Steerable Marine Drive Trim Tab for Vessel Attitude Control
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Solution Overview
Problem
Existing marine vessel and drive combinations face limitations in optimizing hydrodynamic operation, particularly in adjusting vessel attitude and thrust vectors, which affects maneuverability and efficiency.
Innovation Solution
A marine vessel and drive combination featuring steerable marine propulsion devices with counter-rotating propellers, pivotally mounted trim tabs, and a keel-protected propulsion system that allows for asymmetric steering ranges and independent control of propulsion devices for enhanced hydrodynamic performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the trim tab is fixedly positioned on the marine drive, then the structure is simple, but the ability to adjust vessel attitude and thrust vectors is limited
Solution Approach 1:
The trim tab is made movable relative to the marine drive, allowing it to be adjusted between different angular positions. This dynamic adjustment capability enables the trim tab to optimize vessel attitude and thrust vectoring for different operating conditions, resolving the contradiction between adaptability and structural simplicity.
2Adaptability or versatility
If the complete marine drive is pivoted for trimming, then the trim function is achieved, but the complexity and size of the system increases
Solution Approach 1:
The trim function is separated from the complete marine drive by making only the trim tab movable. This segmentation allows the trim function to be achieved independently without requiring pivoting of the entire marine drive assembly, thereby reducing system complexity and size while maintaining the desired adaptability.
3Reliability
If the propeller shaft is positioned low for keel protection, then the propulsion system is protected from underwater objects, but the risk of striking objects increases
Solution Approach 1:
The marine drive is designed with a low propeller shaft position that preemptively benefits from keel protection. The keel structure is positioned to shield the propeller shaft before any potential impact can occur, creating a protective barrier in advance. This preliminary protective arrangement reduces the risk of striking underwater objects while maintaining reliability.
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 solution enhances hydrodynamic operation by enabling precise control over vessel attitude and thrust vectors, improving maneuverability, and protecting the propulsion system from underwater objects, thus enhancing the overall efficiency and safety of the marine vessel.
Implementation Method 1
at least one water-engaging propulsor such as port propeller 62... starboard propeller 72
Implementation Method 2
port trim tab 130 pivotally mounted thereto for contact by the water for adjusting vessel attitude
Data Source
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AI summary
A marine drive (54,64) and a marine vessel (22) and drive combination have a trim tab (130,132) with a forward end pivotally mounted to a marine propulsion device.