Stator with Radially Mounted Teeth for High Coil Density

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Solution Overview

Problem

Traditional stators with a single solid piece design have limited space for coil windings, leading to inefficiencies due to gaps between teeth, poor thermal conductivity from insulation methods, and complex winding processes, which hinder motor performance and efficiency.

Innovation Solution

The stator design allows individual teeth to be pre-wound and radially mounted to a back-iron with interlocking features, eliminating the need for additional mounting components and enabling over-moulding for improved insulation and thermal conductivity, thereby increasing coil winding density and reducing manufacturing complexity.

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 space for coil windings is limited

Engineering Contradiction:
Improvestructural strengthVSAvoidspace for coil windings
Core Design Contradiction:
StrengthVSVolume of moving object

Solution Approach 1:

The stator is divided into separate components: a stator back-iron and multiple stator teeth that are radially mounted to it. This segmentation allows the teeth to be individually wound with coils before assembly, maximizing coil winding space, while the back-iron provides the necessary structural strength. The interlocking features between teeth and back-iron ensure structural integrity without requiring a single solid piece.

Inventive Principle:
Principle #1Segmentation

2Reliability

If traditional insulation methods are used between stator and coil windings, then electrical insulation is provided, but thermal conductivity is poor

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

Solution Approach 1:

An overmoulding layer made of composite material is applied to the stator teeth. This composite material provides both electrical insulation and improved thermal conductivity, allowing heat to be efficiently conducted from the coil windings to the stator teeth while maintaining electrical isolation. This resolves the contradiction by using a material that simultaneously provides both insulating and thermally conductive properties.

Inventive Principle:
Principle #40Composite materials

3Reliability

If additional mounting components are used to secure teeth to back-iron, then assembly reliability is improved, but device complexity and weight increase

Engineering Contradiction:
Improveassembly reliabilityVSAvoidmounting complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The mounting features are integrated directly into the stator teeth and back-iron structures. Interlocking features such as protrusions and recesses are formed as part of the tooth and back-iron geometry itself, eliminating the need for separate mounting components like screws or clips. This merging of mounting functionality into the structural components reduces complexity and weight while maintaining assembly reliability.

Inventive Principle:
Principle #5Merging (Combining)

4Ease of manufacture

If a single solid piece stator design is used, then manufacturing is simplified, but winding process complexity increases

Engineering Contradiction:
Improvestator manufacturingVSAvoidwinding process complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The stator teeth are individually wound with coils before being assembled to the back-iron. This preliminary winding action allows for optimized coil placement and reduced winding complexity, as each tooth can be wound independently using simpler equipment. The pre-wound teeth are then easily assembled to the back-iron using the interlocking features, simplifying the overall manufacturing process compared to winding coils on a complete single-piece stator.

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 design minimizes space between coils, enhances thermal conductivity, and simplifies the winding process, resulting in increased flux density, improved motor efficiency, and reduced weight and complexity, while maintaining electrical insulation and thermal performance.

Implementation Method 1

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 while also improving thermal conductivity.

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP2532076B1Stator with radially mounted teeth
Publication Date: 2019.04.10 PROTEAN ELECTRIC LIMITED
  • EP2532076B1 patent drawingFigure 1
  • EP2532076B1 patent drawingFigure 2~2b
  • EP2532076B1 patent drawingFigure 3

AI summary

A stator for an electric motor or generator comprising a circumferential support having a plurality of protrusions circumferentially distributed about the support; and a plurality of teeth arranged to receive coil windings, wherein each tooth includes a recess with interlocking means formed within the recess for engaging with a protrusion mounted on the circumferential support in a radial direction.