scholarly journals Rolling-Element Fatigue Lives of Through-Hardened Bearing Materials

1972 ◽  
Vol 94 (2) ◽  
pp. 165-171 ◽  
Author(s):  
R. J. Parker ◽  
E. V. Zaretsky

Rolling-element fatigue tests were run with eight through-hardened bearing materials at 150 deg F. One-half in. dia balls of each material were run in five-ball fatigue testers. Care was taken to maintain constant all variables known to affect rolling-element fatigue life. The longest lives at 150 deg F were obtained with AISI 52100. Ten-percent lives of the other materials ranged from 7 to 78 percent of that obtained with 52100. A trend is indicated toward decreased rolling-element fatigue life with increased total weight percent of alloying elements. Three groups of 120-mm bore ball bearings made from AISI M-1, AISI M-50, and WB-49 were fatigue tested at an outer-race temperature of 600 deg F. The 10-percent lives of the M-50 and M-1 bearings exceeded the calculated AFBMA life by factors of 13 and 6, respectively. The bearings with WB-49 races showed lives less than AFBMA life. The results of the bearing tests at 600 deg F correlate well with the results of the five-ball fatigue data at 150 deg F.

1971 ◽  
Vol 93 (1) ◽  
pp. 47-55 ◽  
Author(s):  
Harold H. Coe ◽  
Richard J. Parker ◽  
Herbert W. Scibbe

An experimental investigation was performed with two series (115 and 215) of 75 mm bore ball bearings using hollow balls as the rolling elements. The bearings were tested at 500 and 1000 pounds thrust loads at shaft speeds up to 24000 rpm. The 115 series bearings with 1/2-in. SAE 52100 steel balls showed very little difference in torque, outer-race temperature, or rolling-element fatigue life when compared to similar data for a solid ball bearing. The 215 series bearings with 11/16-in. AISI M-50 steel balls showed only slight differences in torque and outer-race temperature but a very significant decrease in rolling-element fatigue life compared to a solid ball bearing. The balls failed in flexure fatigue, due to a stress concentration in the weld area.


1979 ◽  
Author(s):  
C. F. Bersch ◽  
Philip Weinberg

The feasibility of using hot-pressed silicon nitride (HPSN) for rolling elements and for races in ball bearings and roller bearings has been explored. HPSN offers opportunities to alleviate many current bearing problems including DN and fatigue life limitations, lubricant and cooling system deficiencies, and extreme environment demands. The history of ceramic bearings and the results of various element tests, bearing tests in rigs, and bearing tests in a turbine engine will be reviewed. The advantages and problems associated with the use of HPSN in rolling element bearings will be discussed.


2021 ◽  
Vol 143 (11) ◽  
Author(s):  
Iqbal Shareef ◽  
Joshua A. Brandes ◽  
Erwin V. Zaretsky

Abstract Static Load Capacity as defined by Palmgren is the load (stress) applied to a bearing that results in an indentation greater than 0.0001 times the diameter of the rolling element. The effect of hardness on the Static Load Capacity of AISI 52100 bearing steel heat treated to six different hardnesses was investigated. Indentation, depth, diameter, volume, and surface area were measured by the white light interferometer. A total of 468 hardness ball–plate combination tests were conducted. For a given plate (race) hardness, the Static Load Capacity was dependent on plate (race) hardness and independent of mating ball hardness from Rockwell C 56 to 66. For plate (race) hardness between Rockwell C 56 and 60, the Static Load Capacity was relatively constant. At Rockwell C hardness between 60 and 61, the Static Load Capacity increased and then rapidly decreased at a plate hardness of Rockwell C 66, below that value obtained at Rockwell C 56. Experimental results obtained for Static Load Capacity using the Palmgren criteria correlated with the finite element analysis for ball-on-plate indentation but not with Hertz theory. The Static Load Capacity based on Yhland for ball bearings was equal to a maximum Hertz stress of 3.71 GPa (538 ksi) at a ball-race conformity of 52%. This value is 12% lower than that specified in the ISO and ANSI/ABMA Bearing Standards. The manufacturers’ Static Load Rating can be reduced from 4% to 7% for ball bearings and from 8% to 25% for roller bearings.


1999 ◽  
Author(s):  
Hassan Mahfuz ◽  
Kamruz Zaman ◽  
Anwarul Haque ◽  
Uday Vaidya ◽  
Hisham Mohamed ◽  
...  

Abstract Fatigue life prediction of thick-section S2-Glass fiber reinforced Vinylester composites has been studied analytically using fatigue modulus concept. Flexural fatigue tests were conducted under three point bend configuration. A stress ratio of R = 0.1 and a frequency of 3 Hz has been used for the fatigue tests. Fatigue data have been generated at five load levels; 85%, 80%, 70%, 60% and 55% of the ultimate flexural strength. Using these fatigue data, S-N diagram has been generated. Fatigue modulus has been determined by the slope of the line drawn on a plot of applied stress vs. resultant strain at specific loading cycle. Since fatigue modulus degrades with cycle number, it was assumed that the degradation rate follows a power function of fatigue cycle. Using this concept, a practical and applicable equation for predicting fatigue life is established. The Fatigue Life Prediction method used in this investigation requires two distinct parameters, namely applied stress level and two material constants. These material constants have been determined from the fatigue test data. A comparison has been made between the analytical prediction and the experimentally obtained S-N curve. The correlation between the two has been observed to be excellent. Flexural failure modes have also been identified as extensive delamination, fiber fracture and fiber kinking. Microscopic observation shows that all failures are predominantly on the tensile side with slight fiber kinking and matrix crushing on the compression side.


1962 ◽  
Vol 84 (1) ◽  
pp. 181-189 ◽  
Author(s):  
W. J. Greenert

An understanding of the basic mechanics and statistical variables of the contact roller test as it is applied to surface fatigue phenomena was obtained. One hundred ninety-four contact rollers of AISI 52100 bearing quality steel were tested to establish dispersion limits. No significant fatigue differences were indicated for heats, bars, or test replications among steels of similar quality, composition, and heat-treatment. A statistical evaluation of results points to the contact roller test as a suitable means for studying significant variables that pertain to both the theoretical and material aspects of antifriction bearings. Stresses in the contact surfaces based on the orthogonal shear-stress theories showed good correlation with fatigue life.


1963 ◽  
Vol 85 (2) ◽  
pp. 273-278 ◽  
Author(s):  
A. B. Jones ◽  
T. A. Harris

Conventional calculations of ball and roller bearing carrying capacity and fatigue life assume that the raceway bodies are rigid structures and that all elastic deformation occurs at the rolling elements’ contact with the raceways. In many instances, and particularly with aircraft applications, the bearing rings and their supports cannot be considered rigid. One such application is the planet gear in a transmission. This report develops a theory whereby the effects of the elastic distortions of the outer race of a rolling-element bearing on the internal load distribution and fatigue life of the bearing can be considered. The theory has been programmed for a high-speed, digital computer. An example of calculation for a planet gear roller bearing whose outer race is integral with the gear and of relatively thin section is given. The distortions of the flexible outer ring cause a significantly lower bearing fatigue life (L10) than would occur if the outer ring were rigid and considering a practical range of bearing diametral clearances. Mr. Jones developed the theoretical analysis for this paper and Mr. Harris provided the programming and the experimental data.


1975 ◽  
Vol 97 (3) ◽  
pp. 350-355 ◽  
Author(s):  
R. J. Parker ◽  
E. V. Zaretsky

Hot-pressed silicon nitride was evaluated as a rolling-element bearing material. This material has a low specific gravity (41 percent that of bearing steel) and has a potential application as low mass balls for very high-speed ball bearings. The five-ball fatigue tester was used to test 12.7-mm- (0.500-in-) dia silicon nitride balls at maximum Hertz stresses ranging from 4.27 × 109 N/m2 (620,000 psi) to 6.21 × 109 N/m2 (900,000 psi) at a race temperature of 328K (130 deg F). The fatigue life of NC-132 hot-pressed silicon nitride was found to be equal to typical bearing steels and much greater than other ceramic or cermet materials at the same stress levels. A digital computer program was used to predict the fatigue life of 120-mm- bore angular-contact ball bearings containing either steel or silicon nitride balls. The analysis indicates that there is no improvement in the lives of bearings of the same geometry operating at DN values from 2 to 4 million where silicon nitride balls are used in place of steel balls.


2013 ◽  
Vol 198 ◽  
pp. 651-656 ◽  
Author(s):  
Marijonas Bogdevičius ◽  
Viktor Skrickij

The paper considers the dynamics of ball bearings with defects. A mathematical model of a ball bearing with defects is offered. The performed theoretical and experimental investigations of ball bearings with defects are described. Five cases of various defects are investigated, including the defective outer race, the defective inner race, the defective rolling element, the defective inner and outer races, the rolling element and a separator, the worn-out ball bearing.


1978 ◽  
Vol 100 (2) ◽  
pp. 226-232 ◽  
Author(s):  
R. J. Parker ◽  
R. S. Hodder

The rolling-element fatigue lives of AMS 5749 and AISI M-50 were compared in tests run in the five-ball fatigue tester and the rolling-contact (RC) fatigue tester. The effects of double vacuum melting and retained austenite on the life of AMS 5749 were determined in five-ball fatigue tests. The double vacuum melting process consisted of induction vacuum melting followed by vacuum arc remelting (VIM-VAR). In the five-ball tests, VIM-VAR AMS 5749 gave lives at least six times that of VIM-VAR AISI M-50. Similar tests in the rolling-contact (RC) fatigue tester showed no significant difference in the lives of the two materials. The rolling-element fatigue life of VIM-VAR AMS 5749 was at least 14 times that of vacuum induction melted AMS 5749. A trend toward increased rolling-element fatigue life with decreased retained austenite is apparent, but the confidence that the all experimental differences are significant is not great. The highest level of retained austenite, 14.6 percent, is, however, significantly detrimental to rolling-element fatigue life, relative to the intermediate level of 11.1 percent.


Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 798
Author(s):  
Ruth Acosta ◽  
Haoran Wu ◽  
Ramanan Sridaran Venkat ◽  
Fabian Weber ◽  
Jochen Tenkamp ◽  
...  

The service life of materials and components exposed to repeated mechanical loads is limited, which is why the understanding of the damage evolution and estimating its fatigue life is of high importance for its technical application. This paper shows how temperature and magnetic field measurement methods can be used to describe the cyclic deformation behaviour of metallic materials and to derive parameters from this, which are used in short-term methods to calculate the fatigue life. Within the SteBLife (stepped-bar fatigue life) approach, only three to five fatigue tests with a stepped fatigue specimen are required to determine a complete S–N or Woehler curve with scatter bands for different failure probabilities. If only a trend S–N curve is required, the number of tests can be reduced to a single fatigue test only. In the framework of this paper, these approaches will be presented for normalised SAE 1045 (C45E) and quenched and tempered SAE 4140 (42CrMo4) steels.


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