Laminated Core Cover Structure for Torque Ripple Reduction
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Solution Overview
Problem
Rotating electrical machines experience undesirable torque ripple due to the design of grooves in the laminated core, which can lead to a loss of torque and reduced performance, especially in asynchronous machines.
Innovation Solution
The design incorporates at least two spaced-apart taper regions in the cover unit of the laminated core's grooves, allowing for improved magnetic flux guidance without skewing the grooves, thereby reducing torque ripple and enhancing performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the grooves in the laminated core are designed with uniform thickness cover unit, then the manufacturing is simple, but torque ripple occurs due to magnetic flux concentration at the groove roots
Solution Approach 1:
The cover unit is designed with varying thickness: thicker at the groove roots and thinner at the groove openings. This local variation in geometry allows the cover unit to guide magnetic flux away from the groove roots, reducing magnetic flux concentration and the resulting torque ripple, while maintaining structural integrity where needed.
2Object-generated harmful factors
If skewing of grooves is applied to reduce torque ripple, then torque ripple decreases, but the external dimensions and performance of the machine are compromised
Solution Approach 1:
Instead of skewing the entire groove structure, the invention applies local geometric variation only to the cover unit thickness. This targeted approach reduces torque ripple through improved magnetic flux guidance while preserving the overall groove alignment and machine performance characteristics.
Solution Approach 2:
The cover unit is segmented into regions of different thicknesses along its length. This segmentation allows independent optimization of different sections: the thicker portion at the groove roots provides structural support and guides flux, while the thinner portion at the openings reduces flux concentration, achieving torque ripple reduction without affecting overall machine dimensions.
3Object-generated harmful factors
If the cover unit material is made thinner in the radial direction at groove regions, then magnetic flux guidance is improved and torque ripple is reduced, but the structural strength of the cover unit decreases
Solution Approach 1:
The cover unit thickness is optimized locally: thicker at the groove roots where structural strength is critical and magnetic flux guidance is needed, and thinner at the groove openings where flux concentration causes torque ripple. This localized variation achieves both strength and performance requirements.
Solution Approach 2:
The cover unit may be constructed using composite material structures or reinforced geometries that provide enhanced strength-to-weight ratio, allowing reduced thickness in certain regions while maintaining overall structural integrity and mechanical properties.
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 effectively reduces torque ripple and increases the performance of rotating electrical machines without altering their external dimensions, improving resilience and efficiency.
Implementation Method 1
The cover unit has at least one tapered region in a region of a respective groove, in which a material of the cover unit is thinner in a radial direction of the laminated core than in a region of the cover unit adjacent to this tapered region
Data Source
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AI summary
The invention relates to a laminated core (16, 34) for a rotor (14) and/or a stator (12) of a rotating electric machine (140) which has an air gap (20), the laminated core comprising: - teeth (22, 24), which are mutually adjacent in a peripheral direction (56) of the laminated core (16, 34) and delimit grooves (26, 32) for receiving electrical conductors (36, 38) which form a winding; and - a cover unit (42), which is arranged on the air gap side and delimits the grooves (32) in the radial direction, wherein: - the cover unit (42) has, in a region of each groove (32), at least one tapered region (46) in which the material of the cover unit (42) is thinner in a radial direction of the laminated core (16) than in an adjoining region (48); - at least two tapered regions (50, 52), which are mutually spaced apart in the peripheral direction (56) of the laminated core (16), are formed in the region of each groove (32).