Hydraulic Return Line Backpressure Control via Electronic Valve

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Solution Overview

Problem

Existing hydraulic systems lack effective active control over backpressure, relying on crude or fixed counter-pressure mechanisms that do not adapt to varying operational conditions, leading to inefficiencies and performance limitations.

Innovation Solution

The implementation of an electronically-controlled counter-pressure valve, controlled by a unit that adjusts return line pressure based on multiple inputs such as prime mover speed, pump flow, and functional commands to hydraulic loads, allowing for dynamic backpressure management to optimize performance and efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If no backpressure control or fixed counter-pressure valve is used, then the system structure is simple, but the controllability and performance are poor

Engineering Contradiction:
Improvebackpressure controllabilityVSAvoidsystem structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent applies dynamics by transitioning from fixed backpressure control to dynamic control. The counter-pressure valve is equipped with a control unit that receives multiple inputs (prime mover speed, pump flow, functional commands) and actively adjusts the backpressure in real-time, allowing the system to adapt to varying operational conditions rather than maintaining a static pressure setting.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements feedback control by using a control unit that monitors system parameters (prime mover speed, pump flow, functional commands) and uses this information to actively adjust the counter-pressure valve. This closed-loop feedback mechanism enables the system to maintain optimal backpressure levels based on actual operating conditions, resolving the contradiction between simple structure and effective controllability.

Inventive Principle:
Principle #23Feedback

2Reliability

If high backpressure is maintained to improve controllability and reduce cavitation, then pumping requirements are reduced, but energy efficiency decreases due to continuous high pressure

Engineering Contradiction:
Improvecavitation resistanceVSAvoidpumping energy
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The control system dynamically adjusts backpressure levels based on real-time operational needs. When cavitation risk is detected or during operations requiring high backpressure (lowering loads), the system increases pressure. During other operations where lower pressure suffices, the backpressure is reduced, thereby minimizing energy consumption while maintaining reliability when needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the backpressure parameter dynamically rather than maintaining a constant high value. The control unit adjusts pressure levels based on multiple inputs including prime mover speed, pump flow, and functional commands, allowing the system to optimize the balance between cavitation resistance and energy efficiency by varying pressure according to actual operational requirements.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If high backpressure is used to improve make-up flow through anti-cavitation valve, then controllability improves, but overall system efficiency decreases during operations not requiring high pressure

Engineering Contradiction:
Improvelowering load controllabilityVSAvoidsystem efficiency
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The system dynamically adjusts backpressure based on the specific operational phase. During lowering operations, high backpressure is maintained to improve controllability and enable regenerating flow through the anti-cavitation valve. During other operations such as lifting or idle states, the backpressure is reduced to minimize energy losses and improve overall system efficiency.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control system applies periodic adjustment of backpressure levels corresponding to different operational cycles. The control unit receives functional commands and adjusts pressure accordingly, applying high backpressure only during periods when lowering operations are performed, and reducing pressure during other operational periods, thereby optimizing both controllability and efficiency.

Inventive Principle:
Principle #19Periodic 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

This solution enables improved controllability and productivity by adjusting backpressure according to specific operational needs, reducing cavitation and pumping requirements, and enhancing overall system efficiency by actively managing pressure in response to varying conditions.

Implementation Method 1

an electronically-controlled counter-pressure valve (60) which enables backpressure in a return line (36) of the system to be varied by a control unit (64)

Methodology Applied
Scientific EffectBackpressure control: Pressure Gradient

Data Source

PatentEP2652341B1Hydraulic system with return pressure control
Publication Date: 2014.12.03 PARKER HANNIFIN CORP
  • EP2652341B1 patent drawingFigure 1
  • EP2652341B1 patent drawingFigure 2
  • EP2652341B1 patent drawingFigure 3

AI summary

A hydraulic system (10) includes an electronically-controlled counter-pressure valve (60) that enables backpressure in a return line (36) of the system to be varied by a control unit (64). The system allows active control of the pressure in the return line to produce different return pressures for different situations. A higher return line pressure may be set to improve make-up or recirculating flow through an anti-cavitation valve (50). This may improve controllability of functions that benefit from backpressure, such as lowering loads (12). The control unit that controls the counter-pressure valve may take into account any of a wide variety of possible inputs when setting the counter-pressure valve.