Transient Rotordynamic Modeling of Rolling Element Bearing Systems

2002 ◽  
Vol 124 (4) ◽  
pp. 984-991 ◽  
Author(s):  
A. Liew ◽  
N. Feng ◽  
E. J. Hahn
Keyword(s):  
Rolling Element Bearing ◽  
Hertzian Contact ◽  
Rolling Element Bearings ◽  
Test Rig ◽  
Centrifugal Load ◽  
Deep Groove ◽  
Rolling Element ◽  
Rolling Elements ◽  
Element Bearing ◽  
Bearing Preload

Nonlinearity effects in rolling element bearings arise from Hertzian contact force deformation relationships, clearance between rolling elements and races, and the bearing-to-housing clearance. Assuming zero bearing-to-housing clearance, a simplified earlier analysis showed that rotor bearing systems (RBSs) with deep groove ball bearings can give rise to chaotic motion and jump. This paper extends the bearing model to include rolling element centrifugal load, angular contacts and axial dynamics; and illustrates their effects in a rigidly supported rigid RBS and a flexibly supported flexible RBS, the latter modeling an existing test rig. Results are presented on the effect of bearing preload on the unbalance response up to a speed of 18,000 rpm.

Transient Rotordynamic Modeling of Rolling Element Bearing Systems

2001 ◽  
Author(s):  
A. Liew ◽  
N. S. Feng ◽  
E. J. Hahn
Keyword(s):  
Rolling Element Bearing ◽  
Hertzian Contact ◽  
Centrifugal Load ◽  
Linear Behavior ◽  
Deep Groove ◽  
Rolling Element ◽  
Rolling Elements ◽  
Load Effects ◽  
Element Bearing ◽  
Bearing Preload

Non-linearity effects in rolling element bearings may arise from the Hertzian contact force deformation relationship, the presence of clearance between the rolling elements and the bearing races, and the bearing to housing clearance. Assuming zero bearing to housing clearance and ignoring rolling element centrifugal load effects, it has been shown in earlier work that Rotor Bearing Systems (RBSs) with deep groove ball bearings can give rise to non-linear behavior such as chaotic motion and jump. This paper extends the bearing model to include rolling element centrifugal load, angular contacts and axial dynamics. The effect of more sophisticated bearing models is illustrated in both a rigidly supported rigid RBS and a flexibly supported flexible RBS, the latter being a model of a test rig designed to simulate an aircraft mounted accessory drive unit. Results are presented on the effect of bearing preload on the unbalance response up to a speed of 18,000 rpm.

Diagnosis of Rolling-Element Bearings Failure by Localized Electrical Current Between Track Surfaces of Races and Rolling-Elements

2002 ◽  
Vol 124 (3) ◽  
pp. 468-473 ◽  
Author(s):  
Har Prashad
Keyword(s):  
Theoretical Model ◽  
Electrical Current ◽  
Rolling Element Bearing ◽  
Rolling Element Bearings ◽  
Bearing Failure ◽  
Cause Analysis ◽  
Rolling Element ◽  
Rolling Elements ◽  
Dimensional Parameters ◽  
Element Bearing

The diagnosis and cause analysis of rolling-element bearing failure have been well studied and established in literature. Failure of bearings due to unforeseen causes were reported as: puncturing of bearings insulation; grease deterioration; grease pipe contacting the motor base frame; unshielded instrumentation cable; the bearing operating under the influence of magnetic flux, etc. These causes lead to the passage of electric current through the bearings of motors and alternators and deteriorate them in due course. But, bearing failure due to localized electrical current between track surfaces of races and rolling-elements has not been hitherto diagnosed and analyzed. This paper reports the cause of generation of localized current in presence of shaft voltage. Also, it brings out the developed theoretical model to determine the value of localized current density depending on dimensional parameters, shaft voltage, contact resistance, frequency of rotation of shaft and rolling-elements of a bearing. Furthermore, failure caused by flow of localized current has been experimentally investigated.

Spalling Size Evaluation of Rolling Element Bearing Using Acoustic Emission

2013 ◽  
Vol 569-570 ◽  
pp. 497-504 ◽  
Author(s):  
An Bo Ming ◽  
Zhao Ye Qin ◽  
Wei Zhang ◽  
Fu Lei Chu
Keyword(s):  
Acoustic Emission ◽  
Rolling Element Bearing ◽  
Rolling Element Bearings ◽  
Outer Race ◽  
Cepstrum Analysis ◽  
Rolling Element ◽  
Rolling Elements ◽  
Element Bearing ◽  
Envelope Spectrum ◽  
Size Evaluation

Spalling of the races or rolling elements is one of the most common faults in rolling element bearings. Exact estimation of the spall size is helpful to the life prediction for rolling element bearings. In this paper, the dual-impulsive phenomenon in the response of a spalled rolling element bearing is investigated experimentally, where the acoustic emission signals are utilized. A new method is proposed to estimate the spall size by extracting the envelope of harmonics of the ball passing frequency on the outer race from the squared envelope spectrum. Compared with the cepstrum analysis, the proposed procedure shows more powerful anti-noise ability in the fault size evaluation.

Experimental and numerical investigations on rolling element bearing thermal behaviour

2020 ◽  
pp. 135065012093233
Author(s):  
P Brossier ◽  
D Niel ◽  
C Changenet ◽  
F Ville ◽  
J Belmonte
Keyword(s):  
Thermal Behaviour ◽  
Volume Fraction ◽  
Operating Conditions ◽  
Rolling Element Bearing ◽  
Test Rig ◽  
Specific Test ◽  
Deep Groove ◽  
Rolling Element ◽  
Penetration Ratio ◽  
Element Bearing

In the present study, some measurements have been conducted on a dedicated test rig to investigate rolling element bearing thermal behaviour. This test rig makes possible the determination of the tested rolling element bearing power losses through the resistive torque measurement. Some thermocouples are located on fixed parts of the system (housing, rolling element bearing outer ring) and others on rotating parts (rolling element bearing inner ring and shaft) via a telemetry system. A deep groove ball bearing, whose pitch diameter is equal to 85 mm, has been tested under oil jet lubrication for different operating conditions. Measurements of the penetration ratio, defined as the proportion of oil actually entering the rolling element bearing versus the oil injected, have also been conducted. An extended thermal network of the test rig has been established to enable a closer understanding of the rolling element bearing inner thermal behaviour. Based upon the first principle of thermodynamics for transient conditions, the studied system is divided into lumped elements at uniform temperature connected by thermal resistances which account for conduction, radiation and convection. Convection within the rolling element bearing depends on the amount of oil in the oil–air mixture known as the volume fraction. At specific test conditions, the developed model found good agreements with experiences for a given oil volume fraction of 15%. This value of volume fraction leads to an adapted formula for volume fraction in the case of jet lubrication which includes the measured penetration ratio.

Application of Degree of Cyclostationarity in Rolling Element Bearing Diagnosis

2005 ◽  
Vol 293-294 ◽  
pp. 347-354 ◽  
Author(s):  
Guo Bi ◽  
Jin Chen ◽  
Jun He ◽  
Fuchang Zhou ◽  
Gui Cai Zhang
Keyword(s):  
Frequency Domain ◽  
Rolling Element Bearing ◽  
Rolling Element Bearings ◽  
Spectral Correlation ◽  
Outer Race ◽  
Cyclic Frequency ◽  
Bearing Condition Monitoring ◽  
Rolling Element ◽  
Rolling Elements ◽  
Element Bearing

Minor and random slip between rolling elements and races in rolling element bearings makes vibration signals have periodically time-varying ensemble statistics, which is known as cyclostationarity. Two second-order cyclostationary methods, the spectral correlation density (SCD) and the degree of cyclostationarity (DCS), are talked about in this paper based on a statistical model of rolling element bearings. The SCD provides redundant information in bi-frequency plane and cyclic frequency domain embodies the majority of it, which is a series of non-zero discrete cyclic frequencies completely reflecting the fault characters of rolling element bearings. The DCS has virtues of less computation and clearer representation, at the same time keeps the same characters with SCD in cyclic frequency domain. And the DCS is also proved to be resistant to the additive and multiplicative stationary noise. Simulation and experiential results from three rolling element bearing faults: outer race defect, inner race defect and rolling element defect, indicate practicability of the DCS analysis in rolling element bearing condition monitoring and fault diagnosis.

Rolling Element Bearing Non-Linearity Effects

2000 ◽  
Author(s):  
N. S. Feng ◽  
E. J. Hahn
Keyword(s):  
Equations Of Motion ◽  
Rolling Element Bearing ◽  
Radial Clearance ◽  
Rotor Systems ◽  
Bearing Life ◽  
Rolling Element ◽  
Bearing Load ◽  
Rolling Elements ◽  
Element Bearing ◽  
Negative Clearance

Non-linearity effects in rolling element bearings arise from two sources, viz. the Hertzian force deformation relationship and the presence of clearance between the rolling elements and the bearing races. Assuming that centrifugal effects may be neglected and that the presence of axial preload is appropriately reflected in a corresponding change in the radial clearance, this paper analyses a simple test rig to illustrate that non-linear phenomena such as synchronous multistable and nonsynchronous motions are possible in simple rigid and flexible rotor systems subjected to unbalance excitation. The equations of motion of the rotor bearing system were solved by transient analysis using fourth order Runge Kutta. Of particular interest is the effect of clearance, governed in practice by bearing specification and the amount of preload, on the vibration behaviour of rotors supported by ball bearings and on the bearing load. It is shown that in the presence of positive clearance, there exists an unbalance excitation range during which the bearing is momentarily not transmitting force owing to contact loss, resulting in rolling element raceway impact with potentially relatively high bearing forces; and indicating that for long bearing life, operation with positive clearance should be avoided in the presence of such unbalance loading. Once the unbalance excitation is high enough to avoid such contact loss, it is the bearings with zero or negative clearance which produce maximum bearing forces.

Rolling Element Bearing Monitoring and Diagnostics Techniques

1989 ◽  
Vol 111 (2) ◽  
pp. 251-256 ◽  
Author(s):  
R. G. Harker ◽  
J. L. Sandy
Keyword(s):  
Case Studies ◽  
Fluid Film ◽  
Rolling Element Bearing ◽  
Rolling Element Bearings ◽  
Film Type ◽  
Rolling Element ◽  
Element Bearing ◽  
Monitoring And Diagnostics ◽  
Bearing Monitoring

Rolling element bearings require distinctly different techniques for monitoring and diagnostics from those used for fluid-film type bearings. A description of these techniques and the instrumentation used to acquire the necessary data is provided for comparison. Also included are some case studies to illustrate how these techniques are applied.

scholarly journals Effects of Ultra-Clean and Centrifugal Filtration on Rolling-Element Bearing Life

1982 ◽  
Vol 104 (3) ◽  
pp. 283-291 ◽  
Author(s):  
S. H. Loewenthal ◽  
D. W. Moyer ◽  
W. M. Needelman
Keyword(s):  
Aircraft Engine ◽  
Surface Damage ◽  
Fatigue Tests ◽  
Rolling Element Bearing ◽  
Bearing Life ◽  
Deep Groove ◽  
Rolling Element ◽  
Element Bearing ◽  
High Level ◽  
Better Than

Fatigue tests were conducted on groups of 65-millimeter bore diameter deep-groove ball bearings in a MIL-L-23699 lubricant under two levels of filtration. In one test series, the oil cleanliness was maintained at an exceptionally high level (better than a class of “00” per NAS 1638) with a 3 micron absolute barrier filter. These tests were intended to determine the “upper limit” in bearing life under the strictest possible lubricant cleanliness conditions. In the tests using a centrifugal oil filter, contaminants of the type found in aircraft engine filters were injected into the filters’ supply line at 125 milligrams per bearing-hour. “Ultra-clean” lubrication produced bearing fatigue lives that were approximately twice that obtained in previous tests with contaminated oil using 3 micron absolute filtration and approximately three times that obtained with 49 micron filtration. It was also observed that the centrifugal oil filter had approximately the same effectiveness as a 30 micron absolute filter in preventing bearing surface damage.

scholarly journals Rolling Element Bearing Fault Diagnosis Based on Multiscale General Fractal Features

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Weigang Wen ◽  
Zhaoyan Fan ◽  
Donald Karg ◽  
Weidong Cheng
Keyword(s):  
Fault Diagnosis ◽  
Fractal Dimensions ◽  
Feature Space ◽  
Operating Conditions ◽  
Rolling Element Bearing ◽  
Rolling Element Bearings ◽  
Vibration Signals ◽  
Bearing Fault Diagnosis ◽  
Rolling Element ◽  
Element Bearing

Nonlinear characteristics are ubiquitous in the vibration signals produced by rolling element bearings. Fractal dimensions are effective tools to illustrate nonlinearity. This paper proposes a new approach based on Multiscale General Fractal Dimensions (MGFDs) to realize fault diagnosis of rolling element bearings, which are robust to the effects of variation in operating conditions. The vibration signals of bearing are analyzed to extract the general fractal dimensions in multiscales, which are in turn utilized to construct a feature space to identify fault pattern. Finally, bearing faults are revealed by pattern recognition. Case studies are carried out to evaluate the validity and accuracy of the approach. It is verified that this approach is effective for fault diagnosis of rolling element bearings under various operating conditions via experiment and data analysis.

Influence of Rolling Element Bearing Modeling on the Predicted Thermal Behavior of the FZG Test Rig

2016 ◽  
Vol 60 (4) ◽  
pp. 753-761 ◽  
Author(s):  
Adrien Neurouth ◽  
Christophe Changenet ◽  
Fabrice Ville ◽  
Michel Octrue
Keyword(s):  
Thermal Behavior ◽  
Rolling Element Bearing ◽  
Test Rig ◽  
Rolling Element ◽  
Element Bearing
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