Cyclic Machine Component Monitoring for Variable-Speed Fault Detection

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Solution Overview

Problem

Existing condition monitoring methods for cyclically moving machine components, such as bearings and motors, lack accuracy and are complex due to assumptions about constant rotation speeds and localized damage, which can lead to underestimated or overestimated component lifetimes and hidden fault detection.

Innovation Solution

A method involving the registration of movement characteristics, generation of frequency distributions, segmentation into defined indexes, and comparison of reference term frequencies to accurately classify machine component status and detect impending breakdowns, allowing for timely maintenance without production disruptions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If traditional vibration analysis methods are used with assumptions of constant rotation speed and localized damage, then the monitoring process is simplified, but the measurement precision and reliability of fault detection deteriorate

Engineering Contradiction:

Improvemonitoring process complexityVSAvoidfault detection accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent segments the continuous vibration signal into discrete cycles corresponding to specific machine component rotations. By dividing the signal into individual cycles and analyzing each separately, the method captures variable speed characteristics without requiring constant speed assumptions, thereby improving measurement precision while maintaining manageable analysis complexity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent transforms the vibration analysis from frequency-domain methods (which assume constant speed) to time-domain cycle-by-cycle analysis. This parameter change allows the system to handle variable rotation speeds accurately, improving fault detection reliability without significantly increasing system complexity

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If empirical evaluation of motion characteristics is used, then the implementation is simpler, but the reliability of remaining lifetime estimation deteriorates

Engineering Contradiction:

Improveimplementation simplicityVSAvoidremaining lifetime estimation accuracy

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent replaces empirical evaluation methods with an automated computational approach that processes vibration signals through systematic cycle-by-cycle analysis. This substitution of manual/empirical methods with algorithmic processing improves the reliability of lifetime estimation while keeping the implementation straightforward through standard computing operations

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements continuous monitoring with feedback by comparing each cycle's vibration characteristics against established patterns and updating the assessment of component health status. This feedback mechanism provides reliable, real-time estimation of remaining lifetime without requiring complex manual intervention

Inventive Principle:

Principle #23Feedback

3Device complexity

If frequency domain analysis with fixed assumptions is used, then the analysis method is simpler, but the adaptability to variable speed profiles deteriorates

Engineering Contradiction:

Improveanalysis method complexityVSAvoidvariable speed profile handling

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent employs dynamic cycle-by-cycle analysis that adapts to varying rotation speeds by synchronizing the analysis with each actual machine component cycle. This dynamic approach allows the system to handle variable speed profiles effectively without requiring complex speed synchronization or transformation, maintaining analysis simplicity while improving adaptability

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS11953878B2Method and system for condition monitoring of a cyclically moving machine component

Publication Date: 2024.04.09 TETRA LAVAL HOLDINGS & FINANCE SA

AI summary

A method (1000) for condition monitoring is disclosed, comprising registering (1010) values (v1) of movement characteristics measured for cycles of motion of a cyclically moving machine, associating (1050) the occurrence of values in a frequency distribution (Fv1) of the values with respective defined indexes (a, b, c, . . . ) based on intervals, generating (1060) a word string (S) of the defined indexes corresponding to the occurrence of the values, segmenting (1070) said word string (S) into a sub-set of words (s1, s2, . . . , si), determining (1080) a frequency of the occurrence of the segmented words in said word string as a first reference term frequency (TF1), associated with a first machine status (M1), for subsequently registered set of values of movement characteristics, determining (1100) a subsequent term frequency (TFn), comparing (1110) the subsequent term frequency (TFn) with the first reference term frequency to determine a correlation with the first machine status.