PTO Clutch Pressure Control for Smooth Work Vehicle Engagement

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing control logic for hydraulically actuated clutches in power-take-off assemblies of work vehicles does not account for wear and damage, leading to abrupt engagement, reduced mechanical resistance, and potential operator hazards due to jerks or oscillations.

Innovation Solution

A method and apparatus that utilize a solenoid-controlled proportional hydraulic valve and closed-loop control to modulate hydraulic pressure based on the angular velocity ratio between input and output shafts, ensuring smooth and stepless engagement of the PTO clutch, compensating for wear or damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional control logic is used for the hydraulically actuated clutch, then the structure is simple and cost-effective, but the engagement becomes abrupt and causes jerks or oscillations due to wear and damage over time

Engineering Contradiction:
Improveclutch engagement smoothnessVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The control unit continuously monitors the rotational speed of the PTO shaft and uses this feedback to dynamically adjust the clutch engagement process. By comparing the actual rotational speed with the desired speed, the system can detect wear-induced engagement issues and compensate in real-time, ensuring smooth operation despite clutch degradation over time.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts the clutch engagement parameters based on real-time operational conditions and detected wear patterns. Rather than using fixed engagement control, the system adapts the engagement profile to maintain optimal performance, transitioning from static control to dynamic adaptation as the clutch ages.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If the clutch is engaged without compensation for wear, then the control process is simple, but mechanical resistance decreases and operator safety is compromised due to jerks or oscillations

Engineering Contradiction:
Improvecontrol process simplicityVSAvoidoperator hazard from jerks or oscillations
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The control unit continuously monitors the rotational speed of the PTO shaft and uses this feedback to dynamically adjust the clutch engagement process. By comparing the actual rotational speed with the desired speed, the system can detect wear-induced engagement issues and compensate in real-time, ensuring smooth operation despite clutch degradation over time.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system prepares for potential engagement problems by implementing a controlled, progressive engagement sequence that anticipates wear-related issues. The multi-stage engagement process with monitoring built-in acts as a preventive measure, cushioning against the harmful effects of wear before they can manifest as dangerous jerks or oscillations.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If traditional engagement control is used, then the device is cost-effective, but the clutch may not engage correctly over the useful life of the work vehicle

Engineering Contradiction:
Improveclutch engagement correctnessVSAvoiduseful life of work vehicle
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The control unit continuously monitors the rotational speed of the PTO shaft and uses this feedback to dynamically adjust the clutch engagement process. By comparing the actual rotational speed with the desired speed, the system can detect wear-induced engagement issues and compensate in real-time, ensuring smooth operation despite clutch degradation over time.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts the clutch engagement parameters based on real-time operational conditions and detected wear patterns. Rather than using fixed engagement control, the system adapts the engagement profile to maintain optimal performance, transitioning from static control to dynamic adaptation as the clutch ages.

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

Ensures smooth and progressive engagement of the PTO assembly, preventing jerks and oscillations, and maintaining correct engagement despite wear or damage, optimizing clutch performance over the vehicle's lifetime.

Implementation Method 1

A method and apparatus that utilize a solenoid-controlled proportional hydraulic valve and closed-loop control to modulate hydraulic pressure based on the angular velocity ratio between input and output shafts

Methodology Applied
Scientific EffectHydraulic pressure modulation: Hydraulic Press

Implementation Method 2

A method and apparatus that utilize a solenoid-controlled proportional hydraulic valve

Methodology Applied
Scientific EffectSolenoid actuation: Solenoid

Data Source

PatentEP4407206B1Improved method and apparatus for controlling a power-take-off assembly of a work vehicle
Publication Date: 2025.09.24 CNH IND ITALIA SPA
  • EP4407206B1 patent drawingFigure 1
  • EP4407206B1 patent drawingFigure 2~3
  • EP4407206B1 patent drawingFigure 4

AI summary

There is described method for controlling the engagement of a power-take-off assembly (4) of a work vehicle (1); the power-take-off assembly (4) is coupled to a powertrain assembly (2) of the work vehicle (1) for transmitting torque to a work implement carried by the work vehicle (1); the power-take-off assembly (4) comprises: an input shaft (6) carried by the powertrain assembly (2); an output shaft (8) connectable to the work implement; a power-take-off clutch (10) interposed between the input shaft (6) and the output shaft (8), and adapted to selectively engage the output shaft (8) with the input shaft (6); and electrically actuated valve means (12), which are interposed between the power-take-off clutch (10) and a source of pressurized fluid (16), to control the flow of the pressurized fluid fed towards the power-take-off clutch (10) control its engagement; the proposed method allows to control the engagement of the power-take-off assembly (4) in a progressive manner.