scholarly journals Discussion: “Effects of Ultra-Clean and Centrifugal Filtration on Rolling-Element Bearing Life” (Loewenthal, S. H., Moyer, D. W., and Needelman, W. M., 1982, ASME J. Lubr. Technol., 104, pp. 283–291)

1982 ◽  
Vol 104 (3) ◽  
pp. 291-292
Author(s):  
T. E. Tallian
Keyword(s):  
Rolling Element Bearing ◽  
Centrifugal Filtration ◽  
Bearing Life ◽  
Rolling Element ◽  
Element Bearing

Rolling Element Bearing Non-Linearity Effects

2000 ◽  
Author(s):  
N. S. Feng ◽  
E. J. Hahn
Keyword(s):  
Equations Of Motion ◽  
Rolling Element Bearing ◽  
Radial Clearance ◽  
Rotor Systems ◽  
Bearing Life ◽  
Rolling Element ◽  
Bearing Load ◽  
Rolling Elements ◽  
Element Bearing ◽  
Negative Clearance

Non-linearity effects in rolling element bearings arise from two sources, viz. the Hertzian force deformation relationship and the presence of clearance between the rolling elements and the bearing races. Assuming that centrifugal effects may be neglected and that the presence of axial preload is appropriately reflected in a corresponding change in the radial clearance, this paper analyses a simple test rig to illustrate that non-linear phenomena such as synchronous multistable and nonsynchronous motions are possible in simple rigid and flexible rotor systems subjected to unbalance excitation. The equations of motion of the rotor bearing system were solved by transient analysis using fourth order Runge Kutta. Of particular interest is the effect of clearance, governed in practice by bearing specification and the amount of preload, on the vibration behaviour of rotors supported by ball bearings and on the bearing load. It is shown that in the presence of positive clearance, there exists an unbalance excitation range during which the bearing is momentarily not transmitting force owing to contact loss, resulting in rolling element raceway impact with potentially relatively high bearing forces; and indicating that for long bearing life, operation with positive clearance should be avoided in the presence of such unbalance loading. Once the unbalance excitation is high enough to avoid such contact loss, it is the bearings with zero or negative clearance which produce maximum bearing forces.

scholarly journals Effects of Ultra-Clean and Centrifugal Filtration on Rolling-Element Bearing Life

1982 ◽  
Vol 104 (3) ◽  
pp. 283-291 ◽  
Author(s):  
S. H. Loewenthal ◽  
D. W. Moyer ◽  
W. M. Needelman
Keyword(s):  
Aircraft Engine ◽  
Surface Damage ◽  
Fatigue Tests ◽  
Rolling Element Bearing ◽  
Bearing Life ◽  
Deep Groove ◽  
Rolling Element ◽  
Element Bearing ◽  
High Level ◽  
Better Than

Fatigue tests were conducted on groups of 65-millimeter bore diameter deep-groove ball bearings in a MIL-L-23699 lubricant under two levels of filtration. In one test series, the oil cleanliness was maintained at an exceptionally high level (better than a class of “00” per NAS 1638) with a 3 micron absolute barrier filter. These tests were intended to determine the “upper limit” in bearing life under the strictest possible lubricant cleanliness conditions. In the tests using a centrifugal oil filter, contaminants of the type found in aircraft engine filters were injected into the filters’ supply line at 125 milligrams per bearing-hour. “Ultra-clean” lubrication produced bearing fatigue lives that were approximately twice that obtained in previous tests with contaminated oil using 3 micron absolute filtration and approximately three times that obtained with 49 micron filtration. It was also observed that the centrifugal oil filter had approximately the same effectiveness as a 30 micron absolute filter in preventing bearing surface damage.

scholarly journals A New Criterion for Predicting Rolling-Element Fatigue Lives of Through-Hardened Steels

1973 ◽  
Vol 95 (3) ◽  
pp. 287-293 ◽  
Author(s):  
J. L. Chevalier ◽  
E. V. Zaretsky ◽  
R. J. Parker
Keyword(s):  
Room Temperature ◽  
Rolling Element Bearing ◽  
Tempering Temperature ◽  
Bearing Life ◽  
Material Hardness ◽  
Rolling Element ◽  
Carbide Size ◽  
Element Bearing ◽  
New Criterion ◽  
Carbide Particles

A carbide factor was derived based upon a statistical analysis which related rolling-element fatigue life to the total number of residual carbide particles per unit area, median residual carbide size, and percent residual carbide area. An equation was empirically determined which predicts material hardness as a function of temperature. The limiting temperatures of all of the materials studied were dependent on initial room temperature hardness and tempering temperature. An equation was derived combining the effects of material hardness, carbide factor, and bearing temperature to predict rolling-element bearing life.

scholarly journals Measurement of vibrations occurring in rolling bearings

Mechanik ◽  
2017 ◽  
Vol 90 (8-9) ◽  
pp. 734-736
Author(s):  
Stanisław Adamczak ◽  
Mateusz Wrzochal ◽  
Paweł Zmarzły
Keyword(s):  
Rolling Bearing ◽  
Measurement Methods ◽  
Rolling Element Bearing ◽  
Vibration Measurement ◽  
Dynamic Measurements ◽  
Rolling Bearings ◽  
Life Period ◽  
Bearing Life ◽  
Rolling Element ◽  
Element Bearing

There are three criteria the vibration measurement methods as applied at each stage of the rolling-element bearing life period could be classified to. Analysis of these methods is suggested for better understanding of the rolling bearing operating problems and of the issues related to dynamic measurements.

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