Rotating Machine Contact Position Detection via Phase Difference

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Solution Overview

Problem

Existing technologies for detecting abnormalities in rotating machines, such as contact between rotors and the casing, struggle to accurately specify the contact position during rotation, leading to inefficiencies in maintenance and diagnosis.

Innovation Solution

An abnormality detecting apparatus with multiple sensors positioned around a rotating machine calculates phase differences between sensor signals to determine contact positions by utilizing phase-only correlation functions and time-frequency analysis, allowing for precise identification of contact locations between rotors and the casing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple sensors are arranged at different locations to detect elastic waves, then contact position specification capability is improved, but device complexity increases

Engineering Contradiction:
Improvecontact position specification accuracyVSAvoidsensor arrangement complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The detection system is segmented into multiple independent sensors positioned at different locations around the rotating machine. Each sensor independently detects elastic waves from potential contact points, and the control device processes signals from each sensor separately to determine phase differences and locate contact positions accurately.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control device acts as an intermediary that receives signals from multiple sensors, performs phase difference calculations, and synthesizes this information to specify contact positions. This intermediary processing layer manages the complexity of multiple sensors while providing accurate contact location information.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If phase difference calculation is performed using multiple sensor signals, then contact position determination accuracy is improved, but signal processing complexity increases

Engineering Contradiction:
Improvecontact position determination accuracyVSAvoidsignal processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system utilizes elastic wave vibrations generated by rotor contacts as the detection mechanism. By analyzing the phase differences of these vibration signals from multiple sensors, the system accurately determines contact positions without requiring complex mechanical intervention.

Inventive Principle:
Principle #18Mechanical vibration

Solution Approach 2:

The patent replaces direct mechanical contact detection methods with elastic wave-based detection. Instead of using mechanical probes or direct physical measurement, the system uses acoustic/elastic wave signals and their phase relationships to infer contact positions, reducing mechanical complexity while improving measurement capability.

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

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 approach enables accurate and efficient specification of contact positions, enhancing maintenance by providing detailed positional information of rotor contacts, thereby improving diagnostic accuracy and operational efficiency.

Implementation Method 1

a plurality of sensors each of which detects an elastic wave generating in the rotating machine having a rotor during rotation of the rotor

Methodology Applied
Scientific EffectElastic wave: Vibration

Data Source

PatentEP3193156B1Rotating machine abnormality detection device, rotating machine abnormality detection method, and rotating machine
Publication Date: 2019.10.02 KOBE STEEL LTD
  • EP3193156B1 patent drawingFigure 1
  • EP3193156B1 patent drawingFigure 2
  • EP3193156B1 patent drawingFigure 3

AI summary

An abnormality detecting apparatus (10) for a rotating machine includes: a calculating part (15) which calculates a phase difference between signals respectively output from two sensors of one or more sets, the one or more sets being predetermined combinations of two sensors among the plurality of sensors, the plurality of sensors each of which detects an elastic wave generating in the rotating machine (1) having a rotor during rotation of the rotor, the sensors being arranged at predetermined different locations of the rotating machine (1); a storing part (16) which stores in advance information concerning a relationship between a phase difference and a contact position when a contact occurs during the rotation of the rotor, regarding the one or more sets; and a specifying part (17) which specifies a contact position by using a phase difference calculated by the calculating part (15) and the information stored in the storing part (16).