Segmented Stator Teeth with Potting Retention

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Solution Overview

Problem

Traditional stator designs with a single solid piece limit coil winding space, leading to inefficiencies due to gaps between teeth, poor thermal conductivity, and complex manufacturing processes.

Innovation Solution

Individual stator teeth are wound and radially mounted to a stator back-iron using potting material, allowing for minimized space between coils, improved thermal conductivity, and reduced manufacturing complexity by using an over-moulded insulation layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the entire stator is formed of a single solid piece, then structural strength is improved, but coil winding space is limited causing gaps between coils of adjacent teeth

Engineering Contradiction:
Improvestructural strengthVSAvoidcoil winding space
Core Design Contradiction:
StrengthVSVolume of moving object

Solution Approach 1:

The stator is divided into separate components: individual stator teeth and a stator back-iron. The teeth are pre-formed with coil windings and then assembled to the back-iron using retaining features. This segmentation allows optimal coil placement on each tooth without gaps, while the assembled structure maintains structural integrity.

Inventive Principle:
Principle #1Segmentation

2Reliability

If traditional coil insulation methods are used, then electrical insulation is provided, but thermal conductivity is poor limiting motor performance

Engineering Contradiction:
Improveelectrical insulationVSAvoidthermal conductivity
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The insulation system uses a composite approach: an insulating layer (such as varnish or film) is applied to the coil windings, and then a thermally conductive potting material is applied over the insulation. This composite structure provides both electrical insulation and improved thermal conductivity, allowing heat to be conducted away from the coils while maintaining electrical isolation.

Inventive Principle:
Principle #40Composite materials

3Strength

If large single piece stators are manufactured, then structural integrity is maintained, but manufacturing complexity increases requiring complex winding machines and processes

Engineering Contradiction:
Improvestructural integrityVSAvoidmanufacturing complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The stator is manufactured in segmented parts (teeth and back-iron) that can be produced using simpler, less expensive equipment. The teeth can be formed and wound separately using basic winding machines, then assembled to the back-iron using retaining features. This reduces manufacturing complexity while maintaining structural integrity through the assembled construction.

Inventive Principle:
Principle #1Segmentation

4Device complexity

If individual stator teeth are radially mounted to stator back-iron with potting material, then manufacturing complexity is reduced and weight is decreased, but additional assembly steps are required

Engineering Contradiction:
Improvemanufacturing complexityVSAvoidassembly process
Core Design Contradiction:
Device complexityVSExtent of automation

Solution Approach 1:

The coil windings are applied to the stator teeth in advance, before the teeth are assembled to the back-iron. The retaining features are also pre-formed on the back-iron. This preliminary preparation allows for simpler, more automated assembly processes where pre-prepared components are simply fitted together, reducing overall manufacturing complexity despite the additional assembly step.

Inventive Principle:
Principle #10Preliminary action

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 approach increases coil winding efficiency, reduces weight, and enhances thermal conductivity, enabling higher motor performance and simpler manufacturing.

Implementation Method 1

potting material being used as a retaining feature for retaining the stator tooth to the stator back-iron

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

an insulation layer to be over moulded to the stator tooth prior to the mounting process. The use of an over moulding layer applied to single stator tooth can minimise the risk of any air gaps forming between the insulation layer and the stator tooth, thereby providing an electrical insulation layer between the coils and the stator

Methodology Applied
Scientific EffectElectrical insulation: Dielectric

Implementation Method 3

improving thermal conductivity

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP2909920B1A stator or rotor
Publication Date: 2022.03.30 PROTEAN ELECTRIC LIMITED
  • EP2909920B1 patent drawingFigure 1
  • EP2909920B1 patent drawingFigure 2~3
  • EP2909920B1 patent drawingFigure 2a~2b

AI summary

A stator or rotor for an electric motor or generator comprising a circumferential support having a protrusion; a tooth arranged to receive coil windings, wherein the tooth includes a recess in which is housed the protrusion of the circumferential support, and the protrusion and the recess in the tooth are arranged to have a cavity or channel formed on an adjacent surface of the recess and the protrusion when the protrusion is housed in the recess, wherein a material is placed inside the cavities or channels formed by the adjacent surfaces of the recess and the protrusion for retaining the tooth to the support.