Stator Core Segmentation for Low Cogging Torque in PM Motors
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Solution Overview
Problem
Existing stator core designs for permanent magnet motors face challenges in balancing low cogging torque and high torque, with previous techniques either increasing cogging torque when thickening teeth coupling portions or struggling to adjust torque effectively with multiple core sheet configurations.
Innovation Solution
A stator core with a stack structure comprising a first core sheet with coupled teeth and no slot openings, and at least two kinds of second core sheets with radially protruded teeth and slot openings, where the slot openings are identical in angle and evenly distributed in the circumferential direction, allowing for low cogging torque and high torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If teeth coupling portions are made thick to reduce cogging torque, then cogging torque decreases, but torque also decreases
Solution Approach 1:
The stator core is divided into multiple core sheets (first core sheet with teeth coupling portions and second core sheets with slot openings) that are laminated together. This segmentation allows different regions to have different functions: the first core sheet provides teeth coupling to reduce cogging torque, while the second core sheets provide slot openings to maintain high torque output.
Solution Approach 2:
Different regions of the stator core are given different properties: the teeth coupling portions in the first core sheet are made thick to reduce cogging torque, while the second core sheets have slot openings in specific regions to maintain torque. This local differentiation resolves the contradiction by optimizing each region for its specific function.
2Object-generated harmful factors
If teeth coupling portions are entirely closed without slot openings to reduce cogging torque, then cogging torque decreases, but device complexity increases
Solution Approach 1:
The stator core is segmented into multiple core sheets with different configurations. The first core sheet has closed teeth coupling portions for reducing cogging torque, while the second core sheets have slot openings. This segmentation allows the system to achieve low cogging torque without requiring the entire structure to be complex and closed.
Solution Approach 2:
The laminated core sheet structure serves multiple functions simultaneously: it reduces cogging torque through the first core sheet's closed teeth coupling portions, maintains torque through the second core sheets' slot openings, and simplifies the overall structure by using standard lamination techniques rather than requiring a completely closed complex structure.
Data Source
AI summary
A stator core includes a first core sheet having a plurality of teeth that is radially protruded outward and a teeth coupling portion that couples the plurality of teeth, and at least two kinds of second core sheets having a plurality of teeth that is radially protruded outward and slot openings that are provided between the plurality of teeth. The first and second core sheets are laminated to form a stack structure, and, in the second core sheets of an identical kind, the slot openings are identical in opening angle and are evenly distributed in a circumferential direction.