, 19, 34), which is located on the portion, of a surface of the end portion of each of the electromagnetic steel plates, lapped with the joint part of another electromagnetic steel plate, and which has been subjected to warping-derived magnetic domain fine differentiation.