Laminated Stator Core Thin Section Elongation
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Solution Overview
Problem
Conventional methods for producing laminated stator cores from magnetic metal sheets result in low material yield, damaged die devices, and reduced magnetic characteristics due to inadequate thin section formation, which affects torque and motor performance.
Innovation Solution
The laminated stator core is formed by punching stator core sheets with thin sections that have a thickness of 50-95% and radial length of 30-100% of the magnetic metal sheet, with grooves on the magnetic pole shaft pieces to improve elongation and interlocking accuracy, reducing magnetic flux irregularities and preventing punch damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the coining depth is set deep to secure sufficient elongation of the magnetic pole shaft piece, then the elongation is improved, but the magnetic characteristics are deteriorated and torque characteristics are reduced
Solution Approach 1:
The invention changes the parameter of thin section thickness from less than 50% (conventional) to 50-95% of the magnetic metal sheet thickness. This parameter change provides sufficient elongation for interlocking while maintaining magnetic characteristics, as the thicker section preserves magnetic flux paths while still enabling adequate radial elongation for caulking engagement.
2Length of moving object
If the groove is made deeper to increase the elongation, then the elongation is improved, but the magnetic pole tooth piece is bent upwardly and magnetic characteristics are reduced
Solution Approach 1:
By changing the thickness parameter to 50-95% of the original sheet thickness, the invention achieves sufficient elongation without requiring excessive groove depth. This prevents upward bending of the magnetic pole tooth piece while maintaining the desired radial elongation for interlocking, thus preserving the structural form of the laminated stator core.
3Length of moving object
If the magnetic metal sheet is deeply pressed by the punch to form the thin section, then the elongation is improved, but the punch may be damaged due to insufficient strength
Solution Approach 1:
The invention reduces the required pressing depth by setting the thin section thickness to 50-95% of the original sheet thickness. This parameter change means the punch does not need to penetrate as deeply, reducing the risk of punch damage while still achieving sufficient elongation for interlocking through the optimized balance between thickness and radial length.
4Loss of substance
If the rotor core sheet and stator core sheet are punched out concentrically from one magnetic metal sheet, then the material yield is improved, but the magnetic pole teeth cannot be punched out in desired shapes
Solution Approach 1:
The invention segments the punching process into two sequential operations: first punching the rotor core sheet, then punching the stator core sheet with magnetic pole teeth. This segmentation allows each component to be punched with optimized tooling for its specific shape requirements, maintaining manufacturing precision while achieving high material yield through concentric punching from one sheet.
5Manufacturing precision
If different punches and dies are used for rotor core sheet and stator core sheet, then the shape of magnetic pole teeth is improved, but the material yield is reduced and cost is increased
Solution Approach 1:
The invention segments the punching operations into sequential steps with different punches and dies, allowing each component to be optimized for its specific geometry. The rotor core sheet is punched first with one set of tooling, then the stator core sheet with magnetic pole teeth is punched with optimized tooling for tooth shapes. This segmentation maintains high manufacturing precision for magnetic pole teeth while improving material yield compared to non-concentric arrangements.
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 enhances magnetic characteristics, reduces torque losses, and simplifies die resetting, leading to improved motor performance and productivity while maintaining die integrity.
Implementation Method 1
the thin section is formed by pressing a part or a whole of the magnetic pole shaft piece in a thickness direction thereof, and elongating the magnetic pole shaft piece in a radially inward direction
Data Source
AI summary
A laminated stator core 10, formed by laminating stator core sheets 17, each of the stator core sheets 17 punched out from a magnetic metal sheet 32 so as to have a common axis with a rotor core sheet 36 which punched out from the magnetic metal sheet 32 before the stator core sheet 17 is punched out; the stator core sheet 17 including a thin section 24 in a magnetic pole shaft piece 20; the thin section 24 formed by pressing a part or a whole of a magnetic pole shaft piece 20 in a thickness direction, and elongating the same in a radially inward direction; and further the thin section 24 having a thickness within 50-95% of that of the magnetic metal sheet 32 and a radial length within 30-100% of that of the magnetic pole shaft piece 20. This enables a magnetic pole piece 19 to be elongated to form the thin section 24 without adverse effect on magnetic characteristics thereof, and improves caulking accuracy and dimensional accuracy for blanking both of the core sheets 17, 36 from one magnetic metal sheet 32.