Vessel Fin Stabilizer Drive With Sliding Teeth for Zero Backlash
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional fin roll stabilizers for marine vessels rely on complex hydraulic systems, which are prone to leaks, overheating, and maintenance issues, and alternative direct drive electric motors suffer from backlash and efficiency problems.
Innovation Solution
An oscillating separate individual sliding tooth drive system using a logarithmic spiral is introduced, allowing for improved torque control and reduced or zero backlash, along with flexible motor and drive element placement and the use of standardized components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If traditional hydraulic systems are used to power fin roll stabilizers, then sufficient torque and power can be delivered, but the system becomes complex with multiple components (pumps, valves, cylinders, hoses) that require maintenance and are prone to leaks and overheating
Solution Approach 1:
The patent extracts and eliminates the complex hydraulic system components (pumps, valves, cylinders, hoses, reservoirs) from the stabilizer drive system, replacing them with a direct-drive electric motor and oscillating tooth mechanism. This removal of unnecessary components directly reduces system complexity while maintaining the required torque delivery capability through the electric motor.
Solution Approach 2:
The patent substitutes the hydraulic mechanical system with an electric motor-driven mechanical system. The electric motor directly drives the oscillating tooth mechanism, eliminating the need for hydraulic fluid power transmission. This substitution reduces complexity by removing hydraulic components while maintaining adequate torque through direct electric-mechanical coupling.
2Power
If hydraulic systems operate at high pressure to deliver sufficient power, then torque capacity is improved, but the risk of leaks, overheating, and component failure increases
Solution Approach 1:
The patent replaces the high-pressure hydraulic system with a direct-drive electric motor system. The electric motor inherently provides high torque at low speed without requiring high pressure, thereby eliminating the reliability issues associated with high-pressure hydraulic components such as leaks, overheating, and component failure.
Solution Approach 2:
The electric motor provides self-regulating torque control through its inherent electromagnetic characteristics, eliminating the need for complex pressure regulation and flow control mechanisms required in hydraulic systems. This self-service capability improves reliability by removing components that are prone to failure under high pressure.
3Power
If planetary gear sets are used in direct drive electric motors, then torque multiplication is achieved, but backlash and positioning errors increase due to gear wear
Solution Approach 1:
The patent extracts and eliminates the planetary gear set from the direct drive electric motor system. By removing the gear mechanism entirely, the system achieves direct coupling between the electric motor and the oscillating tooth mechanism, thereby eliminating backlash and positioning errors that would otherwise result from gear wear.
Solution Approach 2:
Instead of using gear reduction to achieve torque multiplication, the patent inverts the approach by using a high-torque electric motor that directly drives the oscillating tooth mechanism. This inversion eliminates the need for intermediate gear stages, thereby maintaining positioning accuracy while achieving the required torque output.
4Power
If complex hydraulic plumbing and interconnecting components are used, then power transmission is achieved, but installation difficulty and maintenance requirements increase
Solution Approach 1:
The patent extracts and removes the complex hydraulic plumbing infrastructure (hoses, pipes, connections, fittings) from the system. The power transmission function is achieved instead through direct mechanical coupling of the electric motor to the oscillating tooth mechanism, dramatically simplifying installation and eliminating maintenance of hydraulic connections.
5Power
If hydraulic fluid is used to transmit power, then sufficient torque can be delivered, but environmental contamination and fire hazards are introduced
Solution Approach 1:
The patent substitutes the hydraulic fluid power system with an electric motor system. This substitution eliminates the use of hydraulic fluid entirely, thereby removing the environmental contamination risks (oil leaks into bilge and ocean) and fire hazards (vaporized oil ignition) associated with hydraulic systems while maintaining adequate torque delivery through direct electric drive.
Data Source
Figure 1~2
Figure 3~8
Figure 9
AI summary
A vessel hull stabilization system includes a housing having a rotatable shaft mounted thereto, the shaft configured to connect to a fin such that the fin is located on an outside of the vessel hull and the housing is located on an inside of the vessel hull. A drive system is mounted to the housing and includes a motor and a drive element. The motor is connected to a central shaft of the drive element and an outer element of the drive element is connected to the fin shaft. The drive element includes a plurality of teeth positioned between the outer element and the central shaft such that when the motor rotates the central shaft, the plurality of teeth oscillate in a direction perpendicular to an axis of the central shaft to interact with and rotate the outer element. A controller receives sensor readings to determine control signals to send to the motor(s) to impart rotation of the fin.