Pressure-Neutral Electric Motor Using Deformable Pressure Bag

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Solution Overview

Problem

Existing deep-sea electric motors face challenges in withstanding high hydrostatic pressure, requiring either pressure-stable containers or pressure-neutral systems, where components are exposed to pressure evenly, and existing solutions often involve complex and costly pressure-resistant housings and pressure equalization mechanisms.

Innovation Solution

A pressure-neutral electric motor design using a reversibly deformable closed pressure bag with an open supply hose for pressure equalization, surrounded by pressurized liquid, filled with hydrofluoroether as the pressure fluid, allowing for compact, lightweight, and cost-effective construction without large, heavy pressure-resistant housings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If pressure-stable containers are used for electric motors in deep sea, then the motors can withstand high hydrostatic pressure, but the weight and complexity of the system increase significantly

Engineering Contradiction:
Improvepressure resistanceVSAvoidmotor weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

A pressure equalization element (flexible membrane or bellows) is introduced as an intermediary between the motor unit and the surrounding pressure fluid. This element allows gradual pressure equalization, preventing sudden pressure shocks while protecting the motor from extreme pressure differences, thus reducing the need for heavy pressure-stable containers

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system changes the pressure parameter dynamically by allowing the internal pressure to equalize with external hydrostatic pressure through the deformable pressure equalization element. This eliminates the need for rigid pressure-stable containers that would otherwise be required to maintain constant internal pressure

Inventive Principle:
Principle #35Parameter changes

2Reliability

If pressure-stable containers are used for electric motors in deep sea, then the motors can withstand high hydrostatic pressure, but the device complexity and cost increase

Engineering Contradiction:
Improvepressure resistanceVSAvoidhousing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The pressure equalization element is designed as a flexible membrane or bellows that can deform under pressure. This flexible structure replaces complex rigid pressure-stable containers, simplifying the overall housing design while maintaining pressure resistance capability

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The pressure equalization element is designed to be reversibly deformable, allowing the system to dynamically adapt to changing external pressure conditions. This dynamic approach replaces static, complex pressure-stable containers with a simpler, adaptive structure

Inventive Principle:
Principle #15Dynamics

3Reliability

If air bubbles remain in the pressure fluid during filling, then the pressure equalization is compromised, but complete filling becomes difficult to achieve

Engineering Contradiction:
Improvepressure equalization effectivenessVSAvoidfilling process difficulty
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The filling process is performed in a vacuum environment before deployment. This preliminary action removes air bubbles from the pressure fluid during filling, ensuring complete wetting of the pressure equalization element and eliminating voids that would compromise pressure equalization effectiveness

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

A vacuum environment is used during the filling process to prevent air bubbles from forming in the pressure fluid. This controlled inert environment ensures complete filling and proper wetting of all components, particularly the pressure equalization element

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

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 design achieves significant weight reduction and improved manageability, enabling the motor to operate effectively at deep-sea depths with efficient pressure and temperature compensation, while avoiding the need for complex pressure equalization mechanisms and expensive materials.

Implementation Method 1

a dielectric pressure fluid 07, the filling under atmospheric pressure alternating with venting in a vacuum, in order to guarantee that the filling is free of air bubbles at the end of the filling

Methodology Applied
Scientific EffectHydrostatic pressure transmission: Pascal's Law

Implementation Method 2

a dielectric pressure fluid 07

Methodology Applied
Scientific EffectDielectric property: Dielectric

Implementation Method 3

a reversibly deformable pressure equalization element 04 for pressure equalization between the pressure fluid and the hydrostatic pressure acting on the motor unit in use are arranged

Methodology Applied
Scientific EffectPressure equalization: Pascal's Law

Implementation Method 4

a reversibly deformable pressure equalization element 04

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 5

the pressure bag being filled with air during inflation and inflated to its normal volumetric condition, the housing being transparent, and the pressurized liquid used being a commercially available hydrofluoroether

Methodology Applied
Scientific EffectHydrostatic pressure: Pascal's Law

Data Source

PatentEP3673565B1Pressure independent electric motor to be applied in deep sea
Publication Date: 2021.07.14 ALFRED WEGENER INST HELMHOLTZ ZENT FUR POLAR & MEERESFORSCHUNG
  • EP3673565B1 patent drawingFigure 1
  • EP3673565B1 patent drawingFigure 2

AI summary

The invention relates to a pressure-neutral electric motor (Ol), characterized in that the pressure compensation element (04) is designed as a closed pressure bag (09) having an open supply hose (10), which leads out of the housing (02) in a pressure-tight manner, and lies around the motor unit (03), forming a gap, such that the pressure bag (09) is completely enclosed by pressurized fluid (07). The reversibly deformable pressure bag (09) fits very well to the preferably cylindrical housing (02) and the motor unit (03). It is particularly space-saving, and therefore the electric motor (01) can be designed to be particularly compact and light. The claimed pressure-neutral electric motor (01) is additionally cost-effective, because it is designed using commercially available components, particularly a simple tubular bag (18) as a pressure bag (09).