Vibration Monitoring and Damage Quantification of Ball Bearings for Household Appliances

2005 ◽  
Author(s):  
F. K. Choy ◽  
D. Konrad ◽  
E. Labus ◽  
R. Wu
Keyword(s):  
Vibration Monitoring ◽  
Ball Bearings ◽  
Household Appliances ◽  
Rejection Level ◽  
Bearing Assembly ◽  
Bearing Vibration ◽  
Vibration Signatures ◽  
The Relationship ◽  
High Rejection ◽  
Vibration Noise

The main objective of this paper is to determine the relationship between bearing vibration/noise and the amount of flaws existed in a ball bearing assembly. In this study, 30 “good” and 30 “bad” typical ball bearings used for transmissions in household appliances are used for experimental vibration testing and measurements of flaws. While the “good” bearings are obtained form the lot of bearings tested for acceptable noisy level and the “bad” bearings are obtained from the lot with high rejection level. Although some irregularities are found in the ball elements, but most of the flaws are found in the outer races of the “bad” bearings. The levels of the flaws are measured using micrometers and vibration levels of the bearings are obtained from the accelerometers attached to the bearing supports at the bearing test rig. Time domain, frequency domain, and chaotic vibration signatures for the bearing are examined to correlate with the levels of flaws in the outer races of the bearings. The results from the FFT spectra show that the average vibration amplitude of the “bad” bearing is about 5 times higher than those of the “good” bearings.

The importance of bearing stiffness and load when estimating the size of a defect in a rolling element bearing

2018 ◽  
Vol 18 (5-6) ◽  
pp. 1527-1542 ◽  
Author(s):  
Francesco Larizza ◽  
Alireza Moazen-Ahmadi ◽  
Carl Q Howard ◽  
Steven Grainger
Keyword(s):  
Large Data ◽  
Rolling Element Bearing ◽  
Static Stiffness ◽  
Data Set ◽  
Rolling Element ◽  
Bearing Stiffness ◽  
Bearing Assembly ◽  
Element Bearing ◽  
Vibration Signatures ◽  
Force Displacement

The change in the static stiffness of a bearing assembly is an important discriminator when determining the size of a defect in a rolling element bearing. In this article, the force–displacement relationships for defective bearings under various static radial loadings at various cage angular positions are analytically estimated and experimentally measured and analyzed. The study shows that the applied load has a significant effect on the static stiffness variations in defective rolling element bearings. The experimental measurements of the effect of the defect size on the varying stiffness of the bearing assembly, which has not been shown previously, provides valuable knowledge for developing methods to distinguish between defective bearings with defects that are smaller or larger than one angular ball spacing. The methods and results presented here contribute to the wider experimental investigation of the effects of loadings on the varying static stiffness of defective bearings and its effects on the measured vibration signatures. A large data set was obtained and has been made publicly available.

Vibration Signatures of Temperature Trended Bearings in Field and Laboratory Testing

2009 ◽  
Author(s):  
Constantine M. Tarawneh ◽  
Javier A. Kypuros ◽  
Arturo A. Fuentes ◽  
Brent M. Wilson ◽  
Bertha A. Gonzalez ◽  
...  
Keyword(s):  
Friction And Wear ◽  
Vibration Signal ◽  
Laboratory Research ◽  
University Of Texas ◽  
Union Pacific ◽  
Bearing Vibration ◽  
Pan American ◽  
Testing Field ◽  
The University ◽  
Vibration Signatures

Over the past two years, a series of papers have been published concerning bearing temperature trending and a mechanism to explain this troubling phenomenon. In September of 2008, a collaborative field test between The Union Pacific Railroad (UP), Amsted Rail, Rail Sciences Inc. (RSI), and The University of Texas-Pan American (UTPA) was conducted to corroborate the findings of laboratory research and testing. Field and laboratory results confirm that temperature trended bearings exhibit vibration signals that can be distinguished from healthy bearings. Distinct primary frequencies and overtones associated with the axle, cone, cage, and rollers can be readily identified within a bearing vibration signal. In a previous paper, it was demonstrated that a trended bearing exhibits vibrations of higher magnitude. However, all characteristic frequencies appear in both healthy and trended bearings, but those that dominate, i.e., have higher magnitude, are distinct for trended bearings when compared to healthy bearings. The latter can be repeatedly demonstrated in both field and laboratory experiments. Moreover, the current work identifies and distinguishes between the primary bearing frequencies and those linked to roller misalignment, which is known to increase friction and wear, and consequently raise the bearing temperature.

Signature Analysis of Roller Bearing Vibrations: Lubrication Effects

1992 ◽  
Vol 206 (3) ◽  
pp. 193-202 ◽  
Author(s):  
Y-T Su ◽  
Y-T Sheen ◽  
M-H Lin
Keyword(s):  
Roller Bearing ◽  
Vibration Energy ◽  
Running Speed ◽  
Oil Film ◽  
Spacing Distribution ◽  
Surface Irregularities ◽  
Vibration Signature ◽  
Bearing Assembly ◽  
Bearing Vibration ◽  
Lubricant Viscosity

This study investigates the vibration signature of roller bearings, induced by the surface irregularities of components, under various lubricating conditions. The bearing vibration is modelled as the output of the bearing assembly which is subjected to the excitations of surface irregularities through the oil-film. The oil-film acts as a spring between the roller and race. The stiffness of oil-film under different lubricating conditions is studied from the empirical equation of minimum oil-film thickness. It is shown that the vibration spectra of a normal roller bearing may have a pattern of equal frequency spacing distribution (EFSD) whose frequency information is similar to that of a damaged bearing. Under large loading and low running speed, the vibration energy is low if the lubricant viscosity is high. On the other hand, at high running speed, the vibration energy is high with high lubricant viscosity.

Using Triaxial Accelerometer Data for Vibration Monitoring of Helicopter Gearboxes

2001 ◽  
Author(s):  
Irem Y. Tumer ◽  
Edward M. Huff
Keyword(s):  
Vibration Monitoring ◽  
Monitoring Systems ◽  
Accelerometer Data ◽  
Frequency Content ◽  
Additional Information ◽  
Vibration Data ◽  
Statistical Variation ◽  
Novel Method ◽  
Monitoring And Diagnostics ◽  
Vibration Signatures

Abstract Typical vibration monitoring systems for helicopter gearboxes rely on single-axis accelerometer data. This paper investigates whether triaxial accelerometers can provide crucial flight regime information for helicopter gearbox monitoring systems. The frequency content of the three different directions is compared and analyzed using time-synchronously averaged vibration data. The triaxial data are decorrelated using a mathematical transformation, and compared to the original axes to determine their optimality. The benefits of using triaxial data for vibration monitoring and diagnostics are explored by analyzing the changes in the direction of the principal axis of vibration formed using all three axes of vibration. The statistical variation introduced due to the experimental variables is further analyzed using an Analysis of Variance approach to determine the effect of each variable on the overall signature. The results indicate that triaxial accelerometers can provide additional information about the frequency content of helicopter gearbox vibrations, providing researchers and industry with a novel method of capturing and monitoring changes in the baseline vibration signatures.

Rejection Sensitivity, Jealousy, and the Relationship to Interpersonal Aggression

2016 ◽  
Vol 33 (13) ◽  
pp. 2118-2129 ◽  
Author(s):  
Anna M. Murphy ◽  
Gemma Russell
Keyword(s):  
Interpersonal Relationships ◽  
Rejection Sensitivity ◽  
Future Research ◽  
Mediation Model ◽  
Prevention Education ◽  
Interpersonal Aggression ◽  
Study Results ◽  
Aggressive Reactions ◽  
The Relationship ◽  
High Rejection

The development and maintenance of interpersonal relationships lead individuals to risk rejection in the pursuit of acceptance. Some individuals are predisposed to experience a hypersensitivity to rejection that is hypothesized to be related to jealous and aggressive reactions within interpersonal relationships. The current study used convenience sampling to recruit 247 young adults to evaluate the relationship between rejection sensitivity, jealousy, and aggression. A mediation model was used to test three hypotheses: Higher scores of rejection sensitivity would be positively correlated to higher scores of aggression (Hypothesis 1); higher scores of rejection sensitivity would be positively correlated to higher scores of jealousy (Hypothesis 2); jealousy would mediate the relationship between rejection sensitivity and aggression (Hypothesis 3). Study results suggest a tendency for individuals with high rejection sensitivity to experience higher levels of jealousy, and subsequently have a greater propensity for aggression, than individuals with low rejection sensitivity. Future research that substantiates a link between hypersensitivity to rejection, jealousy, and aggression may provide an avenue for prevention, education, or intervention in reducing aggression within interpersonal relationships.

scholarly journals Experimental Investigation of Clearance Influences on Cage Motion and Wear in Ball Bearings

2021 ◽  
Vol 11 (24) ◽  
pp. 11848
Author(s):  
Baogang Wen ◽  
Meiling Wang ◽  
Xu Zhang ◽  
Jingyu Zhai ◽  
Wei Sun
Keyword(s):  
Experimental Investigation ◽  
Vital Role ◽  
Operating Conditions ◽  
Ball Bearings ◽  
Test Rig ◽  
The Stability ◽  
The Relationship ◽  
Ring Frequency

Clearances of cages in ball bearings, including pocket and guiding clearances, play a vital role in the stability and reliability of bearings. In this paper, experiments on the cage motion and wear were carried out to investigate the influence of clearances in ball bearings. Firstly, the cages with a series of pocket and guiding clearances were specially designed and tested for prescribed operating conditions on a bearing test rig in which the cage motions were measured, and corresponding wear was also observed. Then, the normalized trajectory, waveform, and spectra of cage motion were constructed and compared to illustrate the effects of clearances on the cage motion and then to establish the relationship between cage motion and wear. Results reveal that the cage motion and wear are both significantly affected by its clearances. The increment of cage guiding clearance makes the whirl trajectories of the cage regular and the motion frequency of cage motion significantly change. However, the increment of cage pocket clearance make the whirl trajectories change from well-defined patterns to complicated ones, and the frequency of cage motion apparently changes. Additionally, the bearing wear is closely related to the cage motion. If the inner ring frequency is of domination for the cage motion, the cage guiding surface will wear seriously. While cage motion is dominated by two times cage frequency in spectrum domain, the cage pocket will wear more seriously.

Sign in / Sign up

Export Citation Format

Share Document