Cooling Fan Shaking Control for Heat Exchanger Self-Cleaning

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Solution Overview

Problem

Existing cooling devices for motor vehicles, especially in agricultural and construction site operations, face challenges with dust and dirt accumulation, which reduce air throughput and performance, and current self-cleaning mechanisms are inadequate due to lack of vibrations and mechanical coupling.

Innovation Solution

A cleaning process that utilizes a vibration movement induced by the electric drive engine to shake off contaminants from the cooling device, including the heat exchanger, drive engine, and fan wheel, with specific frequency ranges and amplitudes to effectively remove dust, insects, and plant parts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the fan is rigidly connected to the engine's crankshaft, then the fan can be driven reliably, but reversing the fan's rotation direction to blow out contaminants is not possible

Engineering Contradiction:
Improvefan drive reliabilityVSAvoidfan rotation direction control
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The connection between the fan and drive source is segmented into two independent parts: a drive mechanism that provides reliable power transmission, and a controllable coupling mechanism (such as a controllable coupling or differential mechanism) that enables rotation direction reversal. This segmentation allows each part to optimize its function independently.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

An intermediary mechanism (controllable coupling, differential, or variable geometry mechanism) is introduced between the engine crankshaft and fan. This intermediary decouples the rigid direct connection while maintaining reliable power transmission, and simultaneously enables rotation direction control through its own actuation system.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If combustion engine vibrations are used for self-cleaning, then larger particles can be removed, but low-frequency vibrations in electric motor-driven vehicles do not generate sufficient cleaning effect

Engineering Contradiction:
Improvecontaminant removal capabilityVSAvoidvibration frequency and intensity
Core Design Contradiction:
Object-affected harmful factorsVSQuantity of substance

Solution Approach 1:

The invention intentionally generates mechanical vibrations at specific frequencies (including resonance frequencies) to optimize contaminant removal. Unlike passive combustion engine vibrations, the system actively controls vibration frequency and amplitude to match the resonant characteristics of the fan-radiator assembly, maximizing cleaning effectiveness for both light and heavy contaminants.

Inventive Principle:
Principle #18Mechanical vibration

Solution Approach 2:

The vibration parameters (frequency, amplitude, duration) are dynamically adjusted based on operating conditions and contaminant types. The control system modifies these parameters to achieve resonant vibration of the cooling system components, enhancing the cleaning effect even at lower frequencies typical of electric motor-driven vehicles.

Inventive Principle:
Principle #35Parameter changes

3Temperature

If the cooling device operates continuously at high speed, then cooling performance is maintained, but contaminants accumulate more rapidly on the heat exchanger and fan

Engineering Contradiction:
Improvecooling performanceVSAvoidcontaminant accumulation rate
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The system implements periodic cleaning cycles during normal operation. At predetermined intervals or based on contaminant detection, the fan rotation is temporarily reversed or vibration is applied for a short duration to remove accumulated contaminants, then normal cooling operation resumes. This periodic action prevents significant contaminant buildup without compromising overall cooling performance.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The cleaning function is integrated into the continuous cooling operation rather than being a separate intermittent process. The control system continuously monitors cooling performance and contaminant levels, automatically initiating cleaning actions when needed, ensuring that the useful cooling action continues uninterrupted while maintaining cleanliness.

Inventive Principle:
Principle #20Continuity of useful 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

The vibration-based cleaning process effectively removes contaminants without external intervention, maintaining cooling performance and reducing the need for manual cleaning, while also being compatible with existing cooling device components.

Implementation Method 1

controlling the current supply to the drive motor (12) to generate a shaking movement of the heat exchanger (11), the drive motor (12) and/or the fan wheel (14)

Methodology Applied
Scientific EffectVibration: Vibration

Implementation Method 2

The shaking movement serves to shake off and/or loosen contaminants (such as dust, insects and/or plant parts) from the cooling device

Methodology Applied
Scientific EffectResonance: Resonance

Implementation Method 3

The shaking movement serves to shake off and/or loosen contaminants (such as dust, insects and/or plant parts) from the cooling device

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP4405575B1Method for cleaning a cooling device by shaking
Publication Date: 2025.04.30 MAN TRUCK & BUS SE
  • EP4405575B1 patent drawingFigure 1
  • EP4405575B1 patent drawingFigure 2
  • EP4405575B1 patent drawingFigure 3

AI summary

The invention relates, inter alia, to a method for cleaning a cooling device (10) for a motor vehicle (20), wherein the cooling device (10) comprises a heat exchanger (11), an electric drive motor (12) connected to the heat exchanger (11), and a fan wheel (14) which is connected in terms of drive to the drive motor (12). The method comprises operating the cooling device (10) in a shaking mode, the shaking mode comprising controlling a current feed of the drive motor (12) in order to generate a shaking movement of the heat exchanger (11), the drive motor (12) and/or the fan wheel (14). The shaking movement preferably serves here for shaking off contaminants (e.g. dust, insect and/or plant parts) from the cooling device (10). Furthermore, the invention also relates to a cooling device (10) having a control unit (15) which is designed to carry out the method, and to a motor vehicle (20) having such a cooling device (10).