Rotating Duct Vessel Propulsion for Lateral Maneuvering
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Solution Overview
Problem
Vessel propulsion systems with electric propulsion units face inefficiencies in propulsive force generation when moving laterally or braking, due to differences in forward and backward traveling propulsive forces, limiting maximum propulsive force utilization.
Innovation Solution
A vessel propulsion apparatus with a duct and propeller assembly, including a stator and rotor, where the propeller generates forward and backward traveling forces, and a turning mechanism that adjusts the propulsive force direction by ±180 degrees, with a limited turning angle range that can be expanded for maximum force application during specific conditions like braking or lateral movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the propeller is designed to maximize forward-traveling propulsive force, then energy efficiency is improved, but the difference between forward and backward propulsive forces increases
Solution Approach 1:
The duct is made rotatable to dynamically change its orientation angle according to different operational requirements. The orientation angle adjusting mechanism allows the duct to be positioned at different angles, enabling the system to adapt to varying propulsive force needs in different directions, thereby resolving the contradiction between maximizing forward propulsive force and maintaining balanced bidirectional performance.
2Ease of operation
If the rotation speed of the propeller is limited to generate equivalent forward and backward propulsive forces, then lateral movement becomes possible, but the propulsive force generated is not maximum
Solution Approach 1:
Instead of limiting rotation speed, the invention dynamically adjusts the duct's orientation angle to control the direction of the propulsive force. This allows the propeller to operate at maximum rotation speed while the duct orientation ensures that the force is applied in the desired direction, enabling both lateral movement and maximum propulsive force utilization.
Solution Approach 2:
The invention introduces a new dimension of control by rotating the duct around the propeller shaft axis. This additional degree of freedom allows independent control of force direction separate from rotation speed, enabling lateral movement capability without compromising the magnitude of the propulsive force.
3Force
If the propeller generates maximum backward propulsive force for braking, then braking performance is improved, but the propeller must rotate in reverse direction reducing efficiency
Solution Approach 1:
The invention inverts the conventional approach by keeping the propeller rotating in the forward direction and instead rotating the duct to change the force direction. This allows the propeller to operate in its efficient forward rotation mode while the duct orientation provides the backward-directed propulsive force needed for braking, eliminating the need for reverse rotation.
4Stability of the object's composition
If the duct turning angle range is limited to a reduced range, then system stability is improved, but the ability to maximize propulsive force during lateral movement and braking is reduced
Solution Approach 1:
The system employs dynamic control of the duct orientation angle, allowing it to be adjusted within a wide range when needed for lateral movement or braking operations. The orientation angle adjusting mechanism provides stable operation during normal conditions while enabling extended angular ranges when maximum propulsive force in specific directions is required, resolving the contradiction between stability and force maximization.
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 solution allows for optimized propulsive force generation and improved vessel performance by maximizing the use of electric propulsion unit forces during lateral movement and braking, reducing the braking distance and enhancing overall traveling efficiency.
Implementation Method 1
a motor controller that rotationally drives an electric motor including the stator and the propeller in a forward rotation direction to cause the propeller to generate a forward-traveling propulsive force and in a reverse rotation direction to cause the propeller to generate a backward-traveling propulsive force
Data Source
AI summary
A vessel propulsion apparatus includes a propulsive force generator including a duct and a propeller. The duct includes a stator. The propeller includes a rim that includes a rotor disposed at a position facing the stator, and a blade on an inner side in a radial direction of the rim. The vessel propulsion apparatus further includes a steering shaft that turnably supports the duct, a motor controller that rotationally drives an electric motor including the stator and the propeller in forward and reverse rotation directions, a turning mechanism that turns the duct in a full turning angle range including a range of ±180 degrees, and a turning angle range limiter that limits a turning angle range of the turning mechanism to a reduced turning angle range narrower than the full turning angle range, and when a predetermined limitation cancellation condition is met, cancels the limitation and allows turning in a turning angle range wider than the reduced turning angle range.