A Theoretical Model to Predict Vibration Response of Rolling Bearings to Distributed Defects Under Radial Load

1998 ◽  
Vol 120 (1) ◽  
pp. 214-220 ◽  
Author(s):  
A. Choudhury ◽  
N. Tandon
Keyword(s):  
Theoretical Model ◽  
Discrete Spectrum ◽  
Analytical Model ◽  
Relative Frequency ◽  
Vibration Response ◽  
Radial Load ◽  
Rolling Bearings ◽  
Rolling Element ◽  
Amplitude Level ◽  
Inner Race

An analytical model has been presented to predict the vibration response of rolling bearings due to distributed defects under radial load. For bearings without defect and with race defect, the model predicts a discrete spectrum with components at outer and inner race characteristic defect frequencies for the response of the respective races. The amplitude level for race defect significantly increases at the respective frequencies in comparison to the response of a bearing without defect. For a bearing with off-size rolling element, the response is at the relative frequency of cage with respect to the frequency of motion of the corresponding race.

Vibration Response of Rolling Element Bearings in a Rotor Bearing System to a Local Defect Under Radial Load

2005 ◽  
Vol 128 (2) ◽  
pp. 252-261 ◽  
Author(s):  
A. Choudhury ◽  
N. Tandon
Keyword(s):  
Theoretical Model ◽  
Vibration Response ◽  
Local Defect ◽  
Radial Load ◽  
Rolling Element ◽  
Spectral Components ◽  
Rotor Bearing ◽  
Defect Frequency ◽  
Inner Race ◽  
Bearing System

In the present investigation, a theoretical model has been developed to obtain the vibration response due to a localized defect in various bearing elements in a rotor-bearing system under radial load conditions. The rotor-bearing system has been modeled as a three degrees-of-freedom system. The model predicts significant components at the harmonics of characteristic defect frequency for a defect on the particular bearing element. In the case of a defect on the inner race or a rolling element, the model predicts sidebands about the peaks at defect frequencies, at multiples of shaft and cage frequencies, respectively. The model has also predicted some additional components at harmonics of shaft and cage frequencies due to a local defect on the inner race and a rolling element, respectively. The expressions for all these spectral components have also been derived. Typical numerical results for an NJ 204 bearing have been obtained and plotted. The amplitude of the component at defect frequency, for an outer race defect, is found to be much higher as compared to those due to inner race defect or a rolling element defect of the same size and under similar conditions of load and speed. The results of vibration measurements on roller bearings with simulated local defects have also been presented to experimentally validate the theoretical model proposed. It can be observed from the results that the spectral components predicted by the theoretical model find significant presence in the experimental spectra. Comparison of the normalized analytical values of the spectral components with their experimental values shows fair agreement for most of the cases considered. Probable area of the generated excitation pulses has been calculated and the effects of pulse area variation on the experimental results have been studied.

A Theoretical Model to Predict the Vibration Response of Rolling Bearings in a Rotor Bearing System to Distributed Defects Under Radial Load

1999 ◽  
Vol 122 (3) ◽  
pp. 609-615 ◽  
Author(s):  
N. Tandon ◽  
A. Choudhury
Keyword(s):  
Theoretical Model ◽  
Vibration Response ◽  
Radial Load ◽  
Outer Race ◽  
Rolling Element ◽  
Spectral Components ◽  
Rotor Bearing ◽  
Defect Frequency ◽  
Inner Race ◽  
Bearing System

A theoretical model to predict the vibration response of rolling element bearing in a rotor bearing system to distributed defects under radial load has been developed. The rotor bearing system has been considered as a three degrees of freedom model. The distributed defects considered are, the waviness of outer and inner races, and off size rolling element. The model predicts discrete spectrum with specific frequency components for each order of waviness. For outer race waviness, the spectrum has components at outer race defect frequency and its harmonics. In the case of inner race waviness, the waviness orders equal to number of rolling elements and its multiples give rise to spectral components at inner race defect frequency and its multiples. Other orders of waviness generate sidebands at multiples of shaft frequency about these peaks. The model predicts the amplitudes of the spectral components due to outer race waviness to be much higher as compared to those due to inner race waviness. In the case of an off-size rolling element, the model predicts discrete spectra having significant components at multiples of cage frequency. [S0742-4787(00)00603-2]

scholarly journals A theoretical model for predicting the vibration response of outer race defective ball bearing

2018 ◽  
Vol 7 (2) ◽  
pp. 289
Author(s):  
Samir Shaikh ◽  
Sham Kulkarni
Keyword(s):  
Theoretical Model ◽  
Ball Bearing ◽  
Mathematical Formulation ◽  
Vibration Response ◽  
Contact Forces ◽  
Hertzian Contact ◽  
Outer Race ◽  
Rolling Element ◽  
Rolling Elements ◽  
Extended Type

The theoretical model with 2 degree-of-freedom system is developed for predicting the vibration response and analyze frequency properties in an extended type defective ball bearing. In the mathematical formulation, the contact between the races and rolling element considered as non-linear springs. The contact forces produced during the collaboration of rolling elements are obtained by utilizing Hertzian contact deformation hypothesis. The second order nonlinear differential equation of motion is solved using a state space variable method with the help of MATLAB software and the vibration acceleration response of the defective ball bearing presented in the frequency spectrum. The effects of variation in speed and size of the defect on characteristic frequency of extended fault on the outer raceway of the ball bearing have been investigated. The theoretical results of the healthy (non defective) and defective bearing are compared with each other.

scholarly journals Fault Diagnosis of Intershaft Bearings Using Fusion Information Exergy Distance Method

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Jing Tian ◽  
Yanting Ai ◽  
Chengwei Fei ◽  
Ming Zhao ◽  
Fengling Zhang ◽  
...  
Keyword(s):  
Fault Diagnosis ◽  
Rolling Bearings ◽  
Distance Method ◽  
Ring Fault ◽  
Wavelet Space ◽  
Rolling Element ◽  
Coupling Fault ◽  
Inner Race ◽  
Ae Signals ◽  
Space Spectrum

For the fault diagnosis of intershaft bearings, the fusion information exergy distance method (FIEDM) is proposed by fusing four information exergies, such as singular spectrum exergy, power spectrum exergy, wavelet energy spectrum exergy, and wavelet space spectrum exergy, which are extracted from acoustic emission (AE) signals under multiple rotational speeds and multimeasuring points. The theory of FIEDM is investigated based on four information exergy distances under multirotational speeds. As for rolling bearings, four faults and one normal condition are simulated on a birotor test rig to collect the AE signals, in which the four faults are inner ring fault, outer ring fault, rolling element fault, and inner race-rolling element coupling fault. The faults of the intershaft bearings are analyzed and diagnosed by using the FIEDM. From the investigation, it is demonstrated that the faults of the intershaft bearings are accurately diagnosed and identified, and the FIEDM is effective for the analysis and diagnosis of intershaft bearing faults. Furthermore, the fault diagnosis precision of intershaft bearings becomes higher with increasing rotational speed.

scholarly journals Experimental Study for Vibration Behaviors of Locally Defective Deep Groove Ball Bearings under Dynamic Radial Load

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
V. N. Patel ◽  
N. Tandon ◽  
R. K. Pandey
Keyword(s):  
Good Health ◽  
Ball Bearings ◽  
Radial Load ◽  
Rolling Bearings ◽  
Revolute Joints ◽  
Deep Groove ◽  
Frequency Domains ◽  
Rolling Element ◽  
Vibration Responses ◽  
Local Defects

Rolling element bearings are used in many mechanical systems at the revolute joints for sustaining the dynamic loads. Thus, the reliable and efficient functioning of such systems critically depends on the good health of the employed rolling bearings. Hence, health monitoring of rolling bearings through their vibration responses is a vital issue. In this paper, an experimental investigation has been reported related to the vibration behaviours of healthy and locally defective deep groove ball bearings operating under dynamic radial load. The dynamic load on the test bearings has been applied using an electromechanical shaker. The vibration spectra of the healthy and defective deep groove ball bearings in time and frequency domains have been compared and discussed. Overall vibration increases in presence of local defects and dynamic radial load.

Multi-Event Excitation Force Model for Inner Race Defect in a Rolling Element Bearing

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Sidra Khanam ◽  
N. Tandon ◽  
J. K. Dutt
Keyword(s):  
Theoretical Model ◽  
Leading Edge ◽  
Rolling Element Bearing ◽  
Force Model ◽  
Impact Pulse ◽  
Sequence Of Events ◽  
Forcing Function ◽  
Rolling Element ◽  
The Impact ◽  
Inner Race

This paper presents a theoretical model for the forcing function generated on the structure as a rolling element negotiates a spall-like defect on the inner race, considered to be a moving race. The negotiation of defect has been seen as a sequence of events for the purpose of understanding the physics behind this negotiation. Such an analysis has not been attempted in the literature and thus forms the basic contribution in this work. Defects are assumed to generate two events; one at the leading edge and other at the trailing edge. The entry event at the leading edge is modeled using contact mechanics and is a function of load, speed, and curvature of defect edge whereas impact event, modeled using the principles of mechanics, is a function of load, speed, size of defect, and curvature of defect edge. The vibratory response of the nonlinear rotor bearing system subject to such excitation is simulated numerically using fourth-order Runge Kutta method and analyzed in both time and frequency domains. The modeling results provide insight into the physical mechanism which is not measured in practice and highlight the weakness of entry pulse in comparison to the impact pulse, also observed by several other researchers in their experimental tests. Defects of varying severity were simulated and tested to validate the proposed model and the acceptable correlation of amplitudes at the characteristic defect frequency provides a preliminary multi-event theoretical model. The developed model has therefore laid a theoretical platform to monitor the size of the defect on inner race which may be considered not only to identify but also to quantify the defect.

Contact characteristic and vibration mechanism of rolling element bearing in the process of fault evolution

2021 ◽  
Vol 235 (1) ◽  
pp. 19-36 ◽  
Author(s):  
Wenbing Tu ◽  
Jinwen Yang ◽  
Wennian Yu ◽  
Ya Luo
Keyword(s):  
Fault Diagnosis ◽  
Vibration Response ◽  
Rolling Element Bearing ◽  
Bearing Fault Diagnosis ◽  
Rolling Element ◽  
Vibration Mechanism ◽  
Contact Characteristic ◽  
Element Bearing ◽  
Bearing Vibration ◽  
Fault Evolution

The vibration response of rolling element bearing has a close relation with its fault. An accurate evaluation of the bearing vibration response is essential to the bearing fault diagnosis. At present, most bearing dynamics models are built based on rigid assumptions, which may not faithfully reveal the dynamic characteristics of bearing in the presence of fault. Moreover, previous similar works mainly focus on the fault with a specified size without considering the varying contact characteristics as the fault evolves. This paper developed an explicit dynamics finite element model for the bearing with three types of raceway faults considering the flexibility of each bearing component in order to accurately study the contact characteristic and vibration mechanism of defective bearings in the process of fault evolution. The developed model is validated by comparing its simulation results with both analytical and experimental results. The dynamic contact patterns between the rolling elements and the fault, the additional displacement due to the fault and the faulty characteristics within the bearing vibration signal during the fault evolution process are investigated. The analysis results from this work can provide practitioners an in-depth understanding towards the internal contact characteristics with the existence of raceway fault and theoretical basis for rolling bearing fault diagnosis.

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