Engine Rotor Rubbing Detection Using Speed and Acceleration Thresholds

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Solution Overview

Problem

Existing systems for identifying rubbing conditions in aircraft engine rotational equipment are not sufficiently effective, leaving room for improvement in detection and prevention of damage.

Innovation Solution

An assembly for an aircraft propulsion system that includes an engine with a rotational assembly, a rotation speed sensor, and a controller. The controller monitors rotational parameters, such as rotation speed and acceleration, to identify the presence or absence of a rubbing condition by comparing these parameters to identification thresholds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If existing systems for identifying rubbing conditions are used, then the detection capability is limited, but the system complexity and cost are reduced

Engineering Contradiction:
Improverubbing condition detection accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the rubbing condition detection into multiple independent monitoring parameters (rotation speed, acceleration, rate of change of acceleration) that can be measured and analyzed separately. Each parameter is monitored independently and then integrated to form a comprehensive diagnosis, allowing the system to achieve high detection accuracy through multiple simple measurements rather than one complex measurement system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically adjusts the identification threshold for rubbing conditions based on the current operating state of the engine. Instead of using a fixed threshold, the threshold is determined by real-time monitoring of rotation speed and acceleration, allowing the detection system to adapt to varying operational conditions and maintain high accuracy across different engine states without requiring complex recalibration procedures.

Inventive Principle:
Principle #15Dynamics

2Reliability

If existing rubbing condition identification methods are used, then damage prevention capability is insufficient, but the maintenance cost and operational simplicity are maintained

Engineering Contradiction:
Improveengine dependabilityVSAvoidmonitoring system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system performs preliminary detection of rubbing conditions by continuously monitoring rotation speed and acceleration parameters before actual damage occurs. By identifying abnormal patterns early through rate of change analysis, the system enables preventive maintenance actions to be taken before components suffer catastrophic failure, thereby improving engine reliability without requiring complex post-failure diagnostic equipment.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The monitoring system implements feedback by comparing real-time rotation speed and acceleration measurements against dynamically determined thresholds. When parameters exceed the threshold, the system generates alerts that feed back to operators or maintenance systems, enabling continuous improvement of engine reliability through ongoing monitoring and timely intervention rather than periodic inspections.

Inventive Principle:
Principle #23Feedback

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 enables early and accurate identification of rubbing conditions, thereby preventing damage to engine components, improving engine dependability, and reducing maintenance costs.

Implementation Method 1

The rotation speed sensor is configured to measure a rotation speed of the rotational assembly

Methodology Applied
Scientific EffectRotation speed measurement:

Implementation Method 2

the instructions, when executed by the processor, may further cause the processor to determine an acceleration of the rotational assembly using the measured rotation speed

Methodology Applied
Scientific EffectAcceleration determination:

Data Source

PatentEP4530438A1System and method for identifying rubbing conditions for engine rotational equipment
Publication Date: 2025.04.02 PRATT & WHITNEY CANADA CORP
  • EP4530438A1 patent drawingFigure 1
  • EP4530438A1 patent drawingFigure 2
  • EP4530438A1 patent drawingFigure 3

AI summary

An assembly for an aircraft propulsion system includes an engine (22), a rotation speed sensor (72B), and a controller (24). The engine (22) includes a rotational assembly (46). The rotational assembly (46) includes a bladed turbine rotor (54) and a shaft (50) configured for rotation about a rotational axis (44). The rotation speed sensor (72B) is disposed at the rotational assembly (46). The rotation speed sensor (72B) is configured to measure a rotation speed of the rotational assembly (46). The controller (24) is configured to monitor a rotational parameter of the rotational assembly (46) while the rotational assembly (46) is rotating. The rotational parameter is determined using the measured rotation speed from the rotation speed sensor (72B). The controller (24) is further configured to cause the processor (68) to identify a presence or an absence of a rubbing condition for the rotational assembly (46) by comparing the rotational parameter to an identification threshold for the rotational parameter. The presence of the rubbing condition is identified where the rotational parameter exceeds the identification threshold.