Coaxial Propeller Torque Boosting Mechanism

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Solution Overview

Problem

Existing marine vessel propeller systems face inefficiencies due to insufficient shaft torque, leading to increased fuel costs and engine wear, particularly when using dual counter-rotating propeller structures which incur mechanical losses and reduced efficiency from de-energized water usage by the rear propeller.

Innovation Solution

A propeller device with a main shaft, a front propeller, and a coaxially mounted rear propeller, utilizing an adapter with pitched seating surfaces and resilient locking elements that synchronize the rotation of both propellers with the main shaft, allowing the rear propeller to contribute additional torque by rotating in the same direction as the front propeller during forward movement and independently during rearward movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a dual counter-rotating propeller structure is used, then propeller thrust increases, but mechanical losses increase due to separate power transfer means

Engineering Contradiction:

Improvepropeller thrustVSAvoidmechanical losses

Core Design Contradiction:

ForceVSLoss of energy

Solution Approach 1:

The patent merges the power transfer functions of both propellers into a single shared power transfer means (gear mechanism). The front and rear propellers are connected through a common intermediate gear, allowing torque from the engine shaft to be distributed to both propellers through this single transmission system, thereby eliminating the need for separate power transfer means and reducing mechanical losses.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent implements a nested gear configuration where the intermediate gear is positioned between the engine shaft and the propeller shafts. The first power transfer means connects the engine shaft to the intermediate gear, and the second power transfer means connects the intermediate gear to the propeller shafts, creating a nested transmission structure that efficiently transfers power to both propellers through a unified system.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Force

If a dual counter-rotating propeller structure is used, then propeller thrust increases, but the rear propeller uses de-energized water causing efficiency loss

Engineering Contradiction:

Improvepropeller thrustVSAvoidefficiency

Core Design Contradiction:

ForceVSProductivity

Solution Approach 1:

Instead of using counter-rotating propellers where the rear propeller rotates opposite to the front propeller, the patent employs co-rotating propellers that rotate in the same direction. This inversion of the rotation direction allows the rear propeller to interact with the water flow from the front propeller in a beneficial manner, extracting energy from the swirling water rather than using already de-energized water, thereby improving overall system efficiency.

Inventive Principle:

Principle #13The other way round (Inversion)

3Power

If shaft torque is insufficient, then engine power output is limited, but fuel costs increase and engine wear increases

Engineering Contradiction:

Improveengine power outputVSAvoidfuel costs and engine wear

Core Design Contradiction:

PowerVSLoss of energy

Solution Approach 1:

The patent incorporates a torque amplification mechanism that pre-adjusts the torque distribution to the propellers before the engine operates at full power. The gear system is designed with specific gear ratios that amplify the torque from the engine shaft, ensuring that sufficient torque reaches the propellers even at lower engine revolutions. This preliminary torque adjustment allows the engine to operate more efficiently in the optimal power band, reducing fuel consumption and wear while maintaining adequate thrust.

Inventive Principle:

Principle #10Preliminary action

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

Enhances shaft torque efficiency by ensuring coordinated propeller rotation, reducing mechanical losses and increasing thrust, while being adaptable to conventional propellers, thus improving vessel movement capacity without additional engine power.

Implementation Method 1

a plurality of locking elements resiliently movable in the axial direction, each being in contact with the seating surfaces of the adaptor from one end and communicated with the rear propeller from the other end

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentEP3461735B1Unidirectional torque boosting propeller

Publication Date: 2019.09.25 UELGEN MEHMET NEVRES

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AI summary

A propeller device comprising a main shaft communicated from one end to a marine vessel engine transmission; a front propeller (1) provided on the main shaft, the front propeller having a hub (2) and a plurality of blades (3) extending radially outwardly from the hub; a rear propeller (34) being co-axially to and spaced apart from the front propeller backwardly in an axial direction, the rear propeller having a hub (4) and a plurality of blades (5) extending radially outwardly from the hub. The device further comprises an adaptor (7) being coaxial with the main shaft and comprising a second shaft (6) for supporting the rear propeller and a plurality of pitched-formed seating surfaces (32) having ramps, the seating surfaces being spaced apart from the second shaft in axial direction, and the adaptor communicated with the rear side of the front propeller in the axial direction; a plurality of locking elements (18) resiliently movable in the axial direction, each being in contact with the seating surfaces of the said adaptor from one end and communicated with the rear propeller from the other end.