Single Segment Rotor with Demagnetized Inner Section
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Solution Overview
Problem
The design and manufacture of single-segment rotors for electric motors with flux concentration face challenges such as high manufacturing costs, complicated assembly, and magnetic short-circuiting issues due to the need for individual laminated core segments, which complicates series production and torque transmission.
Innovation Solution
A single-segment rotor design featuring a stack of laminations with star-shaped segment sections and reduced magnetic permeability inner sections, allowing for magnetic isolation and reduced manufacturing effort, where permanent magnets are inserted into form-fitting magnetic pockets within the laminated core, and the core is impregnated with resin for stabilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If individual laminated core segments are used to avoid magnetic short-circuiting, then magnetic insulation between segments is improved, but the number of components and assembly complexity increase
Solution Approach 1:
The rotor core is divided into multiple laminated core segments arranged in a star shape around the central axis. Each segment is separated from adjacent segments by non-magnetic spacing elements, creating magnetic insulation between segments while maintaining a compact integrated structure. This segmentation approach provides magnetic isolation without requiring completely separate components for each segment.
Solution Approach 2:
Non-magnetic spacing elements are introduced as intermediary components between adjacent laminated core segments. These spacing elements serve as magnetic insulators that prevent magnetic flux from short-circuiting between segments, while also providing mechanical spacing and support. This intermediary approach achieves magnetic insulation with minimal additional complexity.
2Ease of manufacture
If complete rotor laminations with connected inner laminations are used, then mechanical stability and ease of production are improved, but magnetic short-circuiting between segments occurs
Solution Approach 1:
The laminated core segments are designed with non-magnetic spacing elements at specific locations where magnetic insulation is required - namely between adjacent segments. The inner laminations remain connected for mechanical stability, but localized non-magnetic barriers are introduced at segment interfaces to prevent magnetic short-circuiting. This local modification approach maintains overall structural integrity while eliminating harmful magnetic coupling.
3Manufacturing precision
If individual sheet metal segments are used to achieve low-scatter structure, then manufacturing precision is improved, but manufacturing costs increase
Solution Approach 1:
Multiple individual laminated core segments are combined into a single integrated rotor assembly with a common central axis and shared non-magnetic spacing elements. This merging approach maintains the manufacturing precision benefits of individual segments (low scatter in magnetic properties) while reducing overall component count and assembly complexity compared to completely separate segment constructions.
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 design achieves a low-scatter rotor structure with reduced manufacturing costs and increased mechanical stability, ensuring magnetic insulation between segments and improved torque transmission without additional components, while allowing for series production and enhanced performance.
Implementation Method 1
The inner side, which is surrounded by the closed annular inner section, is demagnetized, that is to say, its magnetic permeability is reduced
Implementation Method 2
elements can be diffused into the respective inner section, as a result of which a gamma structure (cubic face-centered lattice) is set in the affected area
Implementation Method 3
The laminated core including the permanent magnets can be impregnated with a resin. This not only protects the single-segment rotor against external influences, but also additionally stabilizes it.
Data Source
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AI summary
The manufacturing of high-precision single-segment rotors is to be simplified. For this purpose, a single-segment rotor is provided whose laminated core is made of individual laminations, each of which has several star-shaped segment sections (1) that are largely separated from one another by magnetic recesses for permanent magnets (8). Furthermore, each individual lamination has a central recess for a shaft (9), the central recess being surrounded by a closed annular inner section (2') formed integrally with the respective individual lamination. The magnetic permeability of the inner section (2') is reduced compared to the magnetic permeability of the segment sections (1).