Electrical Machine Signal Analysis for Rotating Machinery Vibration

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Solution Overview

Problem

Existing systems fail to detect early and reliably vibrations caused by gap-dependent forces in rotating machinery, particularly in aircraft engines, which can lead to increased wear, performance deterioration, and potential failure due to oil film-induced vibrations and misalignment issues.

Innovation Solution

A system utilizing an electrical machine with rotors and stators to provide signals indicative of motion and force between components, allowing for the detection and monitoring of vibration signatures through an analysis unit that identifies characteristic frequencies and generates commands for control systems to address potential misalignment and instability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional vibration detection systems are used, then they can detect vibrations in rotating machinery, but they fail to detect early and reliably vibrations caused by gap-dependent forces

Engineering Contradiction:
Improvevibration detection precisionVSAvoiddetection reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent introduces an intermediary signal processing approach by using the electrical machine's own operational signals (current, voltage, torque) as mediators to detect vibrations. Instead of relying on external vibration sensors that directly measure mechanical vibrations, the system uses electrical signals that are indirectly affected by mechanical vibrations through the fluid film coupling, thereby achieving more reliable early detection of gap-dependent forces.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces traditional mechanical vibration sensing systems with an electrical signal-based detection system. By substituting direct mechanical vibration measurement with electrical signal analysis from the motor drive, the system achieves improved measurement precision and reliability in detecting early-stage vibrations caused by gap variations in fluid-film bearings.

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

2Loss of time

If existing vibration monitoring systems are implemented, then they can monitor rotating machinery, but they cannot identify misalignment issues before significant damage occurs

Engineering Contradiction:
Improvemaintenance timeVSAvoidmisalignment detection precision
Core Design Contradiction:
Loss of timeVSMeasurement precision

Solution Approach 1:

The patent enables preliminary detection of misalignment and vibration issues by continuously monitoring electrical signals from the motor drive before mechanical damage occurs. The system analyzes changes in current, voltage, and torque signals that precede significant mechanical degradation, allowing maintenance to be scheduled in advance rather than reacting to failure symptoms.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements continuous feedback monitoring of electrical signals from the motor drive, comparing actual signals against expected operational patterns. This feedback mechanism enables real-time detection of deviations caused by misalignment or gap variations, providing early warning signals that trigger maintenance actions before damage progresses.

Inventive Principle:
Principle #23Feedback

3Difficulty of detecting and measuring

If conventional detection methods are used, then they can monitor general vibrations, but they fail to detect oil film-induced vibrations and misalignment issues

Engineering Contradiction:
Improvevibration detection difficultyVSAvoiddetection reliability
Core Design Contradiction:
Difficulty of detecting and measuringVSReliability

Solution Approach 1:

The patent enables the electrical machine to self-diagnose vibration and misalignment issues by utilizing its own operational electrical signals. The motor drive system serves its dual function of both actuation and sensing, eliminating the need for separate detection systems and providing reliable detection of oil film-induced vibrations through analysis of its self-generated electrical signals.

Inventive Principle:
Principle #25Self-service

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 precise and early detection of vibrations, reducing the risk of failure and extending the lifespan of journal bearings and other components by identifying misalignment issues before significant damage occurs, thereby improving maintenance efficiency and reducing costs.

Implementation Method 1

unbalanced magnetic forces are induced in the electrical machine as a consequence of asymmetrical gap-dependent forces being generated on other rotors

Methodology Applied
Scientific EffectMagnetic force: Lorentz Force

Implementation Method 2

detect a vibration signature of the rotatable component with respect to the other component based on the signals received from the electrical machine

Methodology Applied
Scientific EffectVibration detection: Vibration

Data Source

PatentEP3992594A1System and method for detecting vibrations in rotating machinery
Publication Date: 2022.05.04 ROLLS ROYCE DEUT LTD & CO KG
  • EP3992594A1 patent drawingFigure 1
  • EP3992594A1 patent drawingFigure 2~3
  • EP3992594A1 patent drawingFigure 4

AI summary

Embodiments of the invention are shown in the figures, where a system is shown, the system (50) comprising: two or more drivelines (90A-90D), each including a rotatable component (91, 92) rotatable about a rotational axis relative to another component (91, 92, 72); two or more electrical machines (70), each having a rotor and a stator rotatable with respect to one another, the rotor being arranged to drive and/or to be driven by a part of one of the drivelines (90A-90D), the electrical machines (70) being adapted to provide signals indicative for a motion and/or a force between the respective rotor (71) and the stator (72) and/or a torque applied on the respective rotor (71); and an analysis unit (80) adapted to receive the signals and to detect a vibration signature of each of the rotatable components of the two or more drivelines (90A-90D) with respect to the respective other component based on the signals..