Stern-Mounted Propulsion Mounting Assembly with Forward Convergence

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Solution Overview

Problem

Conventional marine vessel propulsion systems face limitations in achieving optimal steering angles and propulsion force alignment, particularly when maneuvering, as they often require large steering angle changes and cannot efficiently combine forward and transverse movements without shifting gears or using additional propulsion devices.

Innovation Solution

The mounting assembly for stern-mounted propulsion units includes angle-setting members that forwardly angle the propulsion units inwardly and forwardly, allowing their lines of action to intersect between the center of rotation and the stern, enabling a biased steering range that allows for counter-clockwise and clockwise rotational adjustments while moving sideways, and facilitating pure sideways movement by aligning propulsion forces with the vessel's centerline.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If conventional stern-mounted propulsion units are used with parallel alignment to the vessel centerline, then the steering mechanism is simple, but the vessel cannot achieve efficient sideways movement or rotational adjustments without large steering angle changes

Engineering Contradiction:
ImprovemaneuverabilityVSAvoidmounting assembly complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The propulsion units are pre-positioned at angled orientations relative to the vessel centerline through the mounting assembly, so that when the units are in the neutral position, their thrust vectors are already oriented to provide sideways movement capability. This preliminary angular positioning eliminates the need for large steering angle changes during operation, enabling efficient lateral translation and rotational adjustments.

Inventive Principle:
Principle #10Preliminary action

2Adaptability or versatility

If the propulsion units are angled forwardly towards the bow, then sideways movement and rotational adjustments are enabled, but the steering range distribution becomes asymmetric

Engineering Contradiction:
Improvemovement capabilityVSAvoidsteering range balance
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The mounting assembly creates an asymmetric steering range distribution by angling the propulsion units forwardly towards the bow. This asymmetric configuration is intentional and enables the vessel to achieve sideways movement and rotational adjustments that would be impossible with symmetric parallel alignment. The asymmetric angle distribution is optimized to provide the necessary maneuverability for the vessel's operational requirements.

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP2996935B1Mounting assembly for positioning stern-mounted propulsion units with a forward convergence
Publication Date: 2020.06.17 MARINE CANADA ACQUISTION INC
  • EP2996935B1 patent drawingFigure 1
  • EP2996935B1 patent drawingFigure 2
  • EP2996935B1 patent drawingFigure 3

AI summary

There is provided a mounting assembly for a marine vessel having a pair of stern- mounted propulsion units. The assembly includes a pair of angle-setting members which forwardly angle the propulsion units towards a bow of the marine vessel when each propulsion unit is at the center of its total steering range. Each propulsion unit has a line of action of its propulsion force. The lines of action of the propulsion units intersect each other between a center of rotation of the marine vessel and a stern of the marine vessel when the propulsion units are steered forwardly towards each other.