Crane Hydraulic System Pressure Reducer Volume Flow Conversion

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Solution Overview

Problem

Existing hydraulic systems for cranes require separate feed pumps to generate high volume flows, which is inefficient and unnecessary when a constant pressure network is already installed, and they struggle to optimize energy balance during deep-sea hoisting operations.

Innovation Solution

A hydraulic system that couples the hydraulic circuit with a constant pressure network via a pressure reducer, allowing conversion of low volume flow with high pressure into high volume flow with low pressure, eliminating the need for a feed pump and incorporating a pressure accumulator for energy recovery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If a feed pump is used to generate high volume flow for the hydraulic consumer, then the required volume flow can be supplied, but the energy balance is worsened and additional pump equipment is required

Engineering Contradiction:
Improvevolume flowVSAvoidenergy balance
Core Design Contradiction:
Quantity of substanceVSUse of energy by moving object

Solution Approach 1:

The patent extracts the high volume flow requirement from the constant pressure network by using a pressure reducer to convert high pressure/low volume flow into low pressure/high volume flow. This eliminates the need for a separate feed pump, taking out the unnecessary pumping function while maintaining the required volume flow supply to the hydraulic consumer.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The pressure reducer acts as an intermediary device between the constant pressure network and the hydraulic circuit. It mediates the transformation of hydraulic parameters, converting high pressure/low volume flow from the constant pressure network into low pressure/high volume flow suitable for the hydraulic consumer, thereby avoiding direct connection and the need for additional pumps.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Quantity of substance

If a feed pump is installed to supply high volume flow, then the hydraulic consumer can be operated, but the system complexity increases due to additional pump equipment

Engineering Contradiction:
Improvevolume flowVSAvoidsystem complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent removes the need for a separate feed pump by extracting the volume flow conversion function from the pumping system. The pressure reducer performs the volume flow conversion directly, eliminating unnecessary pump equipment and reducing system complexity while still supplying the required high volume flow to the hydraulic consumer.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The pressure reducer serves multiple functions: it acts as a pressure reducing valve, a volume flow converter, and an energy recovery device (when combined with the accumulator). This multi-functionality replaces what would otherwise require separate components including a feed pump, thereby reducing overall system complexity.

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

3Device complexity

If the hydraulic circuit is connected to the constant pressure network directly, then the system is simpler, but the pressure and volume flow requirements of the hydraulic consumer cannot be met

Engineering Contradiction:
Improvesystem simplicityVSAvoidvolume flow
Core Design Contradiction:
Device complexityVSQuantity of substance

Solution Approach 1:

The pressure reducer serves as an intermediary component that enables connection between the constant pressure network and the hydraulic circuit while transforming the hydraulic parameters. It allows the simple direct connection architecture to be maintained while meeting the volume flow requirements through pressure-to-volume conversion, avoiding the need for complex pump systems.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Use of energy by moving object

If a pressure accumulator is added for energy recovery, then energy balance is improved, but device complexity increases

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

Solution Approach 1:

The pressure accumulator is integrated with the existing pressure reducer to create a combined energy recovery system. The accumulator stores excess pressure energy during low-demand periods and releases it during high-demand periods, enabling energy recovery without requiring separate complex energy storage systems. This multi-functional integration improves energy balance while minimizing additional complexity.

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

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 configuration reduces tank circulation rate, enhances energy recovery, and efficiently supplies high volume flows to hydraulic consumers, particularly in Active Heave Compensation modes, optimizing energy balance and reducing the need for additional pumps.

Implementation Method 1

via the pressure reducer the pressure and/or volume flow present at the respective connecting points is variable. Via the pressure reducer a low volume flow with high pressure within the constant pressure network can be convertible into a high volume flow with low pressure within the hydraulic circuit.

Methodology Applied
Scientific EffectPressure reduction and volume flow conversion: Pressure Gradient

Implementation Method 2

at least one pressure accumulator can be arranged in the hydraulic circuit. When the accumulator releases the stored pressure energy, the volume flow in the hydraulic circuit is reversed, so that this pressure energy can be released back to the constant pressure network via the pressure reducer.

Methodology Applied
Scientific EffectPressure energy storage: Hydraulic Accumulator

Data Source

PatentUS9248997B2Hydraulic system and crane
Publication Date: 2016.02.02 LIEBHERR WERK NENZING

AI summary

The present disclosure relates to a hydraulic system for a crane with at least one hydraulic circuit, which comprises at least one hydraulic consumer, and a constant pressure network, wherein the at least one hydraulic circuit is coupled with the constant pressure network via at least one pressure reducer, whereby a higher volume flow with low pressure as compared to the constant pressure network can be generated in the hydraulic circuit.