Forage Harvester Flap Hydraulics for Low-Energy Safe Opening

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Solution Overview

Problem

Existing forage harvesters lack a simple and energy-efficient automated mechanism to control the adjustable wear plate, which is crucial for allowing large objects to pass through the processing system during harvesting, and there is a need for an efficient way to manage the flap operation when the prime mover is stopped.

Innovation Solution

A hydraulic circuit with a primary hydraulic pump and a coupled hydraulic charge pump is used to control a controllable flap, which automatically opens when input power is interrupted, utilizing a hydraulic actuator supplied by the charge pump to maintain low energy consumption and ensure safe operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a hydraulic actuator is used to control the controllable flap, then the flap can be automatically controlled to open when power is interrupted, but energy consumption increases

Engineering Contradiction:
Improveautomatic safety functionVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The hydraulic actuator is designed to automatically open the flap when power is interrupted without requiring continuous energy input. The system uses the natural return of hydraulic fluid to the tank to enable automatic opening, making the system self-regulating and energy-efficient while maintaining reliable safety functionality.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The hydraulic actuator operates periodically rather than continuously, only consuming energy when needed to maintain the closed position during operation. When power is interrupted, the system transitions to a passive state where the flap opens automatically without continuous energy consumption, optimizing the energy-use pattern.

Inventive Principle:
Principle #19Periodic action

2Ease of operation

If a dedicated control pump is added to supply the hydraulic actuator, then the flap control is improved, but device complexity increases

Engineering Contradiction:
Improveflap controlVSAvoidhydraulic circuit complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The charge pump is designed to serve multiple functions: it supplies hydraulic fluid to the primary hydraulic pump during operation and also supplies the hydraulic actuator for flap control. This multi-functional design eliminates the need for a separate dedicated control pump, reducing system complexity while maintaining effective flap control capability.

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

Solution Approach 2:

The hydraulic circuit integrates the charge pump function with the existing primary hydraulic system, combining two functions (primary pump supply and actuator supply) into a unified circuit. This merging approach reduces the number of separate components and simplifies the overall hydraulic system architecture.

Inventive Principle:
Principle #5Merging (Combining)

3Productivity

If the flap remains closed during harvesting, then processing efficiency is improved, but the system cannot handle large objects

Engineering Contradiction:
Improveprocessing efficiencyVSAvoidability to handle large objects
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The flap is designed as a dynamic component that can transition between closed and open positions based on operational needs. During normal harvesting, the flap remains closed to maintain processing efficiency. When large objects are detected or the prime mover stops, the system automatically transitions to opening the flap, providing adaptability to handle different object sizes while maintaining high productivity during standard operation.

Inventive Principle:
Principle #15Dynamics

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 system provides a safe and energy-efficient automatic mechanism for the flap to open when the prime mover stops, ensuring the passage of large objects and reducing energy consumption by integrating the charge pump with the primary hydraulic system.

Implementation Method 1

a hydraulic actuator for controlling the position of the controllable flap, wherein the controllable flap is configured to move to its open position when the input power received at the input is interrupted and wherein the hydraulic actuator is supplied with a supply pressure from from the hydraulic charge pump

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 2

If the prime mover (engine) is stopped (stopping hydraulic supply in general) the oil in the flap hydraulic actuator returns to a tank so that the flap (by its weight) can move the hydraulic actuator to open the flap

Methodology Applied
Scientific EffectHydraulic fluid return: Hydraulic Press

Implementation Method 3

the flap (by its weight) can move the hydraulic actuator to open the flap

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP4656031A1A forage harvester
Publication Date: 2025.12.03 AGCO INT GMBH
  • EP4656031A1 patent drawingFigure 1
  • EP4656031A1 patent drawingFigure 2
  • EP4656031A1 patent drawingFigure 3

AI summary

A processing system for a forage harvester comprises a cutting system for cutting crop material, a drive system for driving the cutting system and an accelerator for generating a flow of the cut crop material. A controllable flap is provided along the flow path between the cutting system and the accelerator, having an open position to allow relatively large objects to pass through and a closed position. A hydraulic circuit includes a primary hydraulic pump and a coupled hydraulic charge pump. A hydraulic actuator for controlling the position of the controllable flap is supplied with a supply pressure from the hydraulic charge pump. Furthermore, the flap is configured to move to its open position when the input power to the hydraulic circuit is interrupted. This provides a drive system for the flap with low energy requirement and with safe operation.