Stator Cooling Duct Separator Layout for Uniform Coil Temperature

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Solution Overview

Problem

Conventional separating web elements in electrical machines cause local temperature increases, affecting efficiency and stator service life due to inadequate heat distribution and dissipation.

Innovation Solution

An obliquely oriented separating web element that sweeps over a larger surface area, contacting multiple coils and end faces of the stator carrier, with secure fastening elements to enhance heat exchange and reduce thermal stress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional separating web element is used to interrupt the cooling duct, then the cooling medium flow path is separated, but local temperature increase occurs below the separating web element

Engineering Contradiction:
Improvecooling medium flow path separationVSAvoidlocal temperature increase
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The separating web element is oriented obliquely to the axis of rotation instead of being perpendicular, transforming the geometric arrangement from a single-plane interruption to a three-dimensional configuration that spans multiple coils. This angular orientation allows the separating web element to contact multiple coils (at least two) simultaneously, distributing the thermal load across a larger surface area and preventing localized temperature accumulation while maintaining effective flow path separation.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Device complexity

If the separating web element is oriented perpendicular to the axis of rotation, then the structure is simple, but heat distribution is inadequate and thermal stress increases

Engineering Contradiction:
Improveseparating web element orientationVSAvoidheat distribution
Core Design Contradiction:
Device complexityVSTemperature

Solution Approach 1:

The separating web element is designed with asymmetric orientation relative to the cooling duct, specifically at an angle between 0° and 90° to the axis of rotation. This asymmetric configuration optimizes heat distribution by allowing the separating web element to sweep across multiple coils, creating a more uniform thermal field and reducing concentrated thermal stress points that would occur with symmetric perpendicular orientation.

Inventive Principle:
Principle #4Asymmetry

3Device complexity

If the separating web element contacts only one coil, then the structure is simple, but thermal stress on the separating web element is excessive

Engineering Contradiction:
Improvecoil contact configurationVSAvoidthermal stress resistance
Core Design Contradiction:
Device complexityVSStrength

Solution Approach 1:

The heat dissipation function is segmented across multiple coils by orienting the separating web element to contact at least two coils simultaneously. This segmentation distributes the thermal burden from any single coil across multiple contact points, reducing the thermal stress on the separating web element while maintaining structural simplicity. The separating web element effectively divides the thermal load into multiple zones of heat exchange.

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

Improved temperature distribution and heat dissipation across multiple coils, reducing thermal stress and extending the service life of the electrical machine.

Implementation Method 1

multiple coils of the stator are preferably also contacted by a separating web element in order to distribute and dissipate heat between the coils and the separating web element

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 2

the stator carrier comprising at least one cooling duct for a cooling medium, the at least one cooling duct running in the circumferential direction

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3785352B1Electric machine
Publication Date: 2023.08.23 SCHAEFFLER TECHNOLOGIES AG & CO KG

AI summary

The invention relates to an electric machine (1) comprising: - an axis of rotation (D), - a stator carrier (2), - wherein the stator carrier (2) comprises at least one cooling duct (3, 4, 5) for a coolant medium, wherein the at least one cooling duct (3, 4, 5) runs in the circumferential direction (U), and - a separator element (6) for interrupting the at least one cooling duct (3, 4, 5), - wherein the separator element (6) is arranged on the stator carrier (2), and - wherein the separator element (6) is oriented obliquely with respect to the axis of rotation (D).