Propulsion Unit Mounting Structure for Tilted Hull Sealing

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Solution Overview

Problem

The challenge lies in efficiently mounting propulsion units to floating structures, particularly in scenarios where docking is impractical, such as with semisubmersible rigs, and existing solutions face issues with tilted mounting surfaces that risk damaging seals and require multiple propulsion unit variants.

Innovation Solution

A mounting structure with guiding protrusions and cylindrical cavities that tilt about a pivot point to align mounting surfaces, allowing for underwater installation without damaging seals and reducing the need for multiple propulsion unit variants, while maintaining hydrodynamic efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a tilted mounting surface is provided on the hull for mounting propulsion members, then the propulsion members can be mounted in a tilted position, but there is a high risk of damaging the sealing during mounting when heavy metal objects move towards each other at an angle

Engineering Contradiction:
Improvemounting position flexibilityVSAvoidsealing integrity
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The mounting surface is pre-heated before the propulsion member is brought into contact with it. This preliminary heating ensures that the sealing material becomes more compliant and can accommodate the mounting process without being damaged, even when mounting at tilted positions. The heating is performed in advance to prepare the sealing interface before the critical contact moment.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If mounting surfaces are provided in a horizontal position with propulsion members tilted within the propulsion unit, then sealing damage is avoided, but the number of different kinds of propulsion units to be manufactured increases

Engineering Contradiction:
Improvesealing integrityVSAvoidpropulsion unit variants
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The propulsion unit is designed with a universal horizontal mounting interface that can accommodate tilted propulsion members through the heating method. This allows a single standardized propulsion unit design to be mounted at various angles by controlling the thermal state of the mounting surface, eliminating the need for multiple specialized propulsion unit variants for different mounting orientations.

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

3Reliability

If mounting surfaces are provided in a horizontal position, then sealing damage is avoided, but mounting such propulsion units to the hull becomes very difficult

Engineering Contradiction:
Improvesealing integrityVSAvoidmounting difficulty
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The mounting surface is pre-heated to create thermal expansion and increased material compliance before the propulsion member is positioned and pressed against it. This preliminary thermal preparation significantly reduces the force required for mounting and makes the operation much easier, while still maintaining sealing integrity through controlled thermal management.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The thermal parameter of the mounting surface is dynamically changed during the mounting process. By controlling the temperature of the mounting surface, the material properties of the sealing interface are modified to facilitate easier mounting while preserving seal integrity. The temperature is adjusted to optimize both the ease of mounting and the sealing performance.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4253223A1Mounting structure, mounting arrangement, propulsion unit, floating structure and method for mounting propulsion unit to floating structure
Publication Date: 2023.10.04 ABB (SCHWEIZ) AG
  • EP4253223A1 patent drawingFigure 1~3
  • EP4253223A1 patent drawingFigure 4~6
  • EP4253223A1 patent drawingFigure 7~9

AI summary

A mounting structure (1) for mounting a propulsion unit (2) to a hull (4) of a floating structure (3) comprises a first mounting surface (5) and a sealed portion (6) provided on the first mounting surface for sealing the propulsion unit (2) to the hull (4). The first mounting surface (5) is further provided with a pivot point (10) provided at an edge (8) or in the vicinity of an edge (8) of the first mounting surface and outside the sealed portion (6), and at least two first protrusions (11) spaced from each other on the first mounting surface (5). Each of the first protrusions (11) comprises a surface (15) at least on a side of the first protrusion (11) facing away from the pivot point (10), which surface (15) is formed at least in a direction (17) perpendicular to the first mounting surface in a manner dependent of a distance (16) between the pivot point (10) and the surface (15) in such a manner that the first protrusion (11) provided in a cylindrical cavity formed in a counterpart is configured to guide a mutual tilting movement of the cylindrical cavity and the first protrusion (11), when the mounting structure (1) and, thus, the first protrusions (11) are tilted with respect to the cylindrical cavities about the pivot point (10).