Rotary Electric Machine Abnormality Diagnosis by Speed Range Segmentation
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Solution Overview
Problem
Existing abnormality diagnosis systems for rotary electric machines lack accuracy in identifying the occurrence site of anomalies, often misdiagnosing issues in bearings when they actually occur in other components like the main shaft.
Innovation Solution
An abnormality diagnosis system that includes vibration and speed sensors to measure and analyze data, using a database to record and compare vibration and rotational speed values over time, determining abnormalities based on thresholds within specific speed ranges to accurately identify the occurrence site.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If vibration values are monitored to diagnose bearing abnormality, then bearing degradation can be detected, but misdiagnosis may occur when abnormality exists in other components (main shaft, etc.)
Solution Approach 1:
The patent segments the vibration analysis by dividing the speed range into multiple ranges and analyzing vibration characteristics specific to each range. By comparing vibration values across different speed ranges, the system can identify whether abnormality originates from the bearing or other components, thus resolving the misdiagnosis problem while maintaining diagnosis accuracy.
2Measurement precision
If vibration monitoring is performed across all speed ranges, then comprehensive abnormality detection is achieved, but diagnosis accuracy decreases due to noise from unrelated speed ranges
Solution Approach 1:
The patent applies local quality by assigning different analysis methods to different speed ranges. Instead of uniformly analyzing all vibration data, the system focuses on specific speed ranges where bearing-related vibrations are most prominent, thereby improving measurement precision while avoiding unnecessary complexity from analyzing irrelevant data.
3Measurement precision
If excitation is applied to measure resonant frequency for high-accuracy diagnosis, then bearing degradation accuracy improves, but the system cannot diagnose abnormality in other components
Solution Approach 1:
The patent makes the vibration monitoring system universal by enabling it to diagnose multiple types of abnormality (bearing degradation, main shaft issues, etc.) through a single integrated approach. By analyzing vibration characteristics across multiple speed ranges without requiring separate excitation procedures, the system achieves both bearing-specific precision and broader diagnostic coverage.
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 system enables precise identification of abnormality occurrence sites in rotary electric machines, reducing the risk of misdiagnosis and allowing for timely maintenance or replacement of affected components.
Implementation Method 1
a vibration sensor that measures a vibration value of the bearing
Implementation Method 2
a speed sensor that measures a rotational speed value of the main shaft
Data Source
AI summary
The present invention provides an abnormality diagnosis system capable of identifying an abnormality occurrence site in a rotary electric machine by use of output of sensors mounted to a bearing of the rotary electric machine. The abnormality diagnosis system includes: a rotary electric machine that has a main shaft secured to a center of a rotor and supported by a bearing; a vibration sensor that measures a vibration value of the bearing; a speed sensor that measures a rotational speed value of the main shaft; and an abnormality diagnosis apparatus that diagnoses abnormality in the rotary electric machine based on the vibration value and the rotational speed value. The abnormality diagnosis apparatus includes: a database that records the vibration value, the rotational speed value, and measurement times of the vibration value and the rotational speed value, as a data group of one unit, the vibration value and the rotational speed value measured within a predetermined time period; and an abnormality determination section that makes determination of abnormality, if a first threshold is exceeded by a difference in maximum vibration value in one speed range of interest between a past data group and a newer data group of a plurality of data groups recorded in the database, and makes no determination of abnormality, even if the first threshold is exceeded by a difference in maximum vibration value outside the speed range of interest.