scholarly journals Experimental Assessment of Influence of the Ball Bearing Raceway Curvature Ratio on the Level of Vibration

2020 ◽  
Vol 22 (4) ◽  
pp. 103-111 ◽  
Author(s):  
Pawel Zmarzly
Keyword(s):  
Experimental Studies ◽  
Rolling Bearing ◽  
Rolling Element Bearings ◽  
Test Results ◽  
Curvature Ratio ◽  
Rolling Element ◽  
Innovative System ◽  
Bearing Raceway ◽  
Bearing Rings ◽  
Car Transportation

Raceway curvature ratio is a very important parameter, because its values influence the performance characteristics of rolling-element bearings, their durability and the level of generated vibrations. However, the level of generated vibrations is one of the most important operating parameters of the rolling-element bearings. Excessive vibrations generated by rolling-element bearings affect the operation of the whole mechanism. The article presents experimental studies aimed at evaluation of influence of the inner and outer raceway curvature ratios of 6304-type rolling-element bearings on generated vibrations values. The raceway curvature ratio was determined based on results of metrological measurements. For this purpose, the radii of the inner and outer raceways as well as the diameters of the balls were measured. Design and principle of operation of an innovative system for analysis of the raceway geometry of the rolling bearing rings was presented. The vibration analysis was carried out in three frequency ranges, i.e. low (50-300 Hz), medium (300-1,800 Hz) and high (1,800-10,000 Hz). Values of measured vibrations were expressed in Anderon units. The test results showed that increase in the raceway curvature ratio causes a moderate decrease in the value of the generated vibrations. The research results presented in this article will serve as a guidance to designers and manufacturers of the rolling-element bearings on how to modify the geometry of raceways and balls to obtain bearings that generate low vibration values. That is very important in car transportation.

A NEW GEARBOX FAULT DIAGNOSIS METHOD BASED ON LUCY–RICHARDSON DECONVOLUTION

2015 ◽  
Vol 39 (3) ◽  
pp. 593-603
Author(s):  
Xinghui Zhang ◽  
Jianshe Kang ◽  
Hongzhi Teng ◽  
Jianmin Zhao
Keyword(s):  
Fault Diagnosis ◽  
Experimental Studies ◽  
Experimental Tests ◽  
Rolling Element Bearings ◽  
Envelope Analysis ◽  
Rolling Element ◽  
Negative Effect ◽  
Diagnosis Method ◽  
Good Identification ◽  
Incipient Fault Diagnosis

Gear and bearing faults are the main causes of gearbox failure. Till now, incipient fault diagnosis of these two components has been a problem and needs further research. In this context, it is found that Lucy–Richardson deconvolution (LRD) proved to be an excellent tool to enhance fault diagnosis in rolling element bearings and gears. LRD’s good identification capabilities of fault frequencies are presented which outperform envelope analysis. This is very critical for early fault diagnosis. The case studies were carried out to evaluate the effectiveness of the proposed method. The results of simulated and experimental studies show that LRD is efficient in alleviating the negative effect of noise and transmission path. The results of simulation and experimental tests demonstrated outperformance of LRD compared to classical envelope analysis for fault diagnosis in rolling element bearings and gears, especially when it is applied to the processing of signals with strong background noise.

scholarly journals Influence of raceway waviness on the level of vibration in rolling-element bearings

2017 ◽  
Vol 65 (4) ◽  
pp. 541-551 ◽  
Author(s):  
S. Adamczak ◽  
P. Zmarzły
Keyword(s):  
Ball Bearing ◽  
Correlation Coefficients ◽  
Rolling Element Bearings ◽  
Test Results ◽  
Frequency Bandwidth ◽  
Surface Waviness ◽  
Medium Frequency ◽  
Method Of Calculation ◽  
Rolling Element ◽  
Bearing Vibration

AbstractThis paper provides a quantitative analysis of how raceway waviness (RONt) in 6304-type bearings affects their vibration. The waviness of bearing races was measured at the actual points of contact between the balls and the races. The measurements were conducted in the range of 16–50 undulations per revolution (UPR). The bearing vibration was analyzed in three bandwidths of frequency: low (LB) (50 ÷ 300 Hz), medium MB (300 ÷ 1800 Hz) and high HB (1800 ÷ 10 000 Hz), as well as in the full RMS bandwidth. The paper also presents the procedure used to determine the actual points of contact between the ball and each race to specify the point of waviness measurement. The method of calculation of the contact angle for a ball bearing is also discussed. The Pearson linear correlation coefficients were determined to analyze the relationships between the waviness parameters and the level of vibration. The test results show that an increase in the surface waviness on the inner and outer raceways causes an increase in the vibration level. The influence is most visible for the medium frequency bandwidth.

Static Rolling Bearing Models in a C.A.D. Environment for the Study of Complex Mechanisms: Part II—Complete Assembly Model

1999 ◽  
Vol 121 (2) ◽  
pp. 215-223 ◽  
Author(s):  
A. Bourdon ◽  
J. F. Rigal ◽  
D. Play
Keyword(s):  
Stiffness Matrix ◽  
Load Distribution ◽  
Nonlinear Behavior ◽  
Rolling Bearing ◽  
Finite Element Models ◽  
Complex Mechanism ◽  
Assembly Model ◽  
Rolling Element ◽  
Complex Mechanical Systems ◽  
Bearing Rings

This is the second part of two companion papers, the first of which is “Static Rolling Bearing Models in a C.A.D. Environment for the Study of Complex Mechanism: Part I—Rolling Bearing Model.” A general methodology for the accurate modeling of the nonlinear behavior of ball and roller bearings is proposed. A stiffness matrix is defined both for each rolling element and for the complete rolling bearing. Thus, it can be introduced into standard finite element models of complex mechanical systems, with the aim of predicting mechanical behavior and load and strain distributions. This method is applied to two cases of helicopter and automobile gearboxes. Deformable bearing rings considerably modify contact angle and load distribution, thus the coefficient values of the stiffness matrix are different from the classical values. The paper highlights how important it is to consider an overall model of the mechanical system rather than a local one in the vicinity of the bearings.

scholarly journals Multifault Diagnosis for Rolling Element Bearings Based on Intrinsic Mode Permutation Entropy and Ensemble Optimal Extreme Learning Machine

2014 ◽  
Vol 6 ◽  
pp. 803919 ◽  
Author(s):  
Jianzhong Zhou ◽  
Jian Xiao ◽  
Han Xiao ◽  
Weibo Zhang ◽  
Wenlong Zhu ◽  
...  
Keyword(s):  
Extreme Learning Machine ◽  
Rolling Bearing ◽  
Ensemble Empirical Mode Decomposition ◽  
Permutation Entropy ◽  
Rolling Element Bearings ◽  
Bearing Fault Diagnosis ◽  
Bee Colony ◽  
Mode Decomposition ◽  
Rolling Element ◽  
Learning Machine

This paper presented a novel procedure based on the ensemble empirical mode decomposition and extreme learning machine. Firstly, EEMD was utilized to decompose the vibration signals into a number of IMFs adaptively and the permutation entropy of each IMF was calculated to generate the fault feature matrix. Secondly, a new extreme learning machine was proposed by combining ensemble extreme learning machine and the evolutionary extreme learning machine which used an artificial bee colony algorithm to optimize the input weights and hidden bias. The proposed diagnosis algorithm was applied on the three rolling bearing fault diagnosis experiments. The numerical experimental results demonstrated that the proposed method had an improved generalization performance than traditional extreme and other variants.

Methods for Assessing the Bearing Surface Durability Performance of Lubricant Formulations

2005 ◽  
Author(s):  
Harvey P. Nixon
Keyword(s):  
Rolling Element Bearings ◽  
Test Results ◽  
Bearing Surface ◽  
Evaluation Tool ◽  
Rolling Element ◽  
Performance Effects ◽  
Surface Durability ◽  
Surface Performance ◽  
Durability Performance ◽  
Lubricant Performance

Lubricant formulations and lubricant additives have been demonstrated to have a major impact on the surface durability of rolling element bearings. However, there are very few standard tests used to assess the performance aspects of lubricants as it relates to bearing surface performance. Lubricant formulations have been slanted heavily toward protecting gear concentrated contacts from galling and wear. In addition, much of the performance differentiation of lubricants has been dependent on highly accelerated standardized laboratory tests related to gears. Methods have been developed for properly evaluating a lubricant’s performance characteristics as it relates to bearings. These methods are explained and the corresponding test results are reviewed to show their effectiveness as a lubricant performance evaluation tool. The implications of these findings provide direction and suggestions for ways to minimize or avoid potential detrimental performance effects of lubricant formulations on rolling element bearings.

scholarly journals The Hybrid KICA-GDA-LSSVM Method Research on Rolling Bearing Fault Feature Extraction and Classification

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Jiyong Li ◽  
Shunming Li ◽  
Xiaohong Chen ◽  
Lili Wang
Keyword(s):  
Feature Extraction ◽  
High Speed ◽  
Wavelet Packet ◽  
Rolling Bearing ◽  
Least Square ◽  
Support Vector ◽  
Rolling Element Bearings ◽  
Kernel Independent Component Analysis ◽  
Rolling Element ◽  
Independent Features

Rolling element bearings are widely used in high-speed rotating machinery; thus proper monitoring and fault diagnosis procedure to avoid major machine failures is necessary. As feature extraction and classification based on vibration signals are important in condition monitoring technique, and superfluous features may degrade the classification performance, it is needed to extract independent features, so LSSVM (least square support vector machine) based on hybrid KICA-GDA (kernel independent component analysis-generalized discriminate analysis) is presented in this study. A new method named sensitive subband feature set design (SSFD) based on wavelet packet is also presented; using proposed variance differential spectrum method, the sensitive subbands are selected. Firstly, independent features are obtained by KICA; the feature redundancy is reduced. Secondly, feature dimension is reduced by GDA. Finally, the projected feature is classified by LSSVM. The whole paper aims to classify the feature vectors extracted from the time series and magnitude of spectral analysis and to discriminate the state of the rolling element bearings by virtue of multiclass LSSVM. Experimental results from two different fault-seeded bearing tests show good performance of the proposed method.

The Error Caused by Order Analysis for Rolling Bearing Fault Signal

2013 ◽  
Vol 819 ◽  
pp. 254-258 ◽  
Author(s):  
Wei Dong Cheng ◽  
Robert X. Gao ◽  
Jin Jiang Wang ◽  
Tian Yang Wang ◽  
Wei Gang Wen ◽  
...  
Keyword(s):  
High Speed ◽  
Vibration Signal ◽  
Rolling Bearing ◽  
Rate Of Change ◽  
Rolling Element Bearings ◽  
Factors Affecting ◽  
Order Analysis ◽  
Rolling Element ◽  
Angular Interval ◽  
The Time Domain

Defect diagnosis of rolling element bearings operating under time-varying rotational speeds entails order tracking and analysis techniques that convert a vibration signal from the time domain to the angle domain to eliminate the effect of speed variations. When a signal is resampled at a constant angular increment, the amount of data padded into each data segment will vary, depending on the rate of change in the rotational speeds. This leads to changes in the distance between the adjacent impulse peaks, and consequently, the result of order analysis. This paper presents a quantitative analysis of key factors affecting the accuracy of order analysis on rolling element bearings under variable speeds. An analytical model is established and simulated. The effects of speed variation, instantaneous speed, angular interval between impulses, and the rising time of impulse are specified. It is concluded that the results of order analysis will be smaller as the rotational speed increases, and becomes larger when the speed decreases. Furthermore, the error is larger under low speeds than high speed.

scholarly journals Grease film thickness measurement in rolling bearing contacts

2020 ◽  
pp. 135065012096127
Author(s):  
Xingnan Zhang ◽  
Romeo Glovnea
Keyword(s):  
Film Thickness ◽  
Elastohydrodynamic Lubrication ◽  
Rolling Bearing ◽  
Thickness Measurement ◽  
Lubricant Film ◽  
Rolling Element Bearings ◽  
Lubricant Film Thickness ◽  
Rolling Bearings ◽  
Rolling Element ◽  
Film Thickness Measurement

Rolling bearings are the second most used machine components. They work in what it is called elastohydrodynamic lubrication regime. The geometry of rolling element bearings makes the direct measurement of the lubricant film thickness a challenging task. Optical interferometry is widely used in laboratory conditions for studying elastohydrodynamic lubrication however it cannot be used directly in rolling element bearings thus the only suitable methods are electrical techniques. Of these, film thickness measurement based on electrical capacitance of the contacts has been used in the past by a number of authors. One of the limitations of the capacitance method, when used in rolling bearings, is that it cannot distinguish between the contacts of every rolling element and raceway on one hand and on the other between the inner and outer ring contacts. In the present study the authors used an original test rig which can measure the film thickness for only one ball and separately for the inner and outer rings of a radial ball bearing. This paper thus shows for the first-time results of the lubricant film thickness, at the inner and outer raceways, in grease lubricated rolling bearings.

Rotordynamic Evaluation of a Near-Tangential-lnjection Hybrid Bearing

1999 ◽  
Vol 121 (4) ◽  
pp. 886-891 ◽  
Author(s):  
Franck Laurant ◽  
Dara W. Childs
Keyword(s):  
Rolling Element Bearings ◽  
Test Results ◽  
Margin Of Stability ◽  
Stiffness Coefficients ◽  
Rolling Element ◽  
Radial Injection ◽  
Hybrid Bearing ◽  
San Andres ◽  
Frequency Ratios ◽  
Hydrodynamic Effects

Given the inherent DN and assembly limitations of rolling-element bearings, research is underway to develop hybrid bearings (combining hydrostatic and hydrodynamic effects) for their replacement. Hybrid bearings develop cross-coupled stiffness coefficients due to fluid rotation, leading to predictions of onset speeds of instability and potential limitations in their range of application. Injecting fluid into a bearing recess against rotation, versus the customary radial injection, can reduce the circumferential flow and the cross-coupled-stiffness coefficients, and increase the margin of stability. Test results are presented here for a hybrid bearing with against-rotation injection. The bearing has a 76.4 mm diameter with LID = 1, and CrIR = 0.001. Data are presented for 55°C water at three speeds out to 25000 rpm and three pressures out to 7.0 MPa. Compared to a radial-injection hybrid bearing, experiments show injection against rotation enhances stability, yielding reductions of cross-coupled stiffness coefficients and whirl frequency ratios. However, increased flow rate and a drop of effective stiffness with increasing speed adversely affect the bearing performance. The prediction code developed by San Andres (1995) includes angled-orifice injection. The code correctly predicts trends, but at low speed, measured cross-coupled stiffness coefficients are positive, versus a prediction of larger negative values.

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