Hybrid Watercraft Propulsor With Variable Pitch And Rotating Duct

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Solution Overview

Problem

Existing watercraft propulsion systems face challenges such as limited adjustable pitch options, increased cavitation, and reduced efficiency across all speed ranges due to design tradeoffs between propeller and water jet systems.

Innovation Solution

A hybrid propulsion system combining a self-adjusting variable pitch propeller with a water jet, an exhaust-driven turbine, and a rotating duct fixed to the propeller blades, which automatically adjusts pitch based on load conditions and reduces cavitation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a fixed pitch propeller is used, then the structure is simple and reliable, but the performance cannot be optimized for different speed ranges and load conditions

Engineering Contradiction:

Improveperformance optimization for different speed rangesVSAvoidpropeller structure complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies the dynamics principle by making the propeller blades flexible rather than rigid. The blades are designed with varying flexibility along their span, allowing them to dynamically adjust their pitch angle in response to changing operational conditions such as speed and load, thereby optimizing performance across different regimes without requiring complex mechanical adjustment mechanisms

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the physical parameter of blade flexibility by using composite materials with varying stiffness properties. The blades are constructed with different material compositions and structural configurations at different sections, enabling automatic parameter adjustment of pitch angle based on operational conditions while maintaining structural integrity

Inventive Principle:

Principle #35Parameter changes

2Speed

If a water jet system is used, then top speed performance is improved, but low speed acceleration and heavy load capability are reduced

Engineering Contradiction:

Improvetop speedVSAvoidlow speed acceleration and heavy load capability

Core Design Contradiction:

SpeedVSProductivity

Solution Approach 1:

The patent applies universality by designing a single propeller system that can effectively perform multiple functions across different speed ranges and load conditions. The flexible blades automatically adapt their pitch to provide optimal performance whether the watercraft is accelerating from rest, cruising at moderate speeds, or operating at high speeds, eliminating the need for separate propulsion systems for different operational regimes

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Ease of manufacture

If traditional propeller design is used, then manufacturing is simple, but cavitation and turbulence cause propeller slip and drag reducing efficiency

Engineering Contradiction:

Improvepropeller manufacturing simplicityVSAvoidcavitation and turbulence

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by implementing different structural characteristics at different locations on the propeller blades. The blades feature varying flexibility, thickness, and material composition at different radial positions, with the tips being more flexible than the root sections. This localized differentiation allows the blade tips to better handle cavitation and turbulence while maintaining overall structural integrity and manufacturability

Inventive Principle:

Principle #3Local quality

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

The hybrid propulsion system enhances low-speed acceleration, increases top speed, reduces cavitation, and improves overall efficiency across all speed ranges, leading to improved fuel efficiency and performance.

Implementation Method 1

an exhaust driven turbine

Methodology Applied

Scientific EffectTurbine: Turbine

Implementation Method 2

The blade rotation creates dynamics similar to a rotating screw or airfoil, a pressure difference between forward and rear surfaces of the blades is produced and accelerates the water behind the blade to create propulsive force

Methodology Applied

Scientific EffectPressure difference: Pressure Gradient

Implementation Method 3

Another weakness of current propeller design is cavitation, turbulence and ventilation which causes propeller slip and drag

Methodology Applied

Scientific EffectCavitation: Cavitation

Data Source

PatentUS12286203B2Hybrid propulsor for watercraft

Publication Date: 2025.04.29 JARDINIANO MARANGAL MENDOZA

AI summary

A novel watercraft propulsion device is disclosed that includes multiple propulsive elements improving power and efficiency over prior designs. A self-adjusting variable pitch propeller is combined with a water jet and an exhaust driven turbine to provide optimal thrust and efficiency across the range of engine power, load and watercraft speed. Propulsive elements are axially disposed around a central drive shaft and exhaust port with the combined water jet/exhaust turbine disposed closest to drive shaft and the variable pitch propeller attached to the exterior of the water jet housing. A rotating duct is fixed to the propeller blades and rotates with the blades to reduce cavitation. Combined apparatus provides increased performance and efficiency over all watercraft speeds/load as well as additional safety due to the ducted propeller. Propulsor with an inducer, conical impeller and a diffuser also shown.