Torque Reaction Engine for Underwater Propulsion
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Solution Overview
Problem
Conventional underwater craft that mimic fish-like motion face challenges with driveshaft penetrations through the hull, leading to issues like leakage, degradation, friction, and limited depth and operating range due to complex labyrinth seals or reduced efficiency from flooding motors with oil.
Innovation Solution
The use of a torque reaction engine (TRE) secured to a fin, where the central shaft is inside a pressure vessel, eliminating the need for driveshaft penetrations and allowing for cyclic oscillation to accelerate thrust fluid, thereby propelling the craft without the drawbacks of conventional systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional driveshaft penetrations are used to transmit power to fins, then propulsion function is achieved, but leakage, friction, and limited operating depth occur
Solution Approach 1:
The patent extracts the driveshaft penetration from the system by placing the entire motor assembly inside the pressure vessel. The motor shaft connects directly to the fin without penetrating the hull, eliminating the need for complex labyrinth seals and their associated reliability issues with leakage and friction.
Solution Approach 2:
The motor assembly is nested inside the pressure vessel, with the motor shaft extending internally to connect to the fin. This nested configuration allows power transmission without external penetrations, solving the seal reliability problem while maintaining propulsion functionality.
2Reliability
If labyrinth seals are used to prevent leakage at driveshaft penetrations, then sealing is improved, but friction and limited depth range occur
Solution Approach 1:
The patent removes the labyrinth seal entirely by eliminating the driveshaft penetration. The motor assembly is positioned internally with direct shaft-to-fin connection, so no sealing mechanism is needed at the hull interface, thereby eliminating friction and depth limitations associated with seals.
3Reliability
If motors are flooded with oil to prevent leakage, then sealing is achieved, but efficiency is reduced
Solution Approach 1:
The motor is nested within the pressure vessel in a dry environment, eliminating the need for oil flooding. The sealed pressure vessel contains the motor, allowing it to operate efficiently without oil while still preventing leakage through the pressure vessel's inherent sealing 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 solution enables efficient propulsion of underwater craft without the limitations of conventional driveshaft penetrations, reducing friction, leakage, and maintenance costs while extending operational depth and range.
Implementation Method 1
A torque reaction engine (TRE) may be secured to a fin (110) of a watercraft. The TRE may comprise a central shaft (315) inside a pressure vessel (305), wherein the central shaft (315) may rotate, and wherein the fin (110) may be secured to the pressure vessel (305). An engine may be located between and/or may comprise the inertial mass and the central shaft (315), wherein the engine may cause the inertial mass to change its acceleration around, within, or relative to the central shaft (315), thereby rotating the central shaft (315) through reaction torque
Implementation Method 2
cyclic oscillation to accelerate thrust fluid, thereby propelling the craft
Data Source
AI summary
A robotic fish comprises one or more torque reaction engines and a fish body, wherein the torque reaction engine cyclically oscillates and causes a wave to propagate across the fish body, including through a flexible wing comprising a disk, accelerating thrust fluid and propelling the robotic fish.