Dual Propeller Turbine Layout for Axial Force Compensation

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Solution Overview

Problem

The existing propeller turbines face significant axial force challenges that necessitate the use of axial bearings, which are difficult to lubricate and experience increased losses at high revolutions, leading to decreased efficiency.

Innovation Solution

The dual propeller turbine design incorporates two propeller turbines on a common shaft with opposite axial force directions, eliminating the need for axial bearings by using roller bearings and optimizing water jet entry to minimize losses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If axial bearings are used to absorb axial force in propeller turbines, then the turbine can operate, but lubrication becomes difficult and losses increase at high revolutions

Engineering Contradiction:
Improveturbine operationVSAvoidbearing losses
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent employs two propeller turbines mounted on a common shaft with opposite axial force directions. The axial forces generated by the water jets on the basic and additional spiral blades are opposite to each other, creating a counterbalancing effect that eliminates the need for axial bearings and reduces power losses.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

Solution Approach 2:

The patent combines two propeller turbines on a common shaft, integrating them into a single unified structure. This merging allows the axial forces from both turbines to counterbalance each other, eliminating the need for separate axial bearing systems and reducing overall energy losses.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If axial bearings are used to absorb axial force, then the turbine can operate, but lubrication difficulty increases and efficiency decreases

Engineering Contradiction:
Improveturbine operationVSAvoidlubrication
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent employs two propeller turbines mounted on a common shaft with opposite axial force directions. The axial forces generated by the water jets on the basic and additional spiral blades are opposite to each other, creating a counterbalancing effect that eliminates the need for axial bearings and reduces power losses.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

Solution Approach 2:

The patent combines two propeller turbines on a common shaft, integrating them into a single unified structure. This merging allows the axial forces from both turbines to counterbalance each other, eliminating the need for separate axial bearing systems and reducing overall energy losses.

Inventive Principle:
Principle #5Merging (Combining)

3Device complexity

If single propeller turbine is used, then structure is simple, but power output is limited and diameter must increase for higher power

Engineering Contradiction:
Improveturbine structureVSAvoidpower output
Core Design Contradiction:
Device complexityVSPower

Solution Approach 1:

The patent combines two propeller turbines on a common shaft, integrating them into a single unified structure. This merging allows the axial forces from both turbines to counterbalance each other, eliminating the need for separate axial bearing systems and reducing overall energy losses.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces a second propeller turbine on the same shaft, adding a dimensional aspect to the power generation system. This allows the system to achieve higher power output by utilizing both turbines simultaneously while maintaining a compact configuration through the common shaft arrangement.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 design enhances efficiency by compensating axial forces, reduces power losses, and allows for higher power output without increasing diameter, suitable for both low and high pressure conditions.

Implementation Method 1

water enters in the form of a jet and is delivered to ladles mounted on the rim of a blade wheel

Methodology Applied
Scientific EffectJet: Jet

Implementation Method 2

The tangential component of the jet velocity on the ladles changes direction by 180 degrees, resulting in a force acting on each ladle

Methodology Applied
Scientific EffectImpact force: Impact Force

Implementation Method 3

A torque is generated on the blades when the axial force generated on the inclined surfaces of the spiral blades breaks up

Methodology Applied
Scientific EffectForce decomposition:

Implementation Method 4

the jet will be affected by centrifugal forces, which will cause the jet to spill over the blade surfaces

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 5

the passage of the initial jet through the distribution guide chamber, which directs the jet with its guide blades in such a manner that at every point of the entrance arc, the water will have radial and tangential velocity components

Methodology Applied
Scientific EffectFluid flow direction control:

Data Source

PatentEP4413250B1Dual propeller turbine
Publication Date: 2025.12.10 JSC ZAGO TECH
  • EP4413250B1 patent drawingFigure 1
  • EP4413250B1 patent drawingFigure 2~3b
  • EP4413250B1 patent drawingFigure 4~5

AI summary

A propeller turbine is provided that comprises basic spiral blades, two basic co-axial shafts on which said basic spiral blades are mounted, a basic water jet receiving and distributing chamber, and a basic adjustable reducing nozzle for generating the jet. The turbine further comprises additional spiral blades and two additional co-axial shafts on which said additional spiral blades are mounted, wherein the basic and additional spiral blades are arranged along a common axis; an additional water jet receiving and distributing chamber, and an additional adjustable redusing nozzle for generating a water jet.