Segmented Cooling Fan Shroud Reducing Tip Clearance

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Solution Overview

Problem

Aperture plates in cooling systems of heavy-duty vehicles disrupt air flow due to their knife edge design, leading to increased power requirements, sound emissions, and fuel consumption.

Innovation Solution

A shroud system comprising multiple or single piece sections that fit around the cooling fan to channel air effectively, reducing fan tip clearance and optimizing airflow without increasing fan speed, which can be installed or replaced in existing cooling systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If an aperture plate with a knife edge is used to define the circular opening, then the cost is reduced, but the air flow through the fan is disrupted leading to increased power requirements and fuel consumption

Engineering Contradiction:

ImprovecostVSAvoidpower requirements

Core Design Contradiction:

Ease of manufactureVSUse of energy by moving object

Solution Approach 1:

The shroud is divided into multiple sections that fit together to form a complete circular structure around the fan. This segmented approach maintains the aerodynamic benefits of a continuous shroud while simplifying installation and replacement procedures, as sections can be individually removed and reinstalled without disturbing the entire assembly.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The shroud acts as an intermediary component between the aperture plate and the fan. It modifies the airflow path by providing a smooth transition surface that guides air onto the fan blades, eliminating the disruptive knife edge effect while the aperture plate remains in place.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of manufacture

If an aperture plate with a knife edge is used to define the circular opening, then the cost is reduced, but sound emissions are increased

Engineering Contradiction:

ImprovecostVSAvoidsound emissions

Core Design Contradiction:

Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The shroud serves as an intermediary that intercepts and smooths the airflow before it reaches the fan blades. By eliminating the abrupt knife edge discontinuity, it reduces turbulence-induced noise while allowing the simple aperture plate construction to remain.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Productivity

If fan speed is increased to maintain cooling effectiveness, then cooling performance is improved, but power drain and fuel consumption increase

Engineering Contradiction:

Improvecooling effectivenessVSAvoidfuel consumption

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

The shroud changes the airflow parameters by providing a smooth transition that reduces turbulence and improves air delivery to the fan blades. This allows the fan to operate more efficiently at lower speeds, maintaining cooling effectiveness while reducing power consumption and fuel usage.

Inventive Principle:

Principle #35Parameter changes

4Productivity

If a single piece shroud is used, then airflow efficiency is improved, but installation and replacement complexity increases

Engineering Contradiction:

Improveairflow efficiencyVSAvoidreplacement complexity

Core Design Contradiction:

ProductivityVSEase of repair

Solution Approach 1:

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

The shroud system improves airflow efficiency, reducing engine power drain and noise while maintaining effective cooling at lower engine loads, thus lowering fuel consumption and noise levels.

Implementation Method 1

a shroud is provided that can be installed around the fan to channel air to and away from the fan

Methodology Applied

Scientific EffectAir flow channeling:

Implementation Method 2

The shroud is provided to reduce fan tip clearance between the aperture plate and the fan

Methodology Applied

Scientific EffectClearance reduction:

Data Source

PatentUS8950367B2Cooling fan shroud

Publication Date: 2015.02.10 CATERPILLAR INC

AI summary

A cooling fan shroud comprises multiple, functionally identical sections that form a ring-like structure that completely surrounds the fan when the shroud is installed onto an aperture plate or other structure. The shroud makes the cooling system more efficient by improving air flow at a given fan speed by reducing fan tip clearance, and increasing air flow due through the fan. An alternative, single piece shroud is also provided which can be retrofitted to an existing cooling system.