Multi-Fan Pitch Control Using a Single Mechanical Actuator

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Solution Overview

Problem

Existing cooling systems for large work machines, such as combine harvesters, require complex and expensive hydraulic or pneumatic systems to control the blade pitch of multiple cooling fans, which are technically intricate and costly.

Innovation Solution

A cooling fan assembly with adjustable pitch fans, actuated by a single mechanical actuator through a control member and adjustment mechanisms, eliminating the need for additional hydraulic, pneumatic, or electrical connections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If separate hydraulic or pneumatic control lines are used for each fan, then the blade pitch of multiple fans can be controlled, but the system complexity and cost increase significantly

Engineering Contradiction:
Improveblade pitch controlVSAvoidcontrol system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges the control of multiple fans into a single integrated system. A single hydraulic or pneumatic actuator controls the blade pitch of all fans simultaneously through a common control rod that connects to the pitch adjustment mechanism of each fan. This eliminates the need for separate control lines for each fan, reducing system complexity while maintaining full adaptability of blade pitch control.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The control rod serves as a universal control element that performs the function of controlling blade pitch for multiple fans simultaneously. This single component replaces multiple individual control lines, providing multi-functional capability while simplifying the overall system architecture.

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

2Adaptability or versatility

If separate control lines are used for each fan, then individual pitch adjustment is possible, but the manufacturing cost increases

Engineering Contradiction:
Improvepitch adjustment capabilityVSAvoidmanufacturing cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

By merging the control lines into a single shared hydraulic or pneumatic circuit that controls all fans through one actuator, the number of components requiring manufacturing and assembly is reduced. This lowers manufacturing costs while preserving the ability to adjust pitch for each fan through the common control mechanism.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If hydraulic or pneumatic systems are used, then reliable pitch control is achieved, but sealing requirements and leakage risks increase

Engineering Contradiction:
Improvepitch control reliabilityVSAvoidsealing system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent reduces the number of sealing points by consolidating multiple separate hydraulic or pneumatic control lines into a single control circuit. With only one actuator and one control rod instead of multiple separate systems, the total number of sealing elements required is minimized, reducing leakage risks while maintaining reliable pitch control through the shared hydraulic or pneumatic system.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4450822B1A cooling fan assembly
Publication Date: 2026.02.25 CNH IND BELGIUM NV
  • EP4450822B1 patent drawingFigure 1
  • EP4450822B1 patent drawingFigure 2
  • EP4450822B1 patent drawingFigure 3

AI summary

The fan assembly (1) comprises two or more axial flow fans (2) rotatably mounted on a support structure. The fans are of the adjustable pitch type, i.e. each fan includes a pitch adjustment mechanism that is actuatable by axially shifting a positioning rod (7) extending outward from the hub of the fan. The assembly further comprises a control member (15) and a plurality of adjustment mechanisms (9,34) coupled respectively to the positioning rods (7) and to the control member (15) in such a way that the position of the control member determines the axial position of the positioning rods (7) and thereby the pitch of the blades (6) of all the fans of the assembly. A single actuator (17,32) is configured to actuate a movement of the control member (15).