scholarly journals Studies on vibration and sound of defective rolling bearings (5th report, Diagnosing method of defects i a ball bearing equipped with machine)

1986 ◽  
Vol 52 (473) ◽  
pp. 32-39
Author(s):  
Teruo IGARASHI ◽  
Kiyokazu TAJIMA
Keyword(s):  
Ball Bearing ◽  
Rolling Bearings

Oil Pumping in High Speed and High Loaded Ball Bearings

2004 ◽  
Author(s):  
Michael Flouros
Keyword(s):  
High Speed ◽  
Ball Bearing ◽  
Research Programme ◽  
Aircraft Engine ◽  
Ball Bearings ◽  
European Research ◽  
Rolling Bearings ◽  
Engine Design ◽  
Oil Flow ◽  
Total Oil

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).

Effects of Some Hydraulic Fluid Lubricants on the Fatigue Lives of Rolling Bearings

1968 ◽  
Vol 183 (16) ◽  
pp. 21-27 ◽  
Author(s):  
R. A. Hobbs ◽  
G. W. Mullett
Keyword(s):  
Ball Bearing ◽  
Fatigue Testing ◽  
Mineral Oil ◽  
Equipment Design ◽  
Hydraulic Fluid ◽  
Oil Lubrication ◽  
Rolling Bearings ◽  
Test Conditions ◽  
Hydraulic Equipment

Hydraulic equipment operating in potentially explosive or inflammable atmospheres (e.g. pumps in mines) has to use special fluids which are fire-resistant. Frequently the equipment design is such that the same fluid is used to lubricate rolling bearings. It is already known that some fluids, particularly those containing water, cause a serious reduction in the fatigue lives of the bearings. This paper describes a ball bearing rig and the test conditions under which several fire-resistant fluids were evaluated. It compares the fatigue lives obtained with the lives obtained when using mineral oil lubrication. Factors by which bearing capacities should be reduced when using these fluids are suggested. The fatigue testing of batches of bearings is time-consuming and the fluids are continually undergoing development. There is thus some difficulty in keeping up-to-date. However, the capacity factors given are indicative of the magnitudes of the effects that fire-resistant fluids can have on bearing lives.

Hysteretic Resonances and Intermittency Chaos in Ball Bearings

2018 ◽  
Author(s):  
Zhiyong Zhang ◽  
Xiaoting Rui ◽  
Yushu Chen ◽  
Wenkai Dong ◽  
Lei Li
Keyword(s):  
Ball Bearing ◽  
Harmonic Balance Method ◽  
Rolling Bearing ◽  
Hertzian Contact ◽  
Ball Bearings ◽  
Rolling Bearings ◽  
Rotor Systems ◽  
Revolute Joints ◽  
Rolling Elements ◽  
Varying Compliance

Ball bearings are essential parts of mechanical systems to support the rotors or constitute the revolute joints. The time-varying compliance (VC), bearing clearance and the Hertzian contact between the rolling elements and raceways are three fundamental nonlinear factors in a ball bearing, hence the ball bearing can be considered as a nonlinear system. The hysteresis and jumps induced by the nonlinearities of rolling bearings are typical phenomena of nonlinear vibrations in the rolling bearing-rotor systems. And the corresponding hysteretic impacts have direct effects on the cleavage derivative and fatigue life of the system components. Therefore, the behaviors of hysteresis and jumps are given full attentions and continued studies in the theoretical and engineering fields. Besides, many researchers have done a lot of calculations to depict the various characteristics of bifurcations and chaos in the rolling bearings and their rotor systems, but few researches have been addressed on the inherent mechanism of the typical intermittency vibrations in rolling bearings. With the aid of the HB-AFT (the harmonic balance method and the alternating frequency/time domain technique) method and Floquet theory, this paper will investigate deeply the resonant hysteresis and intermittency chaos in ball bearings.

Porous Retainers for Rolling Bearings

1981 ◽  
Vol 23 (6) ◽  
pp. 263-271
Author(s):  
R. Gohar ◽  
H. So
Keyword(s):  
Ball Bearing ◽  
Porous Matrix ◽  
Critical Value ◽  
Eccentricity Ratio ◽  
Rolling Bearings ◽  
High Coefficient ◽  
Lubrication Regime ◽  
Permeability Parameter ◽  
Mixed Film ◽  
Film Lubrication

A theoretical analysis is made for the lubrication of ball bearing retainers made of porous material. The results show that at low Sommerfeld reciprocals, the eccentricity ratio tends to unity with a high coefficient of friction. At a certain critical value of the reciprocal, a minimum friction occurs, thereafter followed by hydrodynamic operation. The critical value depends on the permeability parameter of the porous matrix and increases with its porosity. Experiments suggest that at low Sommerfeld reciprocals or with the oil supply coming only from the retainer pores, mixed film lubrication occurs, friction being less than that obtained theoretically. Such a lubrication regime would still allow sufficient oil to be carried by the balls to the races for their lubrication.

Ferrofluid lubrication for ball bearings to avoid starvation

2020 ◽  
Vol 72 (10) ◽  
pp. 1227-1231
Author(s):  
Mancheng Xu ◽  
Guanghu Jin ◽  
Qingwen Dai ◽  
Wei Huang ◽  
Xiaolei Wang
Keyword(s):  
Magnetic Field ◽  
Service Life ◽  
Peer Review ◽  
Design Methodology ◽  
Ball Bearing ◽  
Magnetic Circuit ◽  
Ball Bearings ◽  
Rolling Bearings ◽  
Content Type ◽  
Circuit Structure

Purpose This paper aims to prevent oil starvation and improve the service life of the rolling bearings. Design/methodology/approach A thrust ball bearing with magnetic circuit structure is proposed for ferrofluid lubrication. With the aid of magnetic field, ferrofluid can be maintained in the contact area of rolling bodies to delay lubricant loss. Experiments are performed to ensure the validity of the designed bearing. Findings Compared with conventional lubricant, service life of the ferrofluid lubricated bearing can be prolonged under magnetic field. In addition, with a proper magnetic field distribution, lubricant starvation may be limited under the conditions of present experiments. Originality/value This work provides a method to control the starved lubrication of rolling bearings with restricted lubricant supply. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-04-2020-0132/

scholarly journals Suppression of Complex Hysteretic Resonances in Varying Compliance Vibration of a Ball Bearing

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Zhiyong Zhang ◽  
Thomas Sattel ◽  
Aditya Suryadi Tan ◽  
Xiaoting Rui ◽  
Shaopu Yang ◽  
...  
Keyword(s):  
Ball Bearing ◽  
Hertzian Contact ◽  
Rolling Bearings ◽  
Dynamical Mechanism ◽  
Nonlinear Characteristics ◽  
Bearing Clearance ◽  
Rolling Elements ◽  
Bearing Stiffness ◽  
Hysteretic Characteristics ◽  
The Stability

It is traditionally considered that, due to the Hertzian contact force-deformation relationship, the stiffness of rolling bearings has stiffening characteristics, and gradually researchers find that the supporting characteristics of the system may stiffen, soften, and even coexist from them. The resonant hysteresis affects the stability and safety of the system, and its jumping effect can make an impact on the system. However, the ball bearing contains many nonlinearities such as the Hertzian contact between the rolling elements and raceways, bearing clearance, and time-varying compliances (VC), leading great difficulties to clarify the dynamical mechanism of resonant hysteresis of the system. With the aid of the harmonic balance and alternating frequency/time domain (HB-AFT) method and Floquet theory, this paper will investigate the hysteretic characteristics of the Hertzian contact resonances of a ball bearing system under VC excitations. Moreover, the linearized dynamic bearing stiffness of the system will be presented for assessing the locations of VC resonances, and the nonlinear characteristics of bearing stiffness will also be discussed in depth. Our analysis indicates that the system possesses many types of VC resonances such as the primary, internal, superharmonic, and even combination resonances, and the evolutions of these resonances are presented. Finally, the suppression of resonances and hysteresis of the system will be proposed by adjusting the bearing clearance.

scholarly journals Analysis the amount of lubrication and roughness of raceways on dynamic behavior on the ball bearing

2019 ◽  
Vol 290 ◽  
pp. 01005
Author(s):  
Ivan Knežević ◽  
Aleksandar Živković ◽  
Mirjana Bojanić Šejat ◽  
Milan Rackov ◽  
Milan Zeljković ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Dynamic Behavior ◽  
Ball Bearing ◽  
Operating Principle ◽  
Periodic Change ◽  
Vibration Level ◽  
Rolling Bearings ◽  
Number Of Factors

The operating principle of rolling bearings generates vibrations that come from the periodic change in the stiffness of the bearing. The vibration level of the bearing depends on a large number of factors such as waviness, surface roughness of the raceways, deviation of the raceway radius, exploitation conditions, amount of lubrication in the bearing and other. This paper presents the influence of the roughness of the raceways and the amount of lubrication on the level of vibrations of the ball bearing, designation 6006. The determination of the influence of these parameters was done experimentally. The experiment was performed according conditions prescribed by ISO 15242-2, and the analysis of the measured signals was performed according to the guidelines given by the standard ISO 15242-1.

Fault Recognition Method of Rolling Bearings Based on Volterra Series and HMM

2009 ◽  
Vol 413-414 ◽  
pp. 561-567
Author(s):  
Jing Jiang ◽  
Zhi Nong Li
Keyword(s):  
Mechanical System ◽  
Ball Bearing ◽  
Volterra Series ◽  
Subspace Method ◽  
Recognition Method ◽  
Experiment Data ◽  
Rolling Bearings ◽  
Vibration Signals ◽  
Feature Vectors ◽  
Fault Recognition

A new bearing fault recognition method based on volterra series and HMM is proposed. In the proposed method, first the feature vectors are extracted from amplitude demodulated signals obtained from normal, ball, inner and outer faulty bearings. The feature vectors are based on the volterra series of the vibration signals, which is obtained by the subspace method. Then these feature vectors are input to each fault’s HMM to be recognized. The result of experiment shows that the proposed method is very effective. The proposed method is tested with the experiment data sampled from drive end ball bearing of an induction motor driven mechanical system.

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