Analysis of Roller/Ball Bearing Vibrations

1979 ◽  
Vol 101 (1) ◽  
pp. 118-125 ◽  
Author(s):  
S. Braun ◽  
B. Datner

Described is a vibration based diagnostic method aimed at detecting localized defects developing in roller/ball bearings. The signature is decomposed into generalized periodic functions and a search strategy for the various components developed and implemented. The method is shown to be applicable for cases where spectral analysis fails to give results.

1987 ◽  
Vol 109 (1) ◽  
pp. 60-68 ◽  
Author(s):  
H. Kanai ◽  
M. Abe ◽  
K. Kido

This paper describes a vibration-based diagnostic method by estimating the surface roughness on the rotating ring or balls in ball bearings. The surface roughness has been measured by a stylus that directly traverses the surface of the ring or balls obtained by taking apart the ball bearing. We developed a new method to estimate accurately the surface roughness by analyzing the short-length vibration signal that is excited when balls encounter flaws on the rotating ring or when races encounter flaws on the balls in a ball bearing. Our experimental results confirm that the roughness estimated by the proposed method agrees with that measured directly by using a stylus even in the case of crack μm wide. We applied this new method to the diagnosis of surface roughness in small-sized ball bearings and inferior samples were detected with a 95.3 percent accuracy rate.


Author(s):  
O Cakmak ◽  
K Y Sanliturk

A ball bearing comprising rolling elements, inner and outer rings, and a cage structure can be described as a multi-body system (MBS). In order to predict the dynamic behaviour and resonance characteristics of a rotor–ball bearing system, it can be modelled and analysed as a MBS with flexible and rigid parts. In this study, a ball bearing is modelled with MBS approach using MSC ADAMS commercial software. The Hertzian theory is used for modelling the contact dynamics between the balls and the rings. The ball bearing model is then assembled with the rotor model which comprised a shaft and a disc positioned at the free end of the shaft. The ball bearing model is used with both flexible and rigid shaft assumptions in order to highlight the differences between the two cases. For the flexible shaft case, the MBS model also included a finite element model of the shaft. As expected, it is necessary to include the flexibility of the shaft in the model in order to to predict the changes in the modal characteristics of the system as a function of the rotor speed. Furthermore, including the gyroscopic effects leads to observe the forward and backward travelling modes with different natural frequencies. The effects of the bearing diametral clearance and localized defects on the inner and outer rings are modelled and analysed using the model developed. Also, the effects of the rotor unbalance on the vibration level of the whole system are examined. A test rig – consisting of two ball bearings, a shaft, and a disc – is also designed and developed so as to validate the theoretical model using experimental data. Order tracking and modal analyses are carried out and Campbell diagrams are obtained. Finally, the theoretical and the experimental results are compared and a refined MBS model is obtained for further analyses.


Author(s):  
F. Bakhtiary-Nejad ◽  
A. H. Nayeb ◽  
S. E. Yeganeh

In this paper, existence of localized defects in a ball bearing has been diagnosed using vibration analysis. First, different kinds of faults which occur in ball bearings have been investigated. Then an analytical model has been proposed for determining the damaged ball bearing vibrations due to a localized defect. Also various methods of fault detection have been evaluated. Next, in order to examine the ball bearings, a testing set-up has been designed and constructed. Then by preparing a computer program, which calculates defect frequencies, some ball bearings have been tested. The test results were originally derived in time-domain. Then by using vibration analysis of healthy and damaged ball bearings in frequency-domain, a fault detection method for ball bearings has been proposed.


2019 ◽  
Vol 12 (3) ◽  
pp. 248-261
Author(s):  
Baomin Wang ◽  
Xiao Chang

Background: Angular contact ball bearing is an important component of many high-speed rotating mechanical systems. Oil-air lubrication makes it possible for angular contact ball bearing to operate at high speed. So the lubrication state of angular contact ball bearing directly affects the performance of the mechanical systems. However, as bearing rotation speed increases, the temperature rise is still the dominant limiting factor for improving the performance and service life of angular contact ball bearings. Therefore, it is very necessary to predict the temperature rise of angular contact ball bearings lubricated with oil-air. Objective: The purpose of this study is to provide an overview of temperature calculation of bearing from many studies and patents, and propose a new prediction method for temperature rise of angular contact ball bearing. Methods: Based on the artificial neural network and genetic algorithm, a new prediction methodology for bearings temperature rise was proposed which capitalizes on the notion that the temperature rise of oil-air lubricated angular contact ball bearing is generally coupling. The influence factors of temperature rise in high-speed angular contact ball bearings were analyzed through grey relational analysis, and the key influence factors are determined. Combined with Genetic Algorithm (GA), the Artificial Neural Network (ANN) model based on these key influence factors was built up, two groups of experimental data were used to train and validate the ANN model. Results: Compared with the ANN model, the ANN-GA model has shorter training time, higher accuracy and better stability, the output of ANN-GA model shows a good agreement with the experimental data, above 92% of bearing temperature rise under varying conditions can be predicted using the ANNGA model. Conclusion: A new method was proposed to predict the temperature rise of oil-air lubricated angular contact ball bearings based on the artificial neural network and genetic algorithm. The results show that the prediction model has good accuracy, stability and robustness.


2017 ◽  
Vol 866 ◽  
pp. 375-378
Author(s):  
Sathitbunanan Sumate ◽  
Wirote Ritthong

The ball bearings are the rotating components which are widely spread to moving parts for all machinery operation in general industry. This paper presents the ball bearing resistance tool which has a proper size and can handle the maximum load of 300 kg by using an electric power. The ball bearing resistance tool was used to test the bearings No. 6011 cm. The series of tests was performed in the ball bearings lubricated; engine oil SAE 10W/40, auto transmission fluid Dexron, and hydraulic oil. The rotational speeds for testing were vary; 500, 600 and 700 rpm respectively. At each speed, there were various weight; 50, 70, 90,110,130,150, and 170 kg respectively. The results show that the hydraulic oil generated the smallest coefficients of friction and energy efficiency for ball bearing operation.


1976 ◽  
Vol 98 (3) ◽  
pp. 463-469 ◽  
Author(s):  
C. R. Gentle ◽  
R. J. Boness

This paper describes the development of a computer program used to analyze completely the motion of a ball in a high-speed, thrust-loaded ball bearing. Particular emphasis is paid to the role of the lubricant in governing the forces and moments acting on each ball. Expressions for these forces due to the rolling and sliding of the ball are derived in the light of the latest fluid models, and estimates are also made of the cage forces applicable in this specific situation. It is found that only when lubricant viscoelastic behavior is considered do the theoretical predictions agree with existing experimental evidence.


2018 ◽  
Vol 141 (3) ◽  
Author(s):  
Shengye Lin ◽  
Shuyun Jiang

This paper studies the stiffness characteristics of preloaded duplex angular contact ball bearings. First, a five degrees-of-freedom (5DOF) quasi-static model of the preloaded duplex angular contact ball bearing is established based on the Jones bearing model. Three bearing configurations (face-to-face, back-to-back, and tandem arrangements) and two preload mechanisms (constant pressure preload and fixed position preload) are included in the proposed model. Subsequently, the five-dimensional stiffness matrix of the preloaded duplex angular contact ball bearing is derived analytically. Then, an experimental setup is developed to measure the radial stiffness and the angular stiffness of duplex angular contact ball bearings. The simulated results match well with those from experiments, which prove the validity of the proposed model. Finally, the effects of bearing configuration, preload mechanism, and unloaded contact angle on the angular stiffness and the cross-coupling are studied systematically.


Author(s):  
Michael Flouros

Trends in aircraft engine design cause increased mechanical stress requirements for rolling bearings. Consequently high amounts of heat are rejected which results in high oil scavenge temperatures. The direction of oil flow in the bearing can considerably affect the heat transported by the oil. An RB199 turbofan bearing and its associated chamber were modified to carry out the survey. The test bearing was a 124mm PCD ball bearing. The bearing has a split inner-ring employing under-race lubrication by two individual jets. The total oil flow could be devided to any ratio through the jets. This had an impact on the oil scavenge temperatures and the scavenge flows on both sides of the bearing. Significant reduction in the ‘heat to oil’ was achieved when oil was fed at certain proportions (ratio). This work is part of the European Research programme Brite Euram ATOS (Advanced Transmission and Oil Systems).


2018 ◽  
Vol 5 (4) ◽  
pp. 427-434 ◽  
Author(s):  
M.Y. Toumi ◽  
S. Murer ◽  
F. Bogard ◽  
F. Bolaers

Abstract Bearings are essential elements in the design of rotating machines. In an industrial context, bearing failure can have costly consequences. This paper presents a study of the rolling contact fatigue damage applied to thrust ball bearings. It consists in building a dynamic three-dimensional numerical model of the cyclic shift of a ball on an indented rolling surface, using finite element analysis (FEA). Assessment of the evolution in size of a surface spall as a function of loading cycles is also performed using FEM coupled with fatigue laws. Results are in good agreement with laboratory tests carried out under the same conditions using a fatigue test cell dedicated to ball bearings. This study may improve knowledge about estimating the lifetime of rolling components after onset of a spall using FEA and accounting for structural damage state. Highlights The experimental apparatus and damaged thrust ball bearing are described. We model a portion of the thrust ball bearing featuring a spherical indent. Numerical results in terms of stress field are compared to analytical results from the literature. A fatigue software is used to assess the evolution of spalling size. Good agreement is obtained between experimental test campaigns at different loads and FEA results.


1952 ◽  
Vol 56 (504) ◽  
pp. 885-908 ◽  
Author(s):  
M. S. Frenkel

In this paper it is shown how, in an angular contact ball bearing, the motion of a ball depends on the dimensions, loading and speed of the bearing. In general, ball motion in an angular contact bearing differs from the simple motion usually visualised by including oscillatory occurrences, shown here analytically, graphically and visually. These oscillatory occurrences are shown to lead to premature fatigue of the bearing metal, as a function of the speed of rotation, thereby imposing the present limitations on maximum speed and “ life.”It is further shown that only when the dimensions of an angular contact ball bearing are related in a certain way, a motion is produced in which the oscillatory phenomena are eliminated. These relations are given as functions of loading and speed in a system of equations and limiting conditions (hereafter referred to as “ Relations of the Dimensions ”).


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