Electric Machine Separate Double Ventilation Cooling

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

High-power rotating electrical machines face inefficiencies in cooling due to air losses induced by fans, particularly in machines with integrated exciters, where traditional cooling methods lead to recirculation and inadequate heat dissipation around central windings.

Innovation Solution

The implementation of separate air inlets and outlets, with fans arranged to create distinct air flows between the stator and rotor laminations and the casing, allowing independent control of cooling and minimizing recirculation by using centrifugal or helicocentrifugal fans, and strategically placing air inlets and outlets to optimize convective exchanges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If traditional cooling methods with single air inlet are used, then the structure is simple, but air recirculation occurs and cooling efficiency is reduced

Engineering Contradiction:
Improvecooling efficiencyVSAvoidair inlet structure
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The single air inlet is segmented into two separate air inlets: a first air inlet for the stator and a second air inlet for the rotor. This segmentation allows independent control of air flows to different components, preventing recirculation and improving cooling efficiency without requiring complex additional structures

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The harmful recirculation flow is extracted and eliminated by separating the air inlet paths. The first air inlet draws air for stator cooling while the second air inlet draws air for rotor cooling, extracting the recirculation problem from the system by providing dedicated inlet paths for each cooling circuit

Inventive Principle:
Principle #2Taking out (Extraction)

2Temperature

If fans are installed to create air circulation, then cooling is improved, but air losses induced by fans increase

Engineering Contradiction:
Improvewinding temperatureVSAvoidair losses
Core Design Contradiction:
TemperatureVSLoss of energy

Solution Approach 1:

The fan system is segmented into two independent fans: a first fan coupled to the stator and a second fan coupled to the rotor. Each fan creates air circulation only for its associated component, reducing the total air losses while maintaining effective cooling of windings and preventing temperature rise

Inventive Principle:
Principle #1Segmentation

3Device complexity

If air flows are combined in a single circuit, then the structure is simple, but recirculation between rotor and stator circuits occurs

Engineering Contradiction:
Improveair flow circuitVSAvoidcooling reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The single air flow circuit is segmented into two independent circuits: a first air flow circuit for the stator and a second air flow circuit for the rotor. Each circuit has its own air inlet, fan, and cooling path, eliminating recirculation between circuits while maintaining simple overall structure

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different air flow characteristics are provided for different parts of the machine. The first air inlet and first fan provide optimized air flow for stator cooling, while the second air inlet and second fan provide optimized air flow for rotor cooling, with each circuit tailored to its specific cooling requirements

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

This solution reduces the average temperature of windings and hot spots, enhances cooling efficiency, and eliminates the need for drilling in machines with integrated exciters, while minimizing air recirculation and improving ventilation performance.

Implementation Method 1

the rotor driving two fans arranged so as to create an air circulation from the air inlets to the air outlets

Methodology Applied
Scientific EffectForced Convection: Forced Convection

Implementation Method 2

Thanks to the invention, the average temperature of the winding as well as that of the hot spots of the machine, generally located in the center in a standard machine, are reduced, since cool air can circulate around the central parts of the stator and rotor windings

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP2274816B1Electric machine with separate double ventilation
Publication Date: 2013.10.30 MOTEURS LEROY SOMER
  • EP2274816B1 patent drawingFigure 1
  • EP2274816B1 patent drawingFigure 2
  • EP2274816B1 patent drawingFigure 3~4

AI summary

The present invention relates to a rotary electrical machine comprising a casing (2) at least partially housing a stator (3) and a rotor, this casing comprising air inlets and air outlets, the rotor driving at least two fans (18) positioned in such a way as to create a circulation of air from the air inlets to the air outlets, the fans (18) being positioned on each side of that part of the rotor that interacts with the stator, the air outlets being positioned on each side of the air inlets (52, 63), a first airflow flowing between stator laminations and the casing of the machine and a second airflow flowing through the air gap of the machine, the first and second airflows being formed from distinct respective air intakes of the machine.