Stator Coil Assembly Centering With Folded Insulation Films

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Solution Overview

Problem

Accurate positioning of preformed coil assemblies on stator teeth is difficult, leading to asymmetry in insulation gaps, which affects dielectric insulation and motor lifetime, and existing winding carriers are costly and fragile, limiting production and performance.

Innovation Solution

A preformed coil assembly with winding carriers and insulation films that ensure equal gap widths between the coil and stator teeth, using folded insulation films to center the coil assembly and robust winding carriers that withstand copper wire tension, facilitating efficient manufacturing and improved insulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a winding carrier with thin lateral walls is used to create small gaps for maximum copper filling factor and heat dissipation, then the copper filling factor and heat dissipation are improved, but the winding carrier becomes fragile and limits the winding process in terms of speed and tension

Engineering Contradiction:

Improvecopper filling factorVSAvoidwinding carrier robustness

Core Design Contradiction:

ProductivityVSStrength

Solution Approach 1:

The insulation system is segmented into multiple components: the winding carrier provides structural support, while separate insulation films (first and second insulation films) provide the necessary insulation and gap control. This segmentation allows the winding carrier to be robust without compromising the gap precision.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Insulation films are introduced as intermediary elements between the winding carrier and the stator tooth. These films control the gap dimensions and provide insulation, allowing the winding carrier to maintain structural integrity while achieving the desired small gap for maximum copper filling factor.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Manufacturing precision

If injection technology is used to produce winding carriers with precise thin lateral walls, then the manufacturing precision is improved, but the cost and time required to create a new winding carrier becomes very high

Engineering Contradiction:

Improvelateral wall thickness precisionVSAvoidmanufacturing cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent uses standard, cost-effective manufacturing methods for the winding carrier and relies on inexpensive insulation films to achieve the precise gap dimensions. This approach avoids the need for expensive injection-molded winding carriers with integrated thin walls.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

Insulation films serve as intermediary elements that are easier and cheaper to manufacture with high precision compared to integrating thin walls into the winding carrier itself. These films provide the necessary dimensional control without requiring complex manufacturing processes.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of operation

If manual positioning is used to position preformed coil assemblies on stator teeth, then the ease of operation is improved, but the positioning precision and symmetry of insulation gaps deteriorates

Engineering Contradiction:

Improveassembly simplicityVSAvoidcoil assembly positioning accuracy

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

The insulation films are designed to automatically ensure symmetric positioning when wrapped around the winding carrier. The folding mechanism and superposed portions create self-aligning features that guide the coil assembly into the correct position on the stator tooth without requiring manual adjustment.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The insulation films are pre-formed with specific geometries (folded portions, superposed portions) that predetermined the positioning characteristics. This preliminary preparation ensures that when the coil assembly is installed, the correct positioning and symmetry are achieved automatically.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS12051954B2Preformed coil assembly for a stator of an electric motor, comprising coil centering insulation films

Publication Date: 2024.07.30 ETEL SA

AI summary

A preformed coil assembly for a stator of an electric motor includes first and second winding carriers located on respective opposite ends of the preformed coil assembly and a winding part wound around the winding carriers to form first and second elongated winding portions with an elongated opening therebetween to be fitted around a tooth of a stator. The preformed coil assembly includes first and second insulation films disposed around the first and second winding portions. Each insulation film includes upper and lower folded portions resting against first and second opposite walls of respective winding carriers to provide first and second distances between respective opposite lateral sides of the tooth and a corresponding non-folded portion of respective first and second insulation films. The first and second distances are equal so that the preformed coil assembly is centered with respect to the tooth when mounted therearound.