Monitoring of Ball Bearing Operation under Grease Lubrication Using a New Compound Diagnostic System Detecting Vibration and Acoustic Emission

2009 ◽  
Vol 52 (6) ◽  
pp. 725-730 ◽  
Author(s):  
Takeo Yoshioka ◽  
Shigeo Shimizu
Keyword(s):  
Acoustic Emission ◽  
Ball Bearing ◽  
Diagnostic System ◽  
Grease Lubrication

Vibration and Acoustic Emission Measurements Evaluating the Separation of the Balls and Raceways With Lubricating Film in a Linear Bearing Under Grease Lubrication

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Hiroyuki Ohta ◽  
Yuko Nakajima ◽  
Soichiro Kato ◽  
Hideyuki Tajimi
Keyword(s):  
Acoustic Emission ◽  
Ball Bearing ◽  
Linear Velocity ◽  
Oil Viscosity ◽  
Grease Lubrication ◽  
Base Oil ◽  
Lubricating Film ◽  
Contact Voltage ◽  
Film Parameter ◽  
Vibratory Acceleration

This paper deals with vibration and acoustic emission (AE) measurements evaluating the separation of the balls and raceways with lubricating film in a linear-guideway–type recirculating ball bearing (linear bearing) under grease lubrication. In the experiments, three types of commercial grease, AS2, LG2, and PS2, were used. The vibratory acceleration, AE, temperature, and electric conductivity (contact voltage) in the test bearing were measured, while a carriage of the test bearing was driven at a certain linear velocity. Experimental results showed that the measured vibratory acceleration, AE, and contact voltage of the test bearing were affected by the linear velocity and the base oil viscosity of the grease. Next, the rail side film parameter ΛR and the carriage side film parameter ΛC were examined for the test bearing in operation, and it was shown that the ΛR value was lower than the ΛC value. In addition, a condition for the separation of all the balls and raceways with lubricating film was presented. Finally, it was shown that the measured root-mean-square (RMS) values of vibratory acceleration or AE can be used for evaluating the separation of all the balls and raceways with lubricating film in the test bearing.

scholarly journals Optical Analysis of Ball Bearing Starvation

1971 ◽  
Vol 93 (3) ◽  
pp. 349-361 ◽  
Author(s):  
L. D. Wedeven ◽  
D. Evans ◽  
A. Cameron
Keyword(s):  
Film Thickness ◽  
Ball Bearing ◽  
Point Contact ◽  
Experimental Measurements ◽  
Line Contact ◽  
Optical Analysis ◽  
Grease Lubrication ◽  
Theoretical Predictions ◽  
Pressure Stress ◽  
Starvation Conditions

Elastohydrodynamic oil film measurements for rolling point contact under starvation conditions are obtained using optical interferometry. The experimental measurements present a reasonably clear picture of the starvation phenomenon and are shown to agree with theoretical predictions. Starvation inhibits the generation of pressure and, therefore, reduces film thickness. It also causes the overall pressure, stress, and elastic deformation to become more Hertzian. Additional experiments using interferometry illustrate: the cavitation pattern, lubricant entrapment, grease lubrication, ball spin, and edge effects in line contact.

Effects of Grease Types on Vibration and Acoustic Emission of Defective Linear-Guideway Type Recirculating Ball Bearings

2010 ◽  
Author(s):  
Hiroyuki Ohta ◽  
Shinya Hayashi ◽  
Soichiro Kato ◽  
Yutaka Igarashi
Keyword(s):  
Acoustic Emission ◽  
Acoustic Emissions ◽  
Experimental Results ◽  
Ball Bearings ◽  
Oil Viscosity ◽  
Grease Lubrication ◽  
Base Oil ◽  
Defect Angle

In this paper, vibrations and acoustic emissions (AEs) of defective linear-guideway type recirculating ball bearings under grease lubrication were measured. The experimental results show that the vibration and AE amplitudes (the pulse amplitudes, the RMS values) of both the normal and defective bearings have a tendency to be reduced when a grease with higher base oil viscosity is used. Under the same type of grease, the RMS values of the vibrations and AE of the defective bearings increase as the defect angle increases. However, the increases of the RMS values due to increased defect angle are reduced when a grease with higher base oil viscosity is used.

Location of an acoustic emission source in a radially loaded deep groove ball-bearing

1998 ◽  
Vol 212 (1) ◽  
pp. 33-45 ◽  
Author(s):  
D Nélias ◽  
T Yoshioka
Keyword(s):  
Acoustic Emission ◽  
Ball Bearing ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Bearing ◽  
Rolling Contact ◽  
Fatigue Initiation ◽  
Deep Groove ◽  
Deep Groove Ball Bearing ◽  
Subsurface Defect

This paper describes a deep groove ball-bearing analysis which has been developed to simulate acoustic emission occurring during ball-bearing operation. The computer simulation is useful to clarify experimental research on rolling contact fatigue initiation using the acoustic emission technique. Results show the ability of the method to detect and to locate a subsurface defect, due to rolling contact fatigue, before the rolling bearing failure occurs. The subsurface defect can be accurately located within the inner ring of a deep groove ball-bearing operating under radial load.

Dynamic Analysis of Active Magnetic Bearing Rotor Dropping on Auto-eliminating Clearance Auxiliary Bearing Devices

2015 ◽  
Vol 137 (6) ◽  
Author(s):  
Chengtao Yu ◽  
Chaowu Jin ◽  
Xudong Yu ◽  
Longxiang Xu
Keyword(s):  
Dynamic Models ◽  
Ball Bearing ◽  
Experimental Studies ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Grease Lubrication ◽  
Successful Operation ◽  
Convex Shape ◽  
Auxiliary Bearing ◽  
The Impact

Auto-eliminating clearance auxiliary bearing devices (ACABD) can automatically eliminate the protective clearance between the ball bearing's outer race and the ACABD's supports, thus recenter the rotor when active magnetic bearing (AMB) system fails. This paper introduces the mechanical structure and working principles of the ACABD. When the rotor drops, numerical and experimental studies on the transient responses of the rotor and the ACABD's supports are also conducted as follows. First, we propose an equivalent clearance circle method to establish dynamic models of rotor dropping on the ACABD. Based on these models, the rotor dropping simulations are carried out to investigate the modes of lubrication and the ACABD's support shape's influences on the performance and execution time of clearance elimination. Second, various AMB rotor dropping tests are performed on our experimental setup with different ACABD supporting conditions. Indicated from the basically consistent simulation and experimental results, the correctness of the theoretical analysis and the successful operation of ACABD have been verified. Moreover, with the grease lubrication in the ball bearing and convex shape supports, the ACABD can eliminate the protective clearance within approximately 0.5 s upon the rotor drops and then sustain the rotor to operate stably around its original rotation center. Because of clearance elimination, the dramatic impact between the ball bearing and the supports is avoided and the impact forces among each part are effectively reduced. Meanwhile, the possibility of incurring full-clearance backward whirling motion is eliminated.

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