Commercial Vehicle Hydraulic Fan Control with Pressure Feedback

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Solution Overview

Problem

Existing hydraulic operating devices for cooling fans in commercial vehicles require additional space and compromise energy efficiency due to the use of multiple hydraulic pumps, particularly when operating at partial load.

Innovation Solution

A hydraulic operating device with a control valve and sensor line for adjusting the hydraulic motor speed based on cooling requirements, utilizing a hydraulic supply with pressure feedback to optimize installation space and efficiency, featuring a 2/2-way proportional valve and optional pressure compensation to maintain consistent fan unit speed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a separate hydraulic pump with constant displacement is used to drive the cooling fan, then the fan can operate reliably, but the installation space increases and energy efficiency decreases

Engineering Contradiction:
Improvecooling fan operation reliabilityVSAvoidinstallation space
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent merges the cooling fan hydraulic drive with the existing main hydraulic system by using a single hydraulic pump that serves both the main hydraulic functions and the cooling fan drive through a common supply line, eliminating the need for a separate dedicated hydraulic pump and reducing installation space

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The hydraulic pump is designed to perform multiple functions: it provides hydraulic fluid for both the main hydraulic system operations and the cooling fan drive, making the system more space-efficient by consolidating functions into a single pump unit

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

2Device complexity

If a hydraulic pump with constant displacement is used, then the system is simpler and more cost-effective, but energy efficiency is compromised particularly at partial load

Engineering Contradiction:
Improvehydraulic system complexityVSAvoidenergy efficiency
Core Design Contradiction:
Device complexityVSUse of energy by moving object

Solution Approach 1:

The patent introduces a control valve in the supply line that dynamically adjusts the hydraulic flow to the hydraulic motor based on cooling requirements, enabling the system to adapt to partial load conditions and improve energy efficiency without requiring a complex variable displacement pump

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

A sensor line with pressure sensor provides feedback about the hydraulic pressure in the supply line to a control unit, which then adjusts the control valve position to optimize energy efficiency while maintaining reliable cooling fan operation under varying load conditions

Inventive Principle:
Principle #23Feedback

3Use of energy by moving object

If a control valve is added to adjust hydraulic flow based on cooling requirements, then energy efficiency improves, but device complexity increases

Engineering Contradiction:
Improveenergy efficiencyVSAvoidcontrol system complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent implements a feedback control system where a pressure sensor monitors hydraulic pressure in the supply line and communicates with a control unit that adjusts the control valve, enabling energy-efficient operation while maintaining manageable system complexity through automated control

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces purely mechanical flow control with an electronically controlled valve system that uses sensor feedback and electronic control logic to optimize hydraulic flow, reducing energy consumption while keeping the overall system complexity manageable through electronic rather than mechanical control mechanisms

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 device adapts to actual cooling needs, enhancing energy efficiency and reducing space requirements by eliminating the need for a separate hydraulic pump, while maintaining consistent cooling capacity.

Implementation Method 1

a sensor line branched off in a supply line between the control valve and the hydraulic motor leads to a pressure control input of the hydraulic supply provided for pressure feedback

Methodology Applied
Scientific EffectHydraulic pressure feedback: Hydraulic Press

Implementation Method 2

a control valve for adjusting a volume flow passing through the hydraulic motor depending on a control signal representing a cooling requirement

Methodology Applied
Scientific EffectPressure control: Valve

Implementation Method 3

a hydraulic motor that drives a fan impeller to generate an axial air flow

Methodology Applied
Scientific EffectHydraulic motor operation: Hydraulic Press

Data Source

PatentEP4273377B1Hydraulic operating device for a cooling fan of a commercial vehicle
Publication Date: 2025.08.13 DEERE & CO
  • EP4273377B1 patent drawingFigure 1
  • EP4273377B1 patent drawingFigure 2

AI summary

Hydraulic operating device (12) for a cooling fan (14) of a commercial vehicle (10), comprising a hydraulic motor (16) and a fan unit (18) driven by the hydraulic motor (16) for generating a cooling airflow (20), a hydraulic supply (38) adjustable according to a pressure feedback with respect to its delivery volume for providing pressurized hydraulic fluid, and a control valve (44) for adjusting a volume flow passing through the hydraulic motor (16) depending on a control signal representing a cooling requirement (46), wherein a sensor line (52) branched off in a supply line (50) between the control valve (44) and the hydraulic motor (16) leads to a pressure control input (54) of the hydraulic supply (38).