Insulated Soft Magnetic Stator Structure for Eddy Current Reduction
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Solution Overview
Problem
Conventional laminated stator cores for electric machines, such as DC brushless motors, are labor-intensive to fabricate, constrain motor geometry, and limit magnetic circuit configurations, leading to sub-optimal performance and difficulty in incorporating cooling, which affects efficiency and torque output.
Innovation Solution
A system and method for creating a structured material with insulated boundaries using droplet spray deposition, where molten alloy droplets are coated with an insulation layer in-flight or on deposition, forming domains with insulated boundaries to enhance magnetic path efficiency and reduce eddy current losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional laminated stator cores are used, then magnetic path efficiency is maintained, but manufacturing complexity and labor intensity increase
Solution Approach 1:
The patent combines multiple fabrication steps (cutting, insulating coating, assembly) into a single integrated process by forming the stator core from a single piece of magnetic material using additive manufacturing, eliminating the need for separate lamination and assembly operations
Solution Approach 2:
The patent replaces traditional mechanical fabrication methods (cutting, stacking, assembling laminations) with additive manufacturing technology, which builds the stator core layer by layer through material deposition and selective removal, significantly simplifying the manufacturing process
2Adaptability or versatility
If laminated stator cores are used, then eddy current losses are reduced, but motor geometry flexibility is constrained
Solution Approach 1:
The patent segments the magnetic material at the micro-scale by creating a cellular or porous internal structure within the stator core, which provides electrical insulation between magnetic flux paths while maintaining the integrated monolithic structure needed for geometric flexibility
Solution Approach 2:
The patent applies different material properties or structural characteristics to different regions of the stator core, such as varying the density, porosity, or magnetic material distribution in specific areas to optimize both geometric adaptability and eddy current reduction locally
3Ease of manufacture
If conventional laminated stator cores are used, then magnetic flux alignment is maintained, but cooling integration becomes difficult
Solution Approach 1:
The patent incorporates a porous or cellular internal structure within the stator core that provides channels for coolant flow, enabling efficient heat removal from the magnetic material while maintaining the integrated structure and magnetic flux paths
4Productivity
If individual lamination elements are used, then eddy current insulation is achieved, but production time and labor increase
Solution Approach 1:
The patent combines the functions of multiple individual laminations into a single integrated component, achieving eddy current reduction through internal cellular structures rather than through stacking multiple insulated layers, thereby dramatically reducing production time and labor
Solution Approach 2:
The patent replaces the mechanical stacking and assembly process of multiple laminations with additive manufacturing, which creates the insulating cellular structure within a single monolithic piece, eliminating time-consuming assembly operations while maintaining eddy current reduction
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 method results in a material with high permeability, low coercivity, and high saturation induction, minimizing eddy current losses and enabling efficient cooling, thus improving motor performance and reducing manufacturing complexity.
Implementation Method 1
creating molten alloy droplets...directing the molten alloy droplets to a surface...forming domains with insulated boundaries
Implementation Method 2
introducing one or more reactive gases proximate the in-flight droplets...the one or more reactive gases creates an insulation layer on the droplets
Data Source
Figure 1~2
Figure 3~4
Figure 5A~6
AI summary
A system for forming a soft magnetic bulk material of a motor stator from a magnetic material and a source of insulating material, the system comprising: a support; a heating device; a deposition device; and an indexing mask subsystem. The support is configured to support the soft magnetic bulk material of the motor stator. The heating device is for heating the magnetic material to form particles having a softened state. The deposition device is for depositing successive layers of particles of the magnetic material in the softened state on the support. The indexing mask subsystem is configured as a first negative of an inner shape of the motor stator and a second negative of an outer shape of the motor stator. The indexing mask subsystem is located between the deposition device and the support and indexed relative to the support upon deposition of the successive layers to selectively block the successive layers of particles of the magnetic material in the softened state from being deposited on the support, thus forming the soft magnetic bulk material of the motor stator as the inner shape of the motor stator and the outer shape of the motor stator on the support. The soft magnetic bulk material has a plurality of adhered domains of magnetic material, wherein substantially all of the domains of magnetic material are separated by a predetermined layer of high resistivity insulating material.