E-Machine Sprayer Arrangement for Stator End Winding Cooling

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Solution Overview

Problem

Conventional cooling systems for e-machines are ineffective in managing excessive thermal conditions, limiting the power output due to thermal constraints of stator materials, and are inefficient in delivering cooling fluid to the stator.

Innovation Solution

An e-machine with a housing and rotating group, featuring a plurality of nozzles radially directed towards the stator end windings to atomize and spray a cooling fluid, ensuring comprehensive coverage and efficient heat removal, while being compact and efficiently manufacturable.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional cooling systems are used for the stator, then the structure is simple, but the cooling effectiveness is limited and thermal management is insufficient

Engineering Contradiction:
Improvestator thermal conditionsVSAvoidcooling system effectiveness
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The cooling system is segmented into multiple independent nozzles distributed around the stator circumference, each nozzle independently directing cooling fluid to specific end winding regions. This segmentation allows targeted cooling of hot spots while maintaining overall system simplicity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs hydraulic spraying mechanisms where cooling fluid is delivered under pressure through nozzles to atomize and spray the fluid directly onto the end windings. This pneumatic-hydraulic approach significantly enhances heat transfer efficiency compared to conventional passive cooling

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Temperature

If more cooling fluid is delivered to the stator, then thermal management improves, but the system complexity and part count increase

Engineering Contradiction:
Improvestator thermal conditionsVSAvoidcooling system structure
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The nozzles serve multiple functions: they distribute cooling fluid, direct spray patterns to specific regions, and can be positioned to cover different circumferential zones. This multi-functionality reduces the need for additional specialized components while achieving comprehensive cooling

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system utilizes variable spray parameters including fluid pressure, nozzle orientation angles, and spray pattern distribution to optimize cooling effectiveness. By adjusting these parameters rather than adding components, the system achieves improved thermal management without proportional increases in complexity

Inventive Principle:
Principle #35Parameter changes

3Temperature

If the cooling system is designed for comprehensive end winding coverage, then thermal uniformity improves, but manufacturing and assembly difficulty increase

Engineering Contradiction:
Improvethermal uniformity across end windingsVSAvoidnozzle arrangement assembly
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The circumferential coverage is achieved by segmenting the cooling system into multiple identical nozzles spaced around the stator. Each nozzle handles a specific angular sector, and the modular repetition of identical components simplifies manufacturing and assembly compared to a single complex distributed system

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The nozzles are designed with homogeneous structures and identical mounting configurations, allowing standardized manufacturing processes and simplified assembly procedures. The uniform spacing and orientation of nozzles create consistent thermal coverage while maintaining ease of installation and replacement

Inventive Principle:
Principle #33Homogeneity

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 delivers cooling fluid to the stator, reducing thermal issues, enhancing performance, and maintaining a compact, low-part-count design for efficient manufacturing and operation.

Implementation Method 1

the plurality of nozzles is configured for atomizing a cooling fluid and spraying the cooling fluid

Methodology Applied
Scientific EffectAtomization:

Implementation Method 2

spraying a cooling fluid on respective ones of the plurality of end windings

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

atomizing a cooling fluid and spraying the cooling fluid

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP4300779A1E-machine with a cooling system including sprayer arrangement
Publication Date: 2024.01.03 GARRETT TRANSPORTATION I INC
  • EP4300779A1 patent drawingFigure 1
  • EP4300779A1 patent drawingFigure 2
  • EP4300779A1 patent drawingFigure 3~4

AI summary

An e-machine includes a housing and a rotating group supported for rotation about an axis of rotation within the housing. The e-machine includes a stator with a plurality of end windings. The e-machine further includes a plurality of nozzles that is removably supported by the housing and spaced apart in a circumferential direction about the axis of rotation. The plurality of nozzles is directed generally radially toward the axis of rotation and toward the plurality of end windings for spraying a cooling fluid on respective ones of the plurality of end windings.