A New Model for Estimating Vibrations Generated in the Defective Rolling Element Bearings

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Mehdi Behzad ◽  
Abbas Rohani Bastami ◽  
David Mba
Keyword(s):  
High Frequency ◽  
Rolling Element Bearings ◽  
Stochastic Excitation ◽  
Vibration Level ◽  
Metallic Contact ◽  
New Model ◽  
Proposed Model ◽  
Vibration Model ◽  
Rolling Element ◽  
Defective Area

Prediction of the vibration response due to defects on rolling element bearings requires having an accurate representative vibration model. In this paper, a new model for vibration generation in the rolling element bearings has been introduced. The proposed model assumes a stochastic source of vibration excitation, which is produced as a result of metallic contact between bearing elements during rolling. This model explains high frequency vibration in the acceleration spectrum clearly. When a defect grows in the bearing, the roughness of the contacting surfaces increases locally and stochastic excitation becomes stronger in the defective area. The increased vibration level at the defective area is a good indicator of bearing faults. A numerical simulation of the proposed model was validated with experimental results.

Vibration model of rolling element bearings in a rotor-bearing system for fault diagnosis

2013 ◽  
Vol 332 (8) ◽  
pp. 2081-2097 ◽  
Author(s):  
Feiyun Cong ◽  
Jin Chen ◽  
Guangming Dong ◽  
Michael Pecht
Keyword(s):  
Fault Diagnosis ◽  
Rolling Element Bearings ◽  
Vibration Model ◽  
Rolling Element ◽  
Rotor Bearing ◽  
Bearing System

Modelling of impulse currents in mechanical rolling element bearings

2012 ◽  
Vol 31 (6) ◽  
pp. 1575-1589 ◽  
Author(s):  
Hendrik Kolbe ◽  
Annette Muetze ◽  
Kay Hameyer
Keyword(s):  
Contact Zone ◽  
High Frequency ◽  
Single Step ◽  
Reduced Model ◽  
Extended Model ◽  
Rolling Element Bearings ◽  
Content Type ◽  
High Frequency Discharge ◽  
Starting Point ◽  
Rolling Element

PurposeThe purpose of this paper is to contribute toward the modelling of the microscopic interaction between high‐frequency discharge bearing currents and rolling element bearings in the contact zone. It also aims to develop a reduced model that can serve as a starting point for further developments.Design/methodology/approachThe complexity of an ideal comprehensive model is identified and analysed. Based thereon, a reduced model is developed.FindingsThe true system is highly complex and cannot be solved in a single‐step approach. The proposed reduced model allows the explanation of the melting of the bearing surfaces under the influence of the high‐frequency currents. It also provides a starting point for the development of an extended model.Research limitations/implicationsThe model excludes the dynamic rolling movement of the bearing. The development of the frosting and fluting observed on the bearing running surfaces can only be explained in parts.Practical implicationsThe melting of the bearing race surface can be modelled and thereby explained. The proposed model forms a good basis for further work toward an extended model to explain the high‐frequency bearing current bearing damage mechanism.Originality/valueThe paper offers a method to model the microscopic interaction between high‐frequency discharge bearing currents and rolling element bearings in the contact zone. This phenomenon has not yet been modelled to this extent. Such a model – and the understanding brought forth from it – allows the reduction in the cost for safe operation of modern variable speed drive systems.

A Stochastic Model for Simulation and Diagnostics of Rolling Element Bearings With Localized Faults

2003 ◽  
Vol 125 (3) ◽  
pp. 282-289 ◽  
Author(s):  
J. Antoni ◽  
R. B. Randall
Keyword(s):  
Spectral Characteristics ◽  
Vibration Signal ◽  
Spectral Signature ◽  
Rolling Element Bearings ◽  
Envelope Analysis ◽  
Analysis Technique ◽  
Proposed Model ◽  
Rolling Element ◽  
Excitation Force ◽  
Localized Faults

This paper addresses the stochastic modeling of the vibration signal produced by localized faults in rolling element bearings and its use for diagnostic purposes. The aim is essentially to provide a better understanding of the recognized “envelope analysis” technique as classically used in the diagnostics of rolling element bearings, and incidentally give theoretical proofs for the specific features of envelope spectra as obtained from experimental data. The proposed model may also prove useful for simulation purposes. First, the excitation force generated by a defect is modeled as a random point process and its spectral signature is derived analytically. Then its transmission through the bearing is investigated in detail in order to find the spectral characteristics of the resulting vibration signal. The analysis finally gives sound justification for “squared” envelope analysis and the type of spectral indicators that should be used with it.

Modelling and Analysis of Capacitive Effects in a High Frequency Coaxial Transformer

2012 ◽  
Vol 466-467 ◽  
pp. 607-611
Author(s):  
Xiao Guang Yang
Keyword(s):  
Energy Storage ◽  
Electromagnetic Interference ◽  
High Frequency ◽  
Electric Energy ◽  
Experimental Results ◽  
Voltage Distribution ◽  
New Model ◽  
Electric Energy Storage ◽  
Proposed Model ◽  
Good Agreement

A new model is proposed for analyzing the capacitive effects in a newly developed high frequency coaxial transformer (HFCT). The proposed model can describe both the electric energy storage and common-mode (CM) electromagnetic interference (EMI) noise behaviors of a transformer, considering the voltage distribution in the HFCT windings. To determine the parameters of the model, a parasitic capacitance network is developed to describe the HFCT’s real winding’s structure, and the distributed parasitic capacitances of the network are evaluated using FEM based on the theory of capacitances in a multi-conductor system. The calculated inter-capacitance of the HFCT is in good agreement with the experimental results.

Dynamic Modeling of Rolling Element Bearings With Surface Contact Defects Using Bond Graphs

2010 ◽  
Vol 133 (1) ◽  
Author(s):  
Mohsen Nakhaeinejad ◽  
Michael D. Bryant
Keyword(s):  
Three Dimensional ◽  
Surface Profile ◽  
Rolling Element Bearing ◽  
Rolling Element Bearings ◽  
Bond Graphs ◽  
Outer Race ◽  
Proposed Model ◽  
Rolling Element ◽  
Type Size ◽  
Localized Faults

Multibody dynamics of healthy and faulty rolling element bearings were modeled using vector bond graphs. A 33 degree of freedom (DOF) model was constructed for a bearing with nine balls and two rings (11 elements). The developed model can be extended to a rolling element bearing with n elements and (3×n) DOF in planar and (6×n) DOF in three dimensional motions. The model incorporates the gyroscopic and centrifugal effects, contact elastic deflections and forces, contact slip, contact separations, and localized faults. Dents and pits on inner race and outer race and balls were modeled through surface profile changes. Bearing load zones under various radial loads and clearances were simulated. The effects of type, size, and shape of faults on the vibration response in rolling element bearings and dynamics of contacts in the presence of localized faults were studied. Experiments with healthy and faulty bearings were conducted to validate the model. The proposed model clearly mimics healthy and faulty rolling element bearings.

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.

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