Isotropic Powder Motor Core with Rounded Corners
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Solution Overview
Problem
Conventional electric steel plates used in motor cores have a low degree of freedom of shape, leading to increased size, weight, and cost due to sharp corners and the use of expensive copper wire, which also results in coating peeling issues.
Innovation Solution
A core formed from isotropic metallic powder with a high degree of freedom of shape, using a Cu-Al wire instead of pure copper wire, and a molding process involving press molding and thermal treatment to create a stator core with rounded corners and a reduced height winding part, connected obliquely to the inner part, allowing for reduced wire usage and weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If electric steel plate is used to form the core, then magnetic properties (flux density, permeability, strength) are improved, but the degree of freedom of shape is reduced and the core size increases
Solution Approach 1:
The invention changes the material form from laminated electric steel plates to isotropic soft magnetic powder, fundamentally altering the material's structural parameters to enable three-dimensional molding while maintaining magnetic properties. This allows the core to be formed into complex shapes with high degree of freedom, including rounded corners and optimized winding part geometries that are impossible with traditional steel plates
Solution Approach 2:
The invention uses composite soft magnetic powder materials with specific particle size distributions (5-50 μm) and isotropic characteristics, combining magnetic properties with moldability. The powder material can be compacted into dense cores that exhibit both excellent magnetic performance and shape flexibility, resolving the contradiction between magnetic strength and shape freedom
2Ease of manufacture
If electric steel plate with sharp corners is used, then manufacturing is simplified, but wire coating peeling occurs and reliability decreases
Solution Approach 1:
The invention applies curvature by forming the core from isotropic powder into shapes with rounded corners and smooth surfaces. The three-dimensional molding process naturally produces curved transitions instead of sharp corners, eliminating stress concentration points that cause wire coating peeling while maintaining manufacturing efficiency through automated powder compacting
3Reliability
If wound copper wire is used on the core outer surface, then electrical connectivity is achieved, but weight and cost increase significantly
Solution Approach 1:
The invention changes the wire material parameter from pure copper to copper-aluminum alloy, reducing density while maintaining electrical conductivity. The alloy composition (Cu-30%Al or similar) provides sufficient conductivity for motor applications at approximately half the weight of pure copper wire, directly addressing the weight reduction goal
4Ease of manufacture
If the core axial length is increased to accommodate wire winding, then wire winding space is sufficient, but the overall motor size increases
Solution Approach 1:
The invention transitions from two-dimensional planar winding surfaces to three-dimensional curved surfaces on the core. The rounded corners and optimized geometry of the powder-formed core create additional winding space in radial and circumferential directions, allowing sufficient wire accommodation without increasing axial length. This dimensional approach to space utilization reduces the motor's overall size
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
The solution results in a smaller, lighter, and more cost-effective motor core with improved magnetic properties and reduced wire usage, achieving up to 50% weight reduction in wire and enhanced motor performance.
Implementation Method 1
a molding process involving press molding and thermal treatment to create a stator core
Implementation Method 2
a molding process involving press molding and thermal treatment to create a stator core
Data Source
AI summary
A core formed from powder, such as a stator core for use in a motor for a vehicle, wherein the core is formed from metallic powder and includes an outer part disposed at an inside of the motor, an inner part disposed at an inside of the motor, and a winding part which connects the outer part and the inner part and on which a wire is wound, and to a motor for a vehicle using the same. The winding part is formed to have rounded corners and a height lower than the height of the inner part, and a connection part is obliquely formed between the winding part and the inner part so that the winding part and the inner part are naturally connected.