Magnetic Sheet Laminate Sintering for Thin Motor Cores
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for producing magnetic laminations for electrical machines result in high waste generation, high production costs, and limited ability to achieve the required thickness for high-power-density motors, with significant investment in production facilities needed for large-scale production.
Innovation Solution
A method involving the application of an inorganic electrically insulating layer with a thin-film process followed by a metallic layer containing organic binders, which is then debindered and sintered to form a magnetic sheet, allowing for precise control of the magnetic sheet's contour and reducing the need for post-sintering separation layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If magnetic laminations are punched out of a continuous coil, then production capacity is maintained, but waste generation increases and manufacturing cost increases
Solution Approach 1:
The patent changes the fundamental parameter of magnetic sheet production from subtractive punching to additive printing. By depositing magnetic material directly in the desired pattern, the process eliminates material waste while maintaining production capacity. The printing process allows precise control of material placement, achieving near 100% material utilization efficiency.
Solution Approach 2:
The patent replaces the mechanical punching system with a printing-based system. Instead of using punches and dies to cut magnetic sheets from coils, the invention uses deposition processes to build up magnetic material layer by layer in the required pattern, substituting mechanical removal with controlled material addition.
2Power
If magnetic laminations are made thinner to increase power density, then power density improves, but mechanical strength decreases
Solution Approach 1:
The patent creates a composite structure by integrating the electrically insulating layer directly into the magnetic sheet during the printing process. This composite design allows thin magnetic laminations to maintain mechanical strength through the reinforcing effect of the insulating layer, which acts as both structural support and electrical isolation.
Solution Approach 2:
The patent applies different material properties to different regions of the magnetic sheet. The insulating layer is strategically positioned at critical locations where electrical isolation and mechanical reinforcement are needed, while the magnetic material is optimized for electromagnetic performance. This local differentiation allows thin sheets to achieve both high power density and adequate strength.
3Manufacturing precision
If screen printing is used to print magnetic sheets, then near-net-shape production is achieved, but investment in production facilities increases
Solution Approach 1:
The patent creates a multi-functional printing system that performs multiple operations in a single process step. The printing apparatus simultaneously deposits magnetic material, forms the electrically insulating layer, and creates the final magnetic sheet geometry. This consolidation of functions into one universal process reduces the need for separate specialized equipment for each operation.
Solution Approach 2:
The patent merges the application of magnetic material and electrically insulating layer into a single integrated printing process. Instead of separately applying insulating layers after magnetic sheet formation, the invention combines both material depositions in one coordinated printing operation, simplifying the production facility requirements.
4Reliability
If electrically insulating layer is applied after sintering, then electrical insulation is achieved, but process complexity increases and separation layers are required
Solution Approach 1:
The patent performs the application of the electrically insulating layer before the sintering process. By pre-applying the insulating layer to the green state magnetic material and then sintering the combined structure, the process eliminates the need for post-sintering insulating layer application and removes the requirement for separation layers between stacked magnetic sheets.
Solution Approach 2:
The patent combines the magnetic material and electrically insulating layer into a single integrated structure that is sintered together as one unit. This merging of materials and processes creates a monolithic component where the insulating layer and magnetic sheet are inseparably bonded, eliminating the need for separate application steps and separation layers.
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 method enables the production of magnetic sheets with higher power density and mechanical strength, suitable for industrial-scale manufacturing with reduced equipment investment, and improves process control by eliminating the need for post-sintering separation layers.
Implementation Method 1
Applying an inorganic, electrically insulating layer to a substrate with a layer thickness of less than 20 μm by means of a thin-film process
Implementation Method 2
feeding the debindered layered laminate to a sintering process and sintering the magnetic sheet
Data Source
Figure 1
Figure 2a~2e
Figure 3a~3d
AI summary
The invention relates to a method for producing a magnetic sheet (2) for an electrical machine, comprising the following steps: - applying an inorganic, electrically insulating layer to a substrate (6) with a layer thickness (8) of less than 20 µm by means of a thin-film process (15), - in such a way that a surface contour (10) of the electrically insulating layer (4) substantially corresponds to a final contour of the magnetic sheet (12), - applying a metallic layer (14) to the electrically insulating layer (4), - wherein the metallic layer (14) has a layer thickness (16) of less than 200 µm and - comprises organic binders, - so that a layer laminate (18-1) is formed, - detaching the layer laminate (18-1) from the substrate (6), - removing the binders from the metallic layer (14), - feeding the debindered layer laminate (18-2) to a sintering process (20) and sintering the Magnetic sheet (2).