Effects of Grease Characteristics on Sound and Vibration of a Linear-Guideway Type Recirculating Ball Bearing

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Hiroyuki Ohta ◽  
Tatsuya Tsuruoka ◽  
Yukitoshi Fujinami ◽  
Soichiro Kato
Keyword(s):  
Atmospheric Pressure ◽  
Sound Pressure ◽  
Ball Bearing ◽  
Viscosity Coefficient ◽  
Linear Velocity ◽  
Base Oil ◽  
First Sound ◽  
Absolute Viscosity ◽  
Vibratory Acceleration ◽  
Sound Vibration

This paper deals with the effects of grease characteristics on sound and vibration of a linear-guideway type ball bearing. First, sound, vibration, and temperature of a linear-guideway type ball bearing were measured by changing 16 types of greases. Next, in order to explain the effects of grease characteristics (absolute viscosity η0 of the base oil in the grease at atmospheric pressure, pressure–viscosity coefficient ξ of the base oil, and penetration P of grease) and linear velocity V on the sound pressure p and vibratory acceleration a of the linear bearing, dimensional analyses were carried out. The dimensional analyses derived dimensionless products Pp/(η0V) and η0ξV/P for the sound, and dimensionless products Pa/V2 and η0ξV/P for the vibration. The plot of the measured data using dimensionless products showed that both sound pressure p and vibratory acceleration a (under a certain linear velocity) decreased as the absolute viscosity η0 of the base oil in the grease at atmospheric pressure or the pressure–viscosity coefficient ξ increased. Whereas the sound pressure p decreased as the penetration P decreased, the vibratory acceleration a decreased as P increased.

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.

Using Ceramic Balls to Reduce Noise in a Linear Guideway Type Recirculating Linear Ball Bearing

2003 ◽  
Vol 125 (3) ◽  
pp. 480-486 ◽  
Author(s):  
Hiroyuki Ohta ◽  
Takumi Nakagawa
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Ball Bearing ◽  
Pressure Level ◽  
Linear Velocity ◽  
Sound Frequency ◽  
Experimental Results ◽  
New Method ◽  
Sound Pressure Levels ◽  
Steel Balls

A new method of reducing the noise of the linear guideway type recirculating linear ball bearing (linear bearing) was studied. In the experiments, the overall sound pressure levels of linear bearings with steel balls or ceramic Si3N4 balls were measured, and sound frequency analyses were carried out. Moreover, based on the assumption that the main cause of the noise may be the collision between the ball and the carriage, the overall sound pressure levels of the linear bearings were analyzed combining the Hertzian theory and the results of previous studies on collision sound. From the results of experiments and analyses, the conclusions were obtained as follows: (1) The overall sound pressure level of the linear bearing with steel balls can be reduced by about 4.5 dB by using Si3N4 balls having the same diameter; (2) The overall sound pressure levels of linear bearings with steel balls or ceramic Si3N4 balls were both increased by about 9.8 dB as the linear velocity increased an octave; and (3) The analytical results, based on the assumption that the main cause of the noise emitted from the linear bearings is the collision between the ball and the carriage, match the experimental results well.

Sound of Linear Guideway Type Recirculating Linear Ball Bearings

1999 ◽  
Vol 121 (4) ◽  
pp. 678-685 ◽  
Author(s):  
Hiroyuki Ohta
Keyword(s):  
Sound Pressure Level ◽  
Sound Source ◽  
Sound Pressure ◽  
Natural Vibration ◽  
Ball Bearing ◽  
Pressure Level ◽  
Linear Velocity ◽  
Ball Bearings ◽  
Rate Of Increase ◽  
Measurement Results

The sound characteristics of linear guideway type (LGT) recirculating linear ball bearing driven at a constant linear velocity was studied. The measurement results of the sound characteristics showed that the LGT recirculating linear ball bearing has a sound property between line sound source and point sound source, and the measured overall sound pressure level increases with increasing the linear velocity of the carriage. The rate of increase of the overall sound pressure level to the linear velocity was analyzed combining the deduction of Yamada et al. and the results of previous studies on the collision sound. The results of this analysis match roughly the rate of increase of the measured overall sound pressure level to the linear velocity. We also observed the main peaks in the sound spectra of the LGT recirculating linear ball bearing itself. As a result, it was made clear that the main peaks are caused by the lower rolling natural vibration of the carriage, the pitching natural vibration of the carriage, and the vertical natural vibration of the carriage. In addition, the frequencies of the main peaks can be estimated by using presented expressions fRL, fP, and fv.

High Temperature Tribological Behavior of Nano-Al2O3 in Different Base Oils

2008 ◽  
Vol 373-374 ◽  
pp. 568-571 ◽  
Author(s):  
X.F. Sun ◽  
Yu Lin Qiao ◽  
Jia Wu He ◽  
Shi Ning Ma ◽  
C.H. Hu
Keyword(s):  
High Temperature ◽  
Ball Bearing ◽  
Tribological Behavior ◽  
Test System ◽  
High Load ◽  
Friction Coefficients ◽  
Base Oil ◽  
Base Oils ◽  
Al2o3 Particles ◽  
Reducing Properties

High temperature tribological behavior of nano-Al2O3 in different base oils were tested by a SRV multifunctional test system. The results show that the nano-Al2O3 particles can obviously improve the antiwear and friction reducing properties of the base oil under high temperature and high load. The friction coefficients of the base oil with added nano-Al2O3 are reduced about 35%, and abrasion loss reduces about 60%. When temperature is 500°C and load is 500N the pure base oil has lost lubricative function, but the base oil with added nano-Al2O3 can still remain the lower friction coefficients. Tribological behavior should be similar to the “ball bearing” lubrication action of the nano-Al2O3 particles, so the movement between the two tribological pairs becomes sliding/rolling.

AN ANALYSIS OF THE INFLUENCE OF CARBON NANOPARTICLES ADDITIVE ON SELECTED PROPERTIES OF LUBRICATING OILS

Tribologia ◽  
2021 ◽  
Vol 296 (2) ◽  
pp. 7-20
Author(s):  
Marcin Frycz ◽  
Mateusz Labuda
Keyword(s):  
Ignition Temperature ◽  
Carbon Nanoparticles ◽  
Experimental Tests ◽  
Viscosity Coefficient ◽  
Automatic Apparatus ◽  
Base Oil ◽  
Lubricating Oils ◽  
The Impact ◽  
C60 Fullerenes ◽  
Mineral Base

This paper presents the results of an analysis of the influence of the addition of various types of carbon nanoparticles on selected essential physical and operational properties of lubricating oils. Two selected oils, i.e. the mineral base oil without additives and the typical marine lubricating circulating oil Marinol RG 1240, were modified with the addition of shungite nanoparticles, graphite nanotubes, and C60 fullerenes. The mass fraction of modifiers was 0.2% wt for each of the additives. As part of the experimental tests, measurements were made of the impact of the above-mentioned modifiers on the change in the value of the ignition temperature of oils, the effect on the changes in the value of the dynamic viscosity coefficient in the aspect of changes of temperature and shear rate, as well as the impact on the changes in the friction coefficient and the size of the wear size scar. These tests were carried out on an EraFlash automatic apparatus for determining ignition temperature using the closed cup method, with a Haake Mars III research rheometer, and a T-02U tribometer with a four-ball head.

Pressure–Viscosity Coefficient of Hydrocarbon Base Oil through Molecular Dynamics Simulations

2015 ◽  
Vol 60 (3) ◽  
Author(s):  
Pinzhi Liu ◽  
Hualong Yu ◽  
Ning Ren ◽  
Frances E. Lockwood ◽  
Q. Jane Wang
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Viscosity Coefficient ◽  
Base Oil ◽  
Dynamics Simulations

The Effect of Pressure on the Non-Newtonian Behavior of Polymer Blended Petroleum Oils

1969 ◽  
Vol 91 (3) ◽  
pp. 459-462 ◽  
Author(s):  
J. D. Novak ◽  
W. O. Winer
Keyword(s):  
Shear Stress ◽  
Shear Strain ◽  
Atmospheric Pressure ◽  
Weight Percent ◽  
Elevated Pressure ◽  
Base Oil ◽  
Effect Of Pressure ◽  
Elevated Pressures ◽  
Capillary Type ◽  
Newtonian Behavior

The shear dependence of polymer containing oils at elevated pressure was observed in a capillary-type viscometer and is reported. Recoverable shear strain was not observed at elevated pressures but was observed at atmospheric pressure in the blends at the same shear stress. The fluids examined included a paraffinic base oil (B), B plus four and eight weight percent methacrylate, B plus four weight percent styrene, a naphthenic base oil (F), and F plus four weight percent methacrylate.

Absolute Viscosity of Air down to Cryogenic Temperatures and up to High Pressures

1973 ◽  
Vol 15 (4) ◽  
pp. 266-270 ◽  
Author(s):  
B. Latto ◽  
M. W. Saunders
Keyword(s):  
Experimental Data ◽  
High Pressure ◽  
Atmospheric Pressure ◽  
High Pressures ◽  
The Other ◽  
Cryogenic Temperatures ◽  
Temperature Range ◽  
Absolute Viscosity ◽  
Correlating Equations ◽  
Better Than

The absolute viscosity of gaseous air was determined experimentally for the general pressure and temperature range 100–15 000 kPa and 90–400 K respectively, using a series capillary transpiration-type viscometer which has been developed by the authors. The accuracy of the experimental data is believed to be better than ± 1 per cent. Two general correlating equations, one for atmospheric pressure and the other for medium high pressure (i.e., densities up to 400 kg/m3), have been obtained.

scholarly journals Service Life of Lubricating Grease in Ball Bearings (Part 1) Behavior of Grease and Its Base Oil in a Ball Bearing

2021 ◽  
Vol 16 (4) ◽  
pp. 236-245
Author(s):  
Tomonobu Komoriya ◽  
Ryosuke Ichimura ◽  
Tsuyoshi Kochi ◽  
Michitaka Yoshihara ◽  
Masataka Sakai ◽  
...  
Keyword(s):  
Service Life ◽  
Ball Bearing ◽  
Ball Bearings ◽  
Lubricating Grease ◽  
Base Oil

scholarly journals Assessment of an acoustic chamber for testing structure-borne sound transmission in a double-panel assembly

2021 ◽  
Author(s):  
Peter Bulski
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Performance Indicator ◽  
Sound Transmission ◽  
Pressure Level ◽  
Vibration Isolators ◽  
Acoustic Performance ◽  
Detailed Assessment ◽  
Vibratory Acceleration ◽  
Acoustic Chamber

An acoustic chamber was designed for testing structure-borne sound transmission in a double-panel assembly induced by point connectors. Several vibration isolators were tested and the overall effects on the noise transmitted through the assembly were predicted by establishing the link between the vibratory acceleration level (VAL) and the sound pressure level (SPL). A detailed assessment of the acoustic chamber showed that a major modification of the double-panel assembly is required before the acoustic performance of this assembly could be evaluated directly using insertion loss (IL) measurements where the sound pressure level (SPL) difference is the performance indicator. This thesis describes the assessment findings and retrofitting options. It is concluded that adjustments to the VAL-to-SPL relation are required to account for distance, radiation efficiency, and room effects. Further adjustments to the acoustic chamber are required to enhance its performance.

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