Swivel Traction Propeller Drives for Watercraft Maneuverability
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Solution Overview
Problem
Conventional watercraft propulsion systems, particularly inboard systems, face limitations in maneuverability and efficiency due to fixed propeller shafts and tunnel designs, which restrict steering capabilities and increase drag, especially in tight spaces and low-speed conditions.
Innovation Solution
The implementation of steerable drives with multiple swivel traction propellers positioned within tunnels or on the hull bottom, allowing for horizontal thrust generation and directional control through propeller swiveling, along with adjustable trim angles to optimize thrust and reduce drag.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a fixed propeller shaft is used in conventional inboard systems, then the structure is simple and reliable, but maneuverability is limited and steering capabilities are restricted
Solution Approach 1:
The patent applies the dynamics principle by making the propeller shaft swivable rather than fixed. The drive shaft is connected to the propeller through a universal joint that allows the shaft to rotate relative to the propeller, enabling the propeller to be positioned at various angles for steering while the shaft remains protected within the hull. This dynamic configuration provides steering capability without requiring a separate rudder mechanism.
Solution Approach 2:
The swivable drive shaft system provides multiple functions: it serves as both the propulsion transmission shaft and the steering mechanism. By integrating the steering function into the drive shaft assembly, the system eliminates the need for separate steering components, thereby reducing overall system complexity while improving maneuverability.
2Speed
If a tunnel design is used to minimize hull draft, then the watercraft can operate in shallow waters, but drag increases especially at low speeds
Solution Approach 1:
The patent reduces drag by making the propeller swivable, allowing it to be positioned at optimal angles for different operating conditions. At high speeds, the propeller can be aligned with the direction of motion to minimize resistance, while at low speeds it can be angled to provide thrust without excessive drag. This dynamic positioning enables the system to achieve high top speed while minimizing energy loss across various speed ranges.
Solution Approach 2:
The system changes the operational parameters of the propeller by allowing variable angle adjustment through the swivel mechanism. This enables optimization of the propeller's angle of attack and orientation relative to the hull and water flow, thereby reducing drag at low speeds while maintaining high-speed performance. The tunnel design combined with variable propeller positioning allows the watercraft to operate efficiently across a wide speed range.
3Ease of operation
If a single fixed propeller drive is used, then the device complexity is low, but maneuverability in tight spaces is insufficient
Solution Approach 1:
The patent enables maneuverability in tight spaces by making the propeller swivable, allowing the watercraft to turn and reposition the propeller angle rapidly. This dynamic positioning capability provides the agility needed for tight space maneuvers while using a single drive unit, avoiding the need for multiple independent drive systems.
Solution Approach 2:
The drive system is segmented into functional components: the drive shaft, the universal joint, and the propeller assembly. This segmentation allows each component to perform its specific function independently while working together as an integrated system, providing maneuverability through the propeller's swiveling capability without requiring multiple separate drive units.
4Use of energy by moving object
If the propeller is positioned to work in undisturbed water for efficiency, then propulsion efficiency increases, but steering capability is reduced
Solution Approach 1:
The patent resolves this contradiction by making the propeller swivable, allowing it to be positioned at various angles relative to the drive shaft. When the propeller is aligned with the drive shaft, it operates in undisturbed water for maximum efficiency. When steering is required, the propeller can be angled to provide lateral thrust while still maintaining reasonable efficiency, thus balancing both propulsion efficiency and steering capability.
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 configuration enhances maneuverability, particularly in tight spaces and low-speed conditions, by providing tighter turns and improved lateral movement without turning, while reducing drag and increasing top speed with a more compact engine room, thus improving overall watercraft performance.
Implementation Method 1
The propeller generates thrust, generally horizontally, to move the watercraft
Implementation Method 2
Swiveling the propeller unit directs the thrust to provide steering and other performance advantages
Implementation Method 3
Inboard propulsion systems for planing watercraft sometimes employ a cutout tunnel in the hull to keep hull draft to a minimum
Data Source
AI summary
Enhanced watercraft performance is provided by combinations of one or more inboard swivel propulsion drives and hull tunnels. A tunnel at the hull centerline with specific features provides performance advantages for a center swivel propulsion drive. Use of front propeller based traction propulsion is particularly advantageous in the swivel drive systems and allows the use of tunnels with improved tunnel conformations. Advantages of the traction swivel drive arrangements include minimization of hull space with smaller engine room volume, greater propulsion efficiency and improved watercraft handling.