Centrally-Distributed Coreless Winding for Counter EMF Optimization

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Solution Overview

Problem

Conventional coreless motor windings face issues with conductor dislocation and inefficient counter electromotive force (EMF) distribution due to limited winding die length and staggered-layer phenomena, leading to reduced EMF utilization and performance.

Innovation Solution

A centrally-distributed coreless winding design with staggered conductors in the middle portion and normal conductors on both sides, where the winding taps are located at the ends of the normal conductors, increasing conductor density in the middle and reducing it towards the sides, with the number of staggered conductors proportional to the inner diameter.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conductors are evenly wound around the winding die, then the winding process is simple, but the counter EMF distribution becomes unbalanced with vectors near the center line being much larger than those on both sides

Engineering Contradiction:
Improvewinding process simplicityVSAvoidcounter EMF distribution balance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies local quality by creating different conductor distribution densities in different regions of the winding. Specifically, the middle portion has a first density while both end portions have a second density that is lower than the first density. This non-uniform distribution optimizes the counter EMF vector balance, making vectors near the center line more comparable to those on both sides, thereby improving overall EMF utilization while maintaining manufacturing feasibility.

Inventive Principle:
Principle #3Local quality

2Power

If the serial turn number per coil or coil diameter increases, then the motor performance improves, but conductor dislocation occurs due to limited winding die length

Engineering Contradiction:
Improvemotor performanceVSAvoidconductor positioning accuracy
Core Design Contradiction:
PowerVSManufacturing precision

Solution Approach 1:

The patent segments the winding into distinct regions: a middle portion and two end portions, each with different conductor densities. This segmentation allows the middle portion to accommodate higher turn numbers for improved performance while the end portions have reduced density to prevent dislocation within the limited winding die length. The segmented approach enables scaling of motor performance without sacrificing manufacturing precision.

Inventive Principle:
Principle #1Segmentation

3Productivity

If staggered-layer phenomenon occurs due to winding machine stroke accuracy, then the winding can be completed, but the even distribution of conductors is compromised reducing EMF utilization

Engineering Contradiction:
Improvewinding completionVSAvoidEMF utilization efficiency
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent changes the density parameter of conductor distribution along the winding length. By setting the middle portion density higher than the end portions, it compensates for the staggered-layer phenomenon caused by winding machine stroke inaccuracies. This parameter change ensures that even with imperfect winding execution, the overall conductor distribution achieves optimal EMF utilization, maintaining both productivity and reliability.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3160016B1Centrally-distributed coreless winding
Publication Date: 2019.05.15 SHANGHAI MOONS ELECTRICAL APPLIANCE
  • EP3160016B1 patent drawingFigure 1~3

AI summary

The present invention relates to a centrally-distributed coreless winding, comprising staggered conductors, normal conductors and winding taps, wherein the staggered conductors are concentrated in the middle of the winding, the normal conductors are distributed on both sides of the staggered conductors and the winding taps are located at both ends of the normal conductors, the density in the middle portion of the winding is greater than that of the normal conductors. Compared with the prior art, the invention effectively raises the counter electromotive force (EMF) of the coreless motor and further improves the performance of the motor.