Phonic Wheel Synchrophasing for Propeller Phase Precision

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Solution Overview

Problem

Existing synchrophasing techniques for turboprop engines based on missing teeth are inaccurate and require additional equipment, necessitating improvements for effective vibration and noise reduction in aircraft.

Innovation Solution

A system and method for synchrophasing multi-engine aircraft that involves transmitting position signals from propellers to a central control system to adjust operating parameters, maintaining predetermined phase angles between propellers, and utilizing a phonic wheel with angled position markers for precise rotational position detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If missing tooth techniques are used for synchrophasing, then relative phase information can be obtained, but measurement precision deteriorates and device complexity increases due to additional equipment requirements

Engineering Contradiction:
Improvephase measurement precisionVSAvoidequipment complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the phase measurement function from complex external equipment and integrates it into the existing phonic wheel structure by simply removing one tooth, thereby achieving phase information detection without additional complex devices

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of adding markers to indicate phase position, the patent inverts the approach by removing one tooth from the uniform tooth pattern, creating a 'missing tooth' that generates distinctive signals for phase detection

Inventive Principle:
Principle #13The other way round (Inversion)

2Measurement precision

If missing tooth techniques are used for synchrophasing, then phase information can be detected, but measurement precision deteriorates due to accuracy limitations

Engineering Contradiction:
Improvephase detection accuracyVSAvoidsynchrophasing accuracy
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent employs feedback mechanisms where the control system continuously monitors the rotational phase of propellers through the missing tooth signals and dynamically adjusts engine parameters to maintain optimal phase relationships, thereby improving both accuracy and reliability

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces mechanical phase measurement methods with electronic detection systems that read the missing tooth patterns, substituting mechanical complexity with electronic precision for more accurate phase detection

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

Data Source

PatentEP3967607B1Propeller blade synchrophasing using phonic wheel
Publication Date: 2023.08.30 PRATT & WHITNEY CANADA CORP
  • EP3967607B1 patent drawingFigure 1
  • EP3967607B1 patent drawingFigure 2
  • EP3967607B1 patent drawingFigure 3

AI summary

Herein provided are systems and methods for synchrophasing multi-engine aircraft. A phonic wheel (204) is coupled to a first propeller (130) of a first engine (110) of the aircraft. A sensor (212) is disposed and configured for producing a signal in response to passage of first and second position markers (420) on the phonic wheel (204). A control system (220) is communicatively coupled to the sensor (212) for obtaining the signal, and configured for: determining an expected delay between two subsequent signal pulses of the signal; identifying from within the plurality of signal pulses a particular pulse associated with the second position marker (420); determining, based on a particular time at which the particular pulse associated with the second position marker (420) was produced, that a rotational position of the first propeller (130) corresponds to a reference position at the particular time; and performing at least one synchrophasing operation for the aircraft based on the rotational position of the first propeller (130).