scholarly journals Time-Domain Based Quantification of Surface Degradation for Better Monitoring of the Health Condition of Ball Bearings

Vibration ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 172-191
Author(s):  
Ayman Salem ◽  
Abdelrahman Aly ◽  
Sadok Sassi ◽  
Jamil Renno
Keyword(s):  
Time Domain ◽  
Health Condition ◽  
Second Phase ◽  
Ball Bearings ◽  
Test Rig ◽  
Bearing Defects ◽  
Defect Growth ◽  
Rolling Element ◽  
Innovative Solution ◽  
The Time Domain

This research aims to analyze the vibration response of damaged rolling element bearings experimentally and to assess their degree of degradation by examining parameters extracted from the time domain. This task was accomplished in three phases. In the first phase, a test rig was carefully designed and precisely manufactured. In particular, an innovative solution for rapidly mounting and dismounting bearings on the supporting shaft was tested and used successfully. In the second phase, a specific technique of seeding defects inside the ball bearings was developed. In the last phase, damaged bearings (and healthy ones serving as a reference) were installed on the test rig, and different vibration measurements were taken. The results obtained from this work show that different parameters could be extracted from the time domain. In addition to the six common indicators (peak, root mean square, crest factor, kurtosis value, impulse factor, and shape factor), four hybrid new ones have been proposed (Talaf, Thikat, Siana and, Inthar). The experimental results confirm the well-known efficiency of kurtosis in the detection of bearing defects. However, the newly proposed parameters were found to be more responsive to defect growth.

Experimental investigation on time-domain features in the diagnosis of rolling element bearings by acoustic emission

2021 ◽  
pp. 107754632110161
Author(s):  
Aref Aasi ◽  
Ramtin Tabatabaei ◽  
Erfan Aasi ◽  
Seyed Mohammad Jafari
Keyword(s):  
Acoustic Emission ◽  
Condition Monitoring ◽  
Time Domain ◽  
Central Moment ◽  
Rolling Element Bearings ◽  
Test Rig ◽  
Acoustic Emission Sensor ◽  
Outer Race ◽  
Common Time ◽  
Rolling Element

Inspired by previous achievements, different time-domain features for diagnosis of rolling element bearings are investigated in this study. An experimental test rig is prepared for condition monitoring of angular contact bearing by using an acoustic emission sensor for this purpose. The acoustic emission signals are acquired from defective bearing, and the sensor takes signals from defects on the inner or outer race of the bearing. By studying the literature works, different domains of features are classified, and the most common time-domain features are selected for condition monitoring. The considered features are calculated for obtained signals with different loadings, speeds, and sizes of defects on the inner and outer race of the bearing. Our results indicate that the clearance, sixth central moment, impulse, kurtosis, and crest factors are appropriate features for diagnosis purposes. Moreover, our results show that the clearance factor for small defects and sixth central moment for large defects are promising for defect diagnosis on rolling element bearings.

The Effect of Inlet Grooves and Swirl on the Dynamics of Long Annular Seals in Centrifugal Pumps

1993 ◽  
Author(s):  
Mohamed Ismail ◽  
R. David Brown ◽  
David France
Keyword(s):  
Rolling Element Bearings ◽  
Rigid Rotor ◽  
Centrifugal Pumps ◽  
Test Rig ◽  
Singular Value Decomposition Method ◽  
Forcing Function ◽  
Rolling Element ◽  
The Time Domain ◽  
Value Decomposition ◽  
Annular Seals

Abstract This paper describes additional results from a continuing research program which aims to identify the dynamics of long annular seals in centrifugal pumps. A seal test rig designed to experimentally identify dynamic coefficients using a least-squares technique based on the singular value decomposition method. The analysis is carried out in the time domain using a multifrequency forcing function. The experimental method relies on the forced excitation of a flexibly supported stator by two hydraulic shakers. A rigid rotor supported in rolling element bearings runs through the stator. The only physical connection between shaft and stator is a pair of annular gaps filled with pressurised water discharged axially. The experimental coefficients obtained from the tests are compared with theoretical values.

Identification of Bearing Defects in Hybrid Thrust Ball Bearings by Vibration Analysis

2015 ◽  
Vol 825-826 ◽  
pp. 844-851 ◽  
Author(s):  
Arne Ziebell ◽  
Oskar Schöppl ◽  
Roland Haubner ◽  
Thomas Konegger
Keyword(s):  
Vibration Analysis ◽  
Relevant Information ◽  
Optimal Operation ◽  
Ball Bearings ◽  
Test Rig ◽  
Successful Operation ◽  
Bearing Defects ◽  
The Status ◽  
Key Aspects

Hybrid ball bearings, consisting of metallic washers in combination with ceramic bearing balls, feature a variety of significant advantages in comparison to standard steel bearings, including mechanical properties and reduced friction during operation. Key aspects for a successful operation are a prevention of defects of both balls and washers, as well as the knowledge of critical and optimal operation parameters. This relevant information can be obtained through test rig trials, where vibration analysis has found to be a versatile and efficient tool for the characterization of the operational status. In this contribution, hybrid thrust ball bearings with Si3N4 balls are investigated. After an introduction of defined damages in different parts of the bearing, test rig trials were conducted, and the vibration behavior during operation was compared to new, unused bearings. The characteristic vibrational frequencies, obtained through a variety of software-based filter and analysis algorithms, were correlated with materialographic investigations of failed bearings. The proposed method was shown to yield valuable information about damage morphologies and, subsequently, about the status of the bearing during operation.

scholarly journals Multifault Diagnosis of Rolling Element Bearings Using a Wavelet Kurtogram and Vector Median-Based Feature Analysis

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Phuong H. Nguyen ◽  
Jong-Myon Kim
Keyword(s):  
Wavelet Packet ◽  
Health Condition ◽  
Rolling Element Bearing ◽  
Feature Analysis ◽  
Linear Discriminant ◽  
Bearing Fault ◽  
Fault Features ◽  
Rolling Element ◽  
Vector Median ◽  
The Time Domain

This paper presents a comprehensive multifault diagnosis methodology for incipient rolling element bearing failures. This is done by combining a wavelet packet transform- (WPT-) based kurtogram and a new vector median-based feature analysis technique. The proposed approach first extracts useful features that are characteristic of the bearing health condition from the time domain, frequency domain, and envelope power spectrum of incoming acoustic emission (AE) signals by using a WPT-based kurtogram. Then, an enhanced feature analysis approach based on the linear discriminant analysis (LDA) technique is used to select the most discriminant bearing fault features from the original feature set. These selected fault features are used by a Naïve Bayes (NB) classifier to classify the bearing fault conditions. The performance of the proposed methodology is tested and validated under various bearing fault conditions on an experimental test rig and compared with conventional state-of-the-art approaches. The proposed bearing fault diagnosis methodology yields average classification accuracies of 91.11%, 96.67%, 98.89%, 99.44%, and 98.61% at rotational speeds of 300, 350, 400, 450, and 500 rpm, respectively.

Comparison of denoising methods for the early detection of fatigue bearing defects by vibratory analysis

2011 ◽  
Vol 17 (13) ◽  
pp. 1983-1993 ◽  
Author(s):  
F Bolaers ◽  
O Cousinard ◽  
P Estocq ◽  
X Chiementin ◽  
J-P Dron
Keyword(s):  
Early Detection ◽  
Background Noise ◽  
Good Condition ◽  
Ball Bearings ◽  
Crest Factor ◽  
Vibratory Signal ◽  
Bearing Defects ◽  
Vibratory Analysis ◽  
Rolling Element ◽  
Random Impulse

The aim of this article is to show the interest of three major denoising methods for the improvement of the sensitivity of scalar indicators (crest factor, kurtosis) within the application of conditional maintenance by vibratory analysis on ball bearings. The case of a bearing in good condition of use is considered. The distribution of amplitudes in the vibratory signal is of the Gaussian kind. When the bearing is damaged, the appearance of spalling comes to disturb this signal, modifying this distribution. This modification is due to the presence of periodical impulses produced each time a rolling element meets a discontinuity on its way. Nevertheless, the presence of background noise induced by random impulse excitations can have an influence on the values of these temporal indicators. The denoising of these signals allows to improve the sensitivity of these indicators and to increase the reliability of the diagnosis.

Modelling and Validation of a Rotor System With Ball Bearings

2010 ◽  
Author(s):  
Onur Cakmak ◽  
Kenan Y. Sanliturk
Keyword(s):  
Experimental Data ◽  
Theoretical Model ◽  
Ball Bearing ◽  
Ball Bearings ◽  
Test Rig ◽  
Transform Method ◽  
Order Tracking ◽  
Bearing Defects ◽  
Gyroscopic Effects ◽  
Short Time

In this paper, a dynamic model of a rotor-ball bearing system is developed in Msc. ADAMS commercial software. Contacts between the balls and the rings are modelled according to Hertzian theory. The bearing model is capable of representing the effects of bearing defects and internal clearances. When they are coupled with the rotor structures, bearings without any defect can also cause excessive vibrations due to the resonance characteristics of the system. In order to demonstrate these characteristics the rotor itself is modelled as a flexible shaft and a disc positioned at the free end of the shaft. The rotor-ball bearing model developed here is capable of representing the gyroscopic effects and the behaviour of the system under different unbalance conditions. Various case studies are performed and Campbell diagrams are obtained by using short-time Fourier transform method. A test rig consisting of two ball bearings, a shaft and a disc is also designed and developed so as to validate the theoretical model using experimental data. The test rig is developed in such a way that all of the elements are easy to assemble/disassamble, allowing quick observation of the system’s dynamic behaviour for different parameters including imbalance, internal clearance and bearing defects. Modal analysis and order tracking analysis were carried out using the test rig. Both the modal results and Campbell diagrams obtained using experimental data are compared with their theoretical counterparts. In the light of the experimental data, the theoretical model is validated for the purpose of further analyses and research.

Fault Detection Through Vibration Signal Analysis of Rolling Element Bearing in Time Domain

2017 ◽  
pp. 208-234
Author(s):  
Pankaj Gupta ◽  
M. K. Pradhan
Keyword(s):  
Frequency Domain ◽  
Time Domain ◽  
Measurement Techniques ◽  
Industrial Applications ◽  
Rolling Element Bearing ◽  
Rotating Machines ◽  
Bearing Defects ◽  
Rolling Element ◽  
Vibration Signal Analysis ◽  
Critical Components

Mechanical failure prevention and condition monitoring have been one of the concerns of mechanical engineers in recent years due to the personal safety, cost of failure, reliability and downtime issues of equipment. Rotating machines are one of the most important actuators in the industrial applications as well as in every day applications. Rolling element bearings are very critical components of rotating machines and the presence of defects in the bearing may lead to failure of machines. Hence, early identification of such defects along with the severity of damage under operating condition of the bearing may avoid malfunctioning and breakdown of machines. Defective bearings are source of vibration and these vibration signals can be used to assess the faulty bearings. This chapter presents the brief review of recent trends in research on bearing defects, sources of vibration and vibration measurement techniques in time domain, frequency domain and time-frequency domain. Detailed explanation of defect detection through scalar indicators in time domain.

Fault Diagnosis and Analysis for Marine Planetary Gearbox

2009 ◽  
Vol 419-420 ◽  
pp. 149-152 ◽  
Author(s):  
Li Dong Jiang ◽  
Shan Chang ◽  
Guang Hao Dai ◽  
Zhen Rong Zhu
Keyword(s):  
Fault Diagnosis ◽  
Time Domain ◽  
Engineering Application ◽  
Vibration Signal ◽  
Frequency Domain Analysis ◽  
Load Test ◽  
Test Rig ◽  
Theory Analysis ◽  
Planetary Gearbox ◽  
The Time Domain

The abnormal noise was found in a marine planetary gearbox during the experiment. Then, the load test of the gearbox was done on a gearbox test rig and the vibration signal was measured and collected. The fault of the gearbox was analyzed by the time domain and frequency domain analysis. The trouble part was diagnosed and treated. The method used in this paper combined the theory analysis with engineering application. Simultaneously, it has provided a properly feasible method and valuable reference for the fault diagnosis of planetary gearbox.

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