Centrifugal Fan Motor Cooling via Helical Vortex

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Solution Overview

Problem

Existing centrifugal fan cooling systems are inefficient, particularly for closed motors and harsh operational conditions, failing to maintain optimal temperatures and extend product lifetime.

Innovation Solution

A centrifugal fan with a cooling system that combines tangential and axial air flow components to create a helical vortex, utilizing an impeller and radial blades to generate a tangential component and an annular channel for an axial component, effectively removing heat from the motor without direct exposure to forced cooling air.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a closed motor is used to improve reliability under harsh conditions, then motor protection is improved, but heat removal efficiency deteriorates

Engineering Contradiction:
Improvemotor reliabilityVSAvoidheat removal efficiency
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The cooling system is segmented into multiple functional zones: an annular channel for axial flow, radial blades for tangential flow generation, and a helical vortex path. This segmentation allows the closed motor to be cooled through internal circulation without direct exposure to external air, maintaining both reliability and cooling efficiency

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary cooling circuit that circulates air through the motor housing internally. This intermediary system acts as a mediator between the closed motor and the external environment, allowing heat removal without compromising motor protection or reliability

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If traditional cooling systems are used to simplify the structure, then device complexity is reduced, but cooling performance deteriorates

Engineering Contradiction:
Improvecooling system structureVSAvoidcooling performance
Core Design Contradiction:
Device complexityVSTemperature

Solution Approach 1:

The impeller serves multiple functions: it drives the main air flow for fan operation and simultaneously generates tangential flow through radial blades to create the helical vortex for cooling. This multi-functionality improves cooling performance without adding separate cooling components, maintaining structural simplicity

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

Solution Approach 2:

The cooling system utilizes dynamic helical vortex flow generated by the rotating impeller and radial blades. This dynamic flow pattern enhances heat removal efficiency compared to static cooling structures, achieving better cooling performance without increasing structural complexity

Inventive Principle:
Principle #15Dynamics

3Temperature

If direct forced cooling air flow is applied to the motor to improve heat removal, then cooling efficiency is improved, but motor reliability deteriorates

Engineering Contradiction:
Improvecooling efficiencyVSAvoidmotor reliability
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The cooling air flow is directed locally through specific paths: axial flow through the annular channel and tangential flow through radial blades. This localized controlled cooling ensures efficient heat removal from critical motor areas without exposing the entire motor to direct forced air flow that could compromise reliability

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 cooling system extends motor lifetime by over 30,000 hours, reduces noise and fluid dynamic noise, and minimizes costs by enhancing heat removal efficiency and eliminating the need for connecting ducts, while maintaining performance.

Implementation Method 1

a centrifugal fan (1) provided with a cooling system for removing heat from the electric motor (3) by means of a flow (RF) of cooling air which is pushed, from an over-pressure generated by an impeller (4), from the inside of the casing (2) towards the outside

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 2

The cooling system comprises a collar (28) integral with the impeller (4) and extending axially from the impeller (4) towards the motor (3), outside of it, and a plurality of radial blades (29) supported by the collar (28) and facing the motor (3)

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP2758671B1Centrifugal fan.
Publication Date: 2015.03.25 SPAL AUTOMOTIVE
  • EP2758671B1 patent drawingFigure 1~2
  • EP2758671B1 patent drawingFigure 3~4
  • EP2758671B1 patent drawingFigure 5

AI summary

Described is a centrifugal fan (1) comprising a centrifugal impeller (4) rotatable around an axis of rotation (R); a drive motor (3) of the centrifugal impeller (4); a casing (2) comprising a central portion (17) for housing the motor (3) and the centrifugal impeller (4) and a tangential outlet channel (18) in communication with the central portion (17); the casing (2) has an inlet opening (15) in the central portion (17) and an outlet opening (16) in the tangential outlet channel (18); the fan (1) comprises a system (4,14, 28, 29) for cooling the motor (3) comprising the impeller (4), a ventilation channel (31) operating between the tangential outlet channel (18) and the central portion (17) for generating a flow of cooling air, a collar (28) integral with the centrifugal impeller (4) extending axially from the centrifugal impeller (4) around the motor (3) and a plurality of blades of the motor (3) for generating a tangential cooling component which combines with the flow of cooling air generating as a resultant a helical vortex around the motor (3).