Bearings, airframe rolling. Rigid double row ball bearings in steel. Dimensions and loads

2015 ◽  
Keyword(s):  
Ball Bearings ◽  
Double Row

IP Dynamic Anti-Rust Test, Lubricating Greases

1969 ◽  
Vol 184 (6) ◽  
pp. 23-31
Author(s):  
F. E. H. Spicer
Keyword(s):  
Performance Level ◽  
Test Method ◽  
European Countries ◽  
Distilled Water ◽  
Ball Bearings ◽  
Double Row ◽  
Performance Levels ◽  
Good Protection ◽  
Intermediate Performance

The Institute of Petroleum has recently published a test method (IP 220/67) for assessing the rust-prevention characteristics of greases. Specially selected and preserved double-row, self-aligning ball bearings are used as test specimens. The test, which lasts for 164 1/2 h, is dynamic, the grease film being produced and part of the test being performed with the bearings rotating partially submerged in distilled water. The performance of the grease is assessed by estimating the area of rust on the outer races of the test bearings. The precision of the test method was established by an extensive international correlation programme involving 30 laboratories from five European countries. This showed a precision which varied according to the performance level of the test greases. The results of tests with greases affording very good protection and with greases affording very poor protection against rusting gave better precision than results from greases with intermediate performance levels.

Measuring and Analyzing the Moment of Friction in Double-Row Ball Bearings

2013 ◽  
Vol 199 ◽  
pp. 149-154
Author(s):  
Robert Korbut ◽  
Jerzy Nachimowicz
Keyword(s):  
Experimental Data ◽  
Working Conditions ◽  
Ball Bearing ◽  
Ball Bearings ◽  
Double Row ◽  
The Moment ◽  
Working Resistance ◽  
The Given

On the basis of the experiment, the changes in the moment of friction in the double-row ball bearing were estimated. The experimental data indicated the presence of significant differences between the average values of the moment of friction in the whole spectrum of the rotational speeds that were examined. At the same time it was observed that there exist certain characteristic rotational speeds at which the given bearing is informed by a greater working resistance. It may indicate the presence of both optimal and unfavourable working conditions for these bearings; the conditions during which there occur minimal or, respectively, maximal resistances (in a given situation). The results of the examination were analyzed statistically; the after-examination samples were closely observed and this further visual scrutiny proved that during the work of the bearing, the lubricant was displaced.

Nonlinear Forced Oscillations Caused by Quartic Nonlinearity in a Rotating Shaft System

1990 ◽  
Vol 112 (3) ◽  
pp. 288-297 ◽  
Author(s):  
Y. Ishida ◽  
T. Ikeda ◽  
T. Yamamoto
Keyword(s):  
Polar Coordinates ◽  
Forced Oscillations ◽  
Ball Bearings ◽  
Rotating Shaft ◽  
Restoring Force ◽  
Double Row ◽  
Nonlinear Component ◽  
Shaft System ◽  
Nonlinear Components ◽  
Theoretical Results

This paper deals with nonlinear forced oscillations in a rotating shaft system which are caused by quartic nonlinearity in a restoring force. These oscillations are theoretically analyzed by paying attention to the nonlinear components represented by the polar coordinates. It is clarified which kind of nonlinear component has an influence on each oscillation. In experiments it was shown that, when the shaft was supported by double-row angular contact ball bearings, the restoring force had nonlinear spring characteristics involving quartic nonlinearity in addition to quadratic and cubic ones. Experimental results were compared with the theoretical results regarding the probability of occurrence and the shapes of the resonance curves.

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