Multiple Stator Underwater Jet Motor for Marine Propulsion

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Solution Overview

Problem

Conventional electric motors for marine vessels face issues such as low efficiency at varying speeds, corrosion of stainless steel bearings, cavitation, inefficiency due to centrifugal forces scattering water, rapid warm-up, and limited design flexibility, which restricts their widespread use, especially in small marine vehicles.

Innovation Solution

The development of a brushless, synchronous, servo fan motor with multiple axial and radial stators optimized for efficiency across a wide speed range, using ironless stators, hybrid hydrodynamic and magnetic bearings, and a nozzle system to generate a high-pressure water jet, along with a control unit that adjusts stator activation and nozzle diameter for maximum efficiency and maneuverability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If conventional electric motors are used in marine vessels, then they can provide propulsion, but they suffer from low efficiency at varying speeds and rapid warm-up

Engineering Contradiction:
Improveenergy efficiencyVSAvoidwarm-up rate
Core Design Contradiction:
Use of energy by moving objectVSTemperature

Solution Approach 1:

The motor is divided into multiple independent stator units (first stator, second stator, third stator) that can be selectively activated. This segmentation allows the motor to maintain optimal efficiency across varying speeds by engaging only the necessary stators, preventing energy waste and excessive heat generation from all stators operating simultaneously.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control unit dynamically selects which stators to activate based on the required propulsion level and operating conditions. This dynamic configuration allows the motor to adapt its efficiency characteristics to varying speed requirements while minimizing unnecessary energy conversion and heat generation, thereby controlling the warm-up rate.

Inventive Principle:
Principle #15Dynamics

2Strength

If stainless steel bearings are used in underwater motors, then they provide structural support, but they suffer from corrosion and cavitation

Engineering Contradiction:
Improvestructural supportVSAvoidcorrosion resistance
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

Traditional contact-based mechanical bearings are replaced with magnetic bearings that use magnetic fields for support. This substitution eliminates physical contact between moving parts, preventing both corrosion from water exposure and cavitation from mechanical stress, while maintaining the necessary structural support function.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The motor employs composite construction with non-corrosive materials such as fiber-reinforced polymers and corrosion-resistant alloys for bearing components. These composite materials provide both the required structural strength and resistance to underwater corrosion and cavitation conditions.

Inventive Principle:
Principle #40Composite materials

3Force

If centrifugal forces are used to move water, then propulsion is generated, but water scatters leading to efficiency loss

Engineering Contradiction:
Improvepropulsion forceVSAvoidenergy efficiency
Core Design Contradiction:
ForceVSLoss of energy

Solution Approach 1:

A water guide structure acts as an intermediary between the impeller and the nozzle. This guide channels the water flow in a controlled manner, preventing scattering caused by centrifugal forces and directing the water efficiently through the nozzle to generate propulsion, thereby reducing energy loss.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The motor system changes the flow parameters of water by using a variable geometry nozzle that adjusts its opening based on operating conditions. This parameter adjustment optimizes the water jet direction and velocity, converting the centrifugal force more effectively into useful propulsion while minimizing energy loss from scattering.

Inventive Principle:
Principle #35Parameter changes

4Device complexity

If single stator motors are used, then the design is simple, but efficiency is limited at different speeds

Engineering Contradiction:
Improvemotor structureVSAvoidenergy efficiency
Core Design Contradiction:
Device complexityVSUse of energy by moving object

Solution Approach 1:

The motor is divided into multiple independent stator units (first stator, second stator, third stator) that can be selectively activated. This segmentation allows the motor to maintain optimal efficiency across varying speeds by engaging only the necessary stators, preventing energy waste and excessive heat generation from all stators operating simultaneously.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control unit dynamically selects which stators to activate based on the required propulsion level and operating conditions. This dynamic configuration allows the motor to adapt its efficiency characteristics to varying speed requirements while minimizing unnecessary energy conversion and heat generation, thereby controlling the warm-up rate.

Inventive Principle:
Principle #15Dynamics

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 achieves over 90% efficiency across a wide range of speeds, reduces maintenance needs, and allows for durable, lightweight designs suitable for various marine vessel sizes, enhancing propulsion control and reducing energy consumption.

Implementation Method 1

magnetic bearing components (1.4)

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

hydrodynamic bearing components (1.7)

Methodology Applied
Scientific EffectHydrodynamic pressure: Pressure Gradient

Implementation Method 3

at least one permanent magnet bars (1.5)

Methodology Applied
Scientific EffectMagnetism: Magnetism

Implementation Method 4

The rotor and the blades fixed in it form the impeller together. The impeller rotates with no contact to the stator on the hydrodynamic bearings supported by the magnetic bearings. The system pushes the incoming water backward through its nozzle with a high pressure forming a water-jet flow

Methodology Applied
Scientific EffectHydrodynamic flow: Fluid Spray

Data Source

PatentEP3595967B1Electrical underwater jet motor with multiple stator for sea vehicles
Publication Date: 2021.08.11 MISAL TASARIM DANISMANLIK MAKINA MEDIKAL ITHALAT IHRACAT SAN VE TIC LTD STI
  • EP3595967B1 patent drawingFigure 1~1-B
  • EP3595967B1 patent drawingFigure 2~3
  • EP3595967B1 patent drawingFigure 4~6

AI summary

In summary, the invention is an electric underwater jet engine system designed for vehicles traveling above or below the sea and which contains multiple stator units which are equipped with microprocessors containing relevant algorithms for certain speeds. Naturally, this system can be applied to all marine vehicles intended for civilian or military purposes. Compared to similar electric motors, these engines we have described have high efficiency and are much more powerful while they are small and they consume less energy. The surfaces of the rotor which are affected by the corresponding stator rotate at the hydrodynamic magnetic bearing which is designed for maximum efficiency. In high power motors, the rotor rotates in axial and radial directions, in the hybrid hydrodynamic bearing and magnetic bed, and the rotor and stator do not contact each other. It can also be used as a turbine at times when the engine is not used for propulsion, and the propeller blades rotating by waves or water flow can recharge the batteries. Especially in the case of sailboats, the battery can be recharged using the proposed invention as a turbine.