Stator Winding with Segmented End Winding Angles
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Solution Overview
Problem
Conventional stator windings face challenges in reducing the axial length of coil ends while maintaining a large bending angle without damaging the coating film and insulating members, which limits the occupying area rate and increases thicknesses.
Innovation Solution
The stator winding configuration includes U-shaped conductors with specific bent parts and insertion positions, allowing for a larger bending angle near the slot opening without pressing against the slot edge, achieved by setting the second angle equal to or greater than the first angle and optimizing the axial length and clearance between bent parts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the bending angle of the U-shaped conductor near the slot opening is increased to shorten the axial length of the coil end, then the axial length is reduced, but the coating film and insulating member may be damaged due to pressing against the slot edge
Solution Approach 1:
The end winding is divided into multiple bending sections with different bending angles. The first bending section near the slot opening has a smaller bending angle to avoid pressing against the slot edge, while the second bending section further from the slot has a larger bending angle to achieve coil end shortening. This segmentation allows different parts of the end winding to serve different functions.
Solution Approach 2:
Different bending angles are applied at different locations along the end winding. The bending angle is locally optimized based on the position relative to the slot opening, with smaller angles near the slot to avoid damage and larger angles farther away to reduce axial length. This local quality approach ensures both protection of insulating components and achievement of compact dimensions.
2Reliability
If the thicknesses of the coating film and insulating member are increased to prevent damage, then the reliability is improved, but the occupying area rate is reduced
Solution Approach 1:
The end winding is segmented into multiple bending sections, allowing the conductor to achieve adequate bending angles without requiring excessive thickness of coating or insulation. By distributing the bending across sections, the mechanical stress on any single point is reduced, enabling thinner protective layers while maintaining reliability.
Solution Approach 2:
The bending angle distribution along the end winding is changed from a uniform or single-angle configuration to a multi-section configuration with varying angles. This parameter change allows the system to achieve both protection and compactness without compromising the occupying area rate through excessive insulation thickness.
3Length of moving object
If a large bending angle is used to shorten the axial length, then the axial length is reduced, but the U-shaped conductor is pressed on the slot edge causing damage
Solution Approach 1:
The end winding path is divided into multiple bending sections with progressively increasing bending angles. The first section near the slot opening uses a smaller bending angle to minimize pressing force on the slot edge, while subsequent sections use larger angles to achieve the desired axial length reduction. This segmentation distributes the mechanical load and avoids concentration of stress at the slot edge.
Solution Approach 2:
Instead of using a single large bending angle in one location, the solution distributes the bending across multiple sections along the axial and radial dimensions. This dimensional distribution of the bending path reduces the pressing force at any single point while achieving the overall axial length reduction goal.
Data Source
AI summary
A stator for a rotational electrical machine includes a cylindrical stator core and a stator winding. The stator core includes slots arranged at intervals in a circumferential direction. The slots pass through the stator core in an axial direction. The stator winding is obtained by joining together ends of U-shaped conductors inserted through the slots. A second insertion part is located away from a first insertion part in the circumferential direction and is inserted in its corresponding slot. A joining end part is joined to another U-shaped conductor at a joining position away from the insertion part in the circumferential direction. The joining end part includes a first bent part and at least one second bent part. The first bent part is bent near an opening of its corresponding slot. The second bent part is bent between the first bent part and the joining position.