Multilayered Wound Coil Stator Reducing Potential Difference
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Solution Overview
Problem
Existing methods for winding rectangular conductors in multilayer coils for motors face challenges such as potential difference issues leading to thick insulating coatings, which reduce space factor and output power, and complex winding devices that cause heat resistance differences and inefficiencies.
Innovation Solution
A stator coil configuration with a first row wound from an outer layer to an inner layer, a second row from an inner layer to an outer layer, and a third row from an outer layer to an inner layer, incorporating bridging portions to connect rows and reduce potential differences, thereby minimizing insulating coating thickness and improving space factor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a rectangular conductor is used for a coil to improve space factor, then the space factor is improved, but it is hard to wind the rectangular conductor in a coiled form due to its wide cross-sectional area
Solution Approach 1:
The rectangular conductor is divided into multiple segments along its length, with each segment having a specific width. This segmentation allows the conductor to be wound in a coiled form while maintaining the space factor benefits of rectangular conductors. The segmented structure enables proper layering and positioning during the winding process.
Solution Approach 2:
Different portions of the rectangular conductor are designed with different local properties. Specifically, the conductor has a wide cross-sectional area for improving space factor, but incorporates retaining portions with specific dimensional characteristics (e.g., 5mm width, 10mm length) that facilitate winding and positioning. This local quality variation resolves the contradiction between space factor and winding ease.
2Power
If a rectangular conductor with wide cross-sectional area is used to increase current density, then current density is increased, but eddy current problems arise
Solution Approach 1:
The rectangular conductor is segmented into multiple sections along its length, with each segment having optimized dimensions. This segmentation reduces the effective path for eddy currents while maintaining the overall current-carrying capacity and space factor. The segmented structure allows current to distribute more effectively across multiple paths.
Solution Approach 2:
The conductor dimensions are optimized with specific parameters: a wide cross-sectional area for high current density, but with controlled length and width ratios. The retaining portions have specific dimensional parameters (5mm width, 10mm length) that change the electrical characteristics to reduce eddy current effects while maintaining mechanical integrity and winding feasibility.
3Manufacturing precision
If retaining portions are added to prevent displacement during winding, then displacement is prevented, but device complexity increases
Solution Approach 1:
Rather than making the entire conductor complex, retaining portions are added only at specific locations where positioning is needed. These retaining portions have simple geometric features (rectangular protrusions or recesses) with standardized dimensions (5mm width, 10mm length) that provide precise positioning without excessive complexity. The local quality approach adds complexity only where necessary.
Solution Approach 2:
The retaining portions on the conductor are designed to self-align with corresponding features on the stator core or adjacent conductors. This self-aligning mechanism eliminates the need for complex external positioning devices or mechanisms. The conductor's own structure provides the positioning function, reducing overall system complexity.
4Reliability
If thick insulating coating is applied to withstand potential difference, then insulation reliability is improved, but space factor decreases
Solution Approach 1:
The insulating coating is applied in a segmented manner, with thicker insulation only at critical locations where potential difference is highest (such as at retaining portions and layer interfaces). In other areas, thinner insulation suffices. This segmented insulation strategy maintains reliability where needed while minimizing the overall space consumed by insulation.
Solution Approach 2:
The insulating coating thickness varies locally based on the electrical stress requirements. Critical areas with high potential difference (retaining portions, layer boundaries) receive thicker coating for reliable insulation. Non-critical areas receive minimal insulation thickness. This local quality variation optimizes the balance between insulation reliability and space factor.
Data Source
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AI summary
Disclosed are a multilayered wound coil, a stator, and a manufacturing method therefor. The stator is provided with: a stator core comprising laminated steel sheets; and a coil which is wound around a teeth section formed on the stator core and has a plurality of layers formed in the circumferential direction of the stator core. The winding of the coil proceeds in either the radial direction or the circumferential direction of the stator core, whichever direction has fewer adjacent conductors, and doubles back at the end in said direction. This reduces the difference in potential between adjacent conductors, making it possible to ensure insulation between adjacent conductors even with a thinner insulating film.