Magnetic Mandrel Stacking for Aligned Motor Sheet Sectors
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Solution Overview
Problem
The existing methods for manufacturing stacks of sheet metal sectors for rotating electrical machines are complex and inefficient, particularly due to the difficulty in aligning and securing sectors without causing separation, leading to increased manufacturing costs and material waste.
Innovation Solution
A device featuring a mandrel with magnetizable bars and alignment latches allows for the easy alignment and secure stacking of sheet metal sectors by utilizing magnetic attraction to maintain sector position during the stacking process, reducing the need for precise alignment tools and minimizing material waste.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If sheet metal sectors are stacked using traditional mechanical alignment methods, then alignment precision can be achieved, but the manufacturing complexity increases and sectors may separate during stacking
Solution Approach 1:
The patent replaces traditional mechanical alignment systems with a magnetic field-based alignment system. Magnets embedded in the mandrel create magnetic fields that automatically align sheet metal sectors during stacking, eliminating the need for complex mechanical alignment tools and procedures while maintaining high precision.
Solution Approach 2:
The patent introduces magnets as an intermediary element between the mandrel and sheet metal sectors. These magnets serve as a mediator that creates magnetic attraction forces to hold and align sectors in position during stacking, simplifying the overall manufacturing process while ensuring precise alignment.
2Manufacturing precision
If radial thrust is applied from inside to outside to expand mandrel for alignment, then bore alignment improves, but sectors separate
Solution Approach 1:
The patent inverts the traditional expansion mechanism by applying magnetic attraction forces from the outside inward rather than mechanical thrust from inside outward. The magnets on the mandrel create radial inward forces that pull sectors toward the center, achieving both alignment and preventing separation simultaneously.
Solution Approach 2:
The patent replaces mechanical radial thrust with magnetic attraction forces. Instead of using mechanical expansion that pushes sectors outward and causes separation, the magnetic field creates attractive forces that pull sectors inward toward the mandrel, maintaining sector integrity while achieving alignment.
3Ease of manufacture
If complete sheet cutting is used to simplify construction, then manufacturing simplicity increases, but material waste increases
Solution Approach 1:
The patent divides complete sheets into multiple sectors that can be selectively used. Instead of cutting entire sheets, the sheet metal is segmented into sector pieces that fit together like puzzle pieces, reducing material waste while maintaining manufacturing simplicity through the modular sector design.
Solution Approach 2:
The patent applies different qualities to different parts of the sheet metal by creating sectors with specific geometries and properties tailored to their intended positions in the final product. This allows optimization of material usage while maintaining construction simplicity through standardized sector interfaces.
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 solution simplifies the stacking process, ensures accurate geometry, and reduces material consumption by allowing for the use of less expensive sheet metal for the rotor and higher quality metal for the stator, facilitating automation and minimizing the risk of sector movement during the manufacturing of rotating electrical machines.
Implementation Method 1
the magnetization system makes it possible to magnetize the bars, which can thus attract, when magnetized, the sheet metal sectors which come closer to the mandrel body, undergoing a radial thrust from the outside towards the center
Data Source
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AI summary
Device (1) for manufacturing a stack of sheets (E) for a rotating electrical machine, each sheet comprising a plurality of sheet sectors (10) forming notches (11), the sheets providing a central bore, the device (1) comprising a mandrel (20) for receiving the stacked sheet sectors (10), the mandrel (20) comprising: - a mandrel body (25) provided with longitudinal grooves (26), - bars (30) received in the longitudinal grooves (26) of the mandrel body (25), the bars (30) being magnetizable, - a magnetization system (40) for the bars, and - alignment tabs (50), intended to be received in the notches (11) of the sheets so as to ensure the alignment of the notches (11).