Hydraulic Section for Load Sensing Applications

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Solution Overview

Problem

Traditional load sensing hydraulic systems face challenges in regulating power distribution according to external signals or limiting user speed when reaching predefined pressure values, leading to inefficient energy use and potential machine operation compromises.

Innovation Solution

A hydraulic section with a combined 'piston-flow regulating element' system, featuring a main spool, piston, and flow regulating element, allows for flow regulation based on external or internal signals by altering pressure balances across active areas, maintaining constant pressure drop and controlling flow through adjustable millings and control means, such as limiters and solenoid valves.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional load sensing hydraulic systems are used, then the pressure drop is kept substantially constant through a metering orifice, but the system cannot regulate power distribution according to external signals or limit user speed when reaching predefined pressure values

Engineering Contradiction:
Improveability to regulate power distribution according to external signalsVSAvoidenergy efficiency
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The patent introduces an intermediary flow regulating element that acts as a mediator between the metering orifice and the user. This element can be controlled by external signals (such as solenoid valves) or internal conditions (such as alarm pressures) to adjust the flow area dynamically, enabling power distribution regulation without compromising energy efficiency

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The flow regulating element transitions from a static component to a dynamic one that can change its flow area in response to control signals. This dynamic adjustment capability allows the system to adapt power distribution to varying operational requirements while maintaining optimal energy use through precise flow control

Inventive Principle:
Principle #15Dynamics

2Productivity

If flow-sharing architectures are used to overcome pump flow limits, then proportional reduction in flow is achieved for all users, but critical users may experience sudden stopping that compromises machine operation

Engineering Contradiction:
Improveflow delivery under saturation conditionsVSAvoidcontinuous operation of critical users
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies local quality by giving different flow regulation characteristics to different users through the flow regulating element. Critical users can be assigned with flow regulating elements that maintain larger flow areas or have priority control, ensuring their continuous operation even when overall system flow is limited, while non-critical users experience proportional reduction

Inventive Principle:
Principle #3Local quality

3Loss of energy

If a differential piston is used for local pressure control, then maximum working pressure is controlled locally with minimal power dissipation, but the system cannot limit user speed upon reaching predefined pressure values

Engineering Contradiction:
Improvepower dissipation in pressure controlVSAvoidability to limit user speed based on pressure signals
Core Design Contradiction:
Loss of energyVSAdaptability or versatility

Solution Approach 1:

The patent merges the differential piston mechanism with a flow regulating element in a combined assembly. The differential piston maintains minimal power dissipation for pressure control, while the integrated flow regulating element responds to pressure signals from the piston to limit user speed by adjusting flow area, achieving both energy efficiency and speed limitation capability

Inventive Principle:
Principle #5Merging (Combining)

4Adaptability or versatility

If additional components are added for flow regulation and control, then power distribution can be regulated according to signals, but device complexity increases

Engineering Contradiction:
Improveflow regulation capabilityVSAvoidstructural complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines multiple functions into integrated assemblies: the flow regulating element is merged with the piston to form a combined unit, and control means such as solenoid valves are integrated with the hydraulic section. This merging approach enables sophisticated flow regulation and signal response capabilities while minimizing the increase in device complexity through shared structures and compact arrangements

Inventive Principle:
Principle #5Merging (Combining)

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

Enables precise regulation of power distribution to users, optimizing energy use and preventing machine operation compromises by generating infinite speed variations and reducing energy dissipation, while maintaining system compactness and structural simplicity.

Implementation Method 1

regulating element, which generates a pressure drop between a front chamber (30) communicating with the metering orifice (4) and a first distribution bridge (31)

Methodology Applied
Scientific EffectPressure balance: Pascal's Law

Implementation Method 2

a load sensing hydraulic system enables the pressure drop to be kept substantially constant through a metering orifice of a spool valve

Methodology Applied
Scientific EffectPressure drop: Pressure Drop

Data Source

PatentEP2980416B1Hydraulic section for load sensing applications and multiple hydraulic distributor
Publication Date: 2019.06.05 BUCHER HYDRAULICS SPA
  • EP2980416B1 patent drawingFigure 1
  • EP2980416B1 patent drawingFigure 2a
  • EP2980416B1 patent drawingFigure 2b

AI summary

Hydraulic section (1) for use in a hydraulic distributor (10) comprising: a valve body (2) with a main spool (3); a piston (11); a flow regulating element (21) receiving the hydraulic fluid coming from a front chamber (30), the piston (11) having a head (12a) of the stem (12) engaged in the flow regulating element (21); an intermediate chamber (16) delimited by the stem (12) of the piston (11); control means (6, 7, 18) operatively active on the intermediate chamber (16) to alter its pressure so that the combined piston (11) - regulating element (21) system goes from a balance condition, in which the regulating element (21) is inactive, and a decoupling condition, in which the pressure of the front chamber (30) is decoupled from the pressure of the intermediate chamber (16).