Turbine Drive Arm Connection for Failure Detection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing turbine arrangements in gas turbine engines fail to detect failures between the first axial end of the turbine rotors and the drive arm connection, leading to potential uncontrolled acceleration and debris release, as the speed measurement system does not account for disconnected turbine rotors.

Innovation Solution

The turbine arrangement is modified by repositioning the drive arm to connect between the turbine shaft and the first turbine rotor, ensuring that any failure affects the measured rotational speed, allowing for early detection and implementation of mitigation actions such as reducing or shutting off fuel flow to prevent debris release.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the drive arm is connected to an intermediate turbine rotor, then the turbine arrangement can operate with multiple rotors, but failures between the first axial end and the drive arm connection cannot be detected

Engineering Contradiction:

Improveturbine operation capabilityVSAvoidfailure detection capability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

Instead of connecting the drive arm to an intermediate rotor as conventionally done, the patent inverts the connection strategy by ensuring the drive arm connection point is positioned such that any failure in the turbine rotors will affect the rotational speed measurement. This inversion of the conventional connection approach enables reliable failure detection while maintaining turbine operation capability.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent implements a feedback mechanism where the rotational speed of the turbine shaft is continuously measured and compared against expected speed ranges. When the measured speed falls outside the expected range, indicating a potential failure, the system triggers an alarm or shuts down the turbine. This feedback loop ensures that failures are detected and addressed promptly.

Inventive Principle:

Principle #23Feedback

2Measurement precision

If the rotational speed is measured at the turbine shaft, then the speed can be monitored continuously, but failures of disconnected turbine rotors remain undetected

Engineering Contradiction:

Improverotational speed measurementVSAvoidfailure detection information

Core Design Contradiction:

Measurement precisionVSLoss of information

Solution Approach 1:

The patent introduces an intermediary comparison mechanism that mediates between the raw rotational speed measurement and the failure detection requirement. By comparing the measured speed against expected speed ranges derived from turbine characteristics and operating conditions, the system extracts failure detection information that would otherwise be lost in the continuous speed measurement data.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If mitigation actions are implemented rapidly, then engine safety is improved, but false triggers may occur due to normal operational variations

Engineering Contradiction:

Improveengine safetyVSAvoidcontrol logic complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies partial action by implementing a tiered response system. Instead of immediately triggering full mitigation actions for any speed deviation, the system first compares the measured speed against expected ranges. Only when the deviation exceeds predetermined thresholds does the system trigger mitigation actions such as alarm signals or fuel flow reduction. This partial action approach reduces false triggers while maintaining rapid response capability for genuine failures.

Inventive Principle:

Principle #16Partial or excessive 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

Enables rapid detection of turbine acceleration and failure, allowing for timely mitigation actions to prevent uncontrolled debris release and ensuring engine safety by correlating measured speed with expected or threshold speeds, minimizing false triggers and maintaining effective reaction times.

Implementation Method 1

The measurement system comprises a speed measurement system

Methodology Applied

Scientific EffectSpeed measurement:

Implementation Method 2

The measurement system may comprise a phonic wheel and a magnetic inductance speed sensor

Methodology Applied

Scientific EffectMagnetic inductance: Electromagnetic Induction

Data Source

PatentEP3266990B1A turbine arrangement

Publication Date: 2021.02.24 ROLLS ROYCE PLC

Figure 1~2
Figure 3

AI summary

A turbine arrangement (30) for a gas turbine engine (10) comprising a turbine shaft (44). An axial array (34) of turbine rotors (32), having a first axial end and a second axial end. A drive arm (58) coupled between the turbine shaft (44) and the first axial end. A measurement system (50) arranged to measure a parameter of the turbine arrangement (30), the measurement system (50) positioned at the second axial end. The parameter may be rotational speed.