Electric Machine Cooling Agitator Stator End Turns

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Solution Overview

Problem

Conventional electric machine cooling systems in hybrid vehicles are inefficient in heat removal from electric motors, leading to reduced lifespan and operating efficiency.

Innovation Solution

The electric machine module incorporates an agitator member and a cover to enhance coolant circulation, allowing for a multiple-pass cooling method where coolant is radially slung back onto the stator end turns multiple times, increasing cooling effectiveness and utilizing a stator cavity to concentrate coolant near heat sources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional cooling systems are used, then the structure is simple, but cooling efficiency is insufficient leading to reduced lifespan and operating efficiency

Engineering Contradiction:
Improvelifespan and operating efficiencyVSAvoidcooling system structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The agitator member is positioned within the stator cavity, nesting components within the housing to maximize space utilization. The cover with coolant apertures integrates with the housing structure, creating a compact nested arrangement that improves cooling without proportionally increasing overall system size

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The system uses a coolant fluid circulated through apertures in the cover to cool the stator end turns. The agitator member enhances this hydraulic cooling by radially slinging the coolant back onto the stator end turns, creating multiple-pass coolant contact that significantly improves heat removal efficiency

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Temperature

If coolant contact time is increased, then cooling efficiency improves, but the system requires more complex circulation mechanisms

Engineering Contradiction:
Improvecooling efficiencyVSAvoidcoolant circulation mechanism
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The agitator member, which rotates synchronously with the rotor, uses the rotor's own rotational energy to sling coolant radially outward and back onto the stator end turns. This self-service mechanism creates multiple-pass coolant circulation without requiring additional pumps or complex circulation systems

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The rotating agitator member creates periodic coolant circulation patterns, repeatedly slinging coolant onto the stator end turns as it rotates. This periodic action ensures continuous multiple-pass cooling contact throughout the stator structure

Inventive Principle:
Principle #19Periodic 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 significantly improves cooling efficiency by maximizing coolant contact with heat-generating components, extending the lifespan and enhancing the operating efficiency of electric machines in hybrid vehicles.

Implementation Method 1

coolant circulation... maximizing coolant contact with heat-generating components

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

agitator member and a cover to enhance coolant circulation, allowing for a multiple-pass cooling method where coolant is radially slung back onto the stator end turns multiple times

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP2580852B1Electric machine cooling system and method
Publication Date: 2020.12.16 REMY TECHNOLOGIES LLC
  • EP2580852B1 patent drawingFigure 1~2
  • EP2580852B1 patent drawingFigure 3
  • EP2580852B1 patent drawingFigure 4

AI summary

Embodiments of the invention provide an electric machine module and a method for cooling an electric machine. The electric machine module includes the electric machine including a stator with stator end turns and a housing enclosing the electric machine. An inner wall of the housing defines a machine cavity. The electric machine module also includes a cover coupled to the housing and extending radially inward into the machine cavity. The cover and the stator end turns define a stator cavity which is in fluid communication with the machine cavity.