Submarine Thrust Bearing Mounting to Prevent Shaft Misalignment

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Solution Overview

Problem

Existing submarine thrust bearings experience increased wear and reduced operational reliability due to deformation of the pressure vessel at greater diving depths, causing misalignment between the shaft and thrust bearing, which redirects propulsion forces into the hull.

Innovation Solution

A thrust bearing design that is connected directly to the end of the pressure hull via tension rods, eliminating support from the deck or bottom, maintaining alignment with the shaft axis despite deformations, and transferring forces directly into the end floor and hull.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional stern drive with propeller and drive shaft is used in a submarine, then propulsion function is achieved, but the drive shaft penetrates the pressure hull creating vulnerability to water ingress and mechanical failure

Engineering Contradiction:
Improvedrive shaft reliabilityVSAvoidwater ingress risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A magnetic coupling mechanism acts as an intermediary between the drive shaft and propeller, eliminating the need for a physical penetration through the pressure hull. The drive shaft rotates within a non-magnetic bearing housing, and magnetic fields transmit rotational force to the propeller without direct mechanical connection across the hull boundary, thus preventing water ingress while maintaining propulsion functionality.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If the drive shaft is enclosed within the pressure hull to prevent water ingress, then protection against water ingress is improved, but the mechanical coupling between drive shaft and propeller becomes complex

Engineering Contradiction:
Improvewater ingress protectionVSAvoidmechanical coupling complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent replaces the traditional mechanical coupling system (gears, belts, or direct connection) with a magnetic coupling system. Magnetic fields transmit rotational force from the enclosed drive shaft to the external propeller without physical contact, simplifying the mechanical coupling while maintaining effective power transmission and allowing the drive shaft to remain protected within the pressure hull.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Object-affected harmful factors

If a magnetic coupling system is used to eliminate drive shaft penetration, then protection against water ingress is improved, but the complexity of the magnetic coupling mechanism increases

Engineering Contradiction:
Improvewater ingress protectionVSAvoidmagnetic coupling complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The magnetic coupling system is segmented into distinct functional components: a drive shaft with magnetic coupling elements enclosed within the pressure hull, a non-magnetic bearing housing that isolates the magnetic components, and an external propeller with corresponding magnetic coupling elements. This segmentation allows each component to be optimized independently and simplifies the overall system by eliminating the need for complex sealed penetrations.

Inventive Principle:
Principle #1Segmentation

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

Reduces wear by preventing tilting of the thrust bearing relative to the shaft, maintaining alignment, and allows for a more compact and lighter construction by directing forces efficiently into the pressure hull.

Implementation Method 1

The drive shaft is rotatably supported by a non-magnetic bearing (30) having a magnetic coupling for coupling drive shaft rotation to propeller rotation

Methodology Applied
Scientific EffectMagnetic coupling: Magnetic Field

Data Source

PatentEP4380849B1Submarine with a thrust bearing for coupling the propulsion forces from the drive shaft into the pressure hull
Publication Date: 2026.05.06 TKMS GMBH
  • EP4380849B1 patent drawingFigure 1
  • EP4380849B1 patent drawingFigure 2

AI summary

The present invention relates to a submarine with a pressure hull and a drive system, wherein the drive system has a motor, a shaft and propeller, wherein the shaft is guided through the pressure hull, wherein the shaft is guided in the interior of the pressure hull by way of a thrust bearing 10, wherein the thrust bearing 10 is configured to dissipate the propulsion force generated by way of the propeller in a manner which is transmitted to the submarine, characterized in that the thrust bearing is connected to the hull bottom 30 of the pressure hull.