Modular Stator Radial Walls for Air Gap and Thermal Stability

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Solution Overview

Problem

Existing electric motor stator structures face challenges in maintaining a low and constant air gap while accommodating manufacturing tolerances and ensuring mechanical and thermal stability, which can lead to performance degradation and increased costs.

Innovation Solution

The stator module design features a central orthoradially wound winding with two lateral poles, radial walls with central recesses for mechanical and thermal stability, and relief zones for maintaining a constant air gap and enhanced heat dissipation, allowing for modular assembly and independent extraction of modules.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If radial walls are made rigid to ensure mechanical stability, then structural strength is improved, but thermal dissipation capability deteriorates

Engineering Contradiction:
Improvemechanical stabilityVSAvoidheat dissipation
Core Design Contradiction:
StrengthVSTemperature

Solution Approach 1:

The radial walls incorporate a through-channel forming a cooling circuit, creating a porous-like structure that allows fluid circulation. This enables heat dissipation while maintaining the overall structural integrity and mechanical stability of the rigid radial walls.

Inventive Principle:
Principle #31Porous materials

2Manufacturing precision

If stator modules are tightly fixed to minimize air gap, then magnetic coupling is improved, but accommodation of manufacturing tolerances deteriorates

Engineering Contradiction:
Improveair gap constancyVSAvoidtolerance accommodation
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The relief zones on the radial walls provide controlled radial play that allows the stator modules to be positioned at a slightly increased distance from the rotor. This parameter change accommodates manufacturing tolerances while the equiangular distribution maintains acceptable magnetic coupling.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If stator modules are designed with single pole orientation, then field generation is simplified, but field closure through rotor deteriorates

Engineering Contradiction:
Improvewinding arrangementVSAvoidfield closure
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

Each stator module is segmented into two symmetrical portions relative to the radial direction, with each portion carrying a winding and forming a pole. This segmentation allows the magnetic field to be properly closed through the rotor while maintaining a relatively simple winding arrangement on each portion.

Inventive Principle:
Principle #1Segmentation

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 ensures mechanical stability, efficient heat dissipation, and maintains a constant air gap, improving the motor's performance and reliability while accommodating manufacturing tolerances and allowing for high-frequency operation.

Implementation Method 1

each module carries a winding capable of generating a magnetic field

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

the radial walls offer good mechanical stability thanks to their possibility of deformation in the orthoradial direction, the presence of said central recess guaranteeing mechanical flexibility and providing a space allowing a fluid to circulate inside the radial walls

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

providing a space allowing a fluid to circulate inside the radial walls

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP2812981B1Electrical machine having a modular stator structure
Publication Date: 2020.07.01 NOVATEM
  • EP2812981B1 patent drawingFigure 1
  • EP2812981B1 patent drawingFigure 2~3
  • EP2812981B1 patent drawingFigure 4~5

AI summary

An electrical machine (1), the stator of which comprises a chassis (2), and a plurality of stator modules (5) arranged on said chassis (2) at equal angles, each module (5) comprising a winding (9) that can generate a magnetic field, characterised in that each stator module (5) comprises: a central portion (20) on which said winding (9) is orthoradially wound; two side portions (21, 22) each forming a pole (33, 34) oriented towards the rotor, said chassis (2) comprising a plurality of radial walls (3) cooperating with the outer faces (31, 32) of the side portions (21, 22) of said stator modules to hold them in position. Figure