Bellows Pressure Compensation for Deep-Sea Hydraulic Isolation

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Solution Overview

Problem

Existing deep-sea drilling equipment faces challenges in generating and maintaining hydraulic working pressure due to the corrosive and contaminative nature of seawater, leading to operational inefficiencies and increased maintenance costs.

Innovation Solution

A device utilizing a bellows compensator device with multiple resilient bellows elements, which are partially formed from corrosion-resistant materials, to adjust medium pressure relative to ambient seawater pressure, protecting internal components from seawater exposure and allowing for robust and cost-effective operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If seawater is used to operate the cylinder assembly, then the device can generate hydraulic operating pressure at the installation site, but corrosion and contamination from sediment particles and microorganisms occur

Engineering Contradiction:
Improvehydraulic operating pressure generationVSAvoidcorrosion and contamination
Core Design Contradiction:
PowerVSObject-affected harmful factors

Solution Approach 1:

The device is divided into separate chambers: a seawater chamber for receiving ambient pressure and a protected chamber containing the piston and hydraulic fluid. The piston assembly acts as a barrier that transmits pressure without allowing seawater contact with sensitive components, thus segmenting the corrosive environment from the mechanical system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The piston assembly serves as an intermediary element that transfers the ambient seawater pressure to the hydraulic fluid without allowing direct contact between seawater and the hydraulic system. This mediator protects against corrosion and contamination while maintaining pressure transmission functionality.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If the cylinder assembly is lined with corrosion-resistant materials, then corrosion is reduced, but the coefficient of friction increases due to deposits

Engineering Contradiction:
Improvecorrosion resistanceVSAvoidfriction during piston movement
Core Design Contradiction:
Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The design extracts the piston and hydraulic fluid from direct contact with seawater by using a sealed chamber arrangement. The piston moves within a protected environment isolated from seawater, eliminating the need for corrosion-resistant linings and avoiding the friction problems associated with saltwater deposits on moving surfaces.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If expensive corrosion-resistant materials are used for the cylinder assembly, then reliability improves, but manufacturing cost increases

Engineering Contradiction:
Improveoperational reliability in seawater environmentVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

Instead of making the entire cylinder assembly from expensive corrosion-resistant materials, the design applies protection only where necessary: the piston chamber is sealed to exclude seawater, allowing standard materials to be used for the main cylinder body while maintaining reliability in the critical protected zones.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The design uses a bladder accumulator as a replaceable, cost-effective component that can be easily replaced if needed, rather than investing in expensive, complex corrosion-resistant cylinder linings. This approach prioritizes economical, easily replaceable components over costly permanent solutions.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 device effectively compensates for seawater pressure to generate high hydraulic working pressure, ensuring reliable operation while protecting internal components from corrosion and contamination, and allowing for use at varying depths with reduced maintenance needs.

Implementation Method 1

a compensator device (35) which, when the device (1) is in use, allows a reversible change in length or expansion under the action of the seawater pressure

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

A piston is subjected to the ambient pressure of the deep sea in a cylinder, and the resulting piston movement transfers the pressure to the hydraulic fluid

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Data Source

PatentEP3017140B1Device for adjusting a media pressure relative to an ambient pressure
Publication Date: 2022.03.30 HYDAC TECH GMBH
  • EP3017140B1 patent drawingFigure 1
  • EP3017140B1 patent drawingFigure 2

AI summary

A device (1) for adjusting a media pressure relative to an ambient pressure which is defined by a depth-dependent sea water pressure during use of the device (1), wherein the sea water pressure acts on a compensator device (35) which permits a reversible change in length or elongation, characterized in that at least two compensator elements (41) of the compensator device (35) are provided in series in the direction of the change in length or elongation.