Motor Stator Cooling via Segmented Laminations

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Solution Overview

Problem

Conventional air cooling methods for electric motors in environmental control systems, such as those used in aircraft, often fail to provide sufficient cooling during high-speed or high-altitude operating conditions, leading to excessive temperatures that affect reliability and performance.

Innovation Solution

A laminated stator design incorporating conductive lamination layers with high electrical conductivity and separate cooling lamination layers made of annealed pyrolytic graphite, which have high thermal conductivity but low electrical conductivity, to enhance heat transfer and dissipation, thereby facilitating effective cooling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional air cooling methods are used for electric motors, then the motor structure remains simple, but the cooling effectiveness is insufficient under high-speed or high-altitude operating conditions

Engineering Contradiction:
Improvemotor operating temperatureVSAvoidmotor reliability
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The stator is segmented into multiple thin laminations stacked together, with cooling lamination layers inserted between conductive lamination layers. This segmentation allows heat to be conducted through multiple interfaces and dissipated more effectively, resolving the contradiction between maintaining simple structure and achieving sufficient cooling.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The stator uses composite lamination structure combining conductive lamination layers (high electrical conductivity) and cooling lamination layers (high thermal conductivity, low electrical conductivity). This composite material approach allows simultaneous optimization of electrical performance and thermal management, reducing operating temperature while maintaining motor reliability.

Inventive Principle:
Principle #40Composite materials

2Temperature

If cooling lamination layers with high thermal conductivity are added to the stator, then heat transfer and dissipation improve, but the stator structure becomes more complex

Engineering Contradiction:
Improveheat dissipation efficiencyVSAvoidstator structure complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The stator is divided into multiple thin laminations (e.g., 10-50 layers) with cooling lamination layers interspersed among conductive lamination layers. Each lamination is thin (0.1-1.0mm), and the entire stack achieves effective heat dissipation without requiring a single complex cooling structure. This segmentation resolves the contradiction between improved heat transfer and structural complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different lamination layers have different local properties: conductive lamination layers provide electrical conductivity where needed, while cooling lamination layers provide thermal conductivity in specific regions for heat dissipation. This local differentiation allows optimized heat transfer without uniformly increasing complexity throughout the entire stator structure.

Inventive Principle:
Principle #3Local quality

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

The solution effectively reduces operating temperatures from 236.9°C to 211°C under worst-case conditions, improving motor reliability and performance by increasing heat transfer and dissipation through the use of cooling lamination layers.

Implementation Method 1

a second plurality of stator laminations with a second electrical conductivity and a second thermal conductivity, wherein the second electrical conductivity is lower than the first electrical conductivity and the second thermal conductivity is higher than the first thermal conductivity

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

The electric motor of the environmental control system, as well as other motors, may utilize air cooling to cool the motor during operation

Methodology Applied
Scientific EffectConvection cooling: Convection

Data Source

PatentEP3163722B1Environmental control system
Publication Date: 2021.12.29 HAMILTON SUNDSTRAND CORP
  • EP3163722B1 patent drawingFigure 1
  • EP3163722B1 patent drawingFigure 2
  • EP3163722B1 patent drawingFigure 3

AI summary

A laminated stator for a motor includes a first plurality of stator laminations (120) with a first electrical conductivity and a first thermal conductivity, and a second plurality of stator laminations (122) with a second electrical conductivity and a second thermal conductivity, wherein the second electrical conductivity is lower than the first electrical conductivity, the second thermal conductivity is higher than the first thermal conductivity, and the second plurality of stator laminations (122) are disposed throughout the first plurality of stator laminations (120).