scholarly journals Evaluation of Electron-Beam Welded Hollow Balls for High-Speed Ball Bearings

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.

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.


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.


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.


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.


Author(s):  
Le Jiang ◽  
Yaguo Lyu ◽  
Wenjun Gao ◽  
Pengfei Zhu ◽  
Zhenxia Liu

Oil distribution inside the under-race lubricated bearing is crucial for lubrication and cooling of high-speed ball bearings. An under-race lubricated ball bearing is modeled to numerically investigate the effects of operating parameters and feed hole configuration on the distribution behavior of lubricant oil. The results of the numerical simulation indicate that the average oil volume fraction changes with a convex trend as the outer race rotating speed increases, while it changes monotonically with the inner race rotating speed, oil volume flow rate, and oil temperature. The extent of oil spreading on the outer race, cage, ball, and inner race decreases successively. Optimizing the feed hole configuration according to the average oil volume fraction is helpful to achieve precise lubrication of the under-race lubricated ball bearing.


2013 ◽  
Vol 376 ◽  
pp. 248-252
Author(s):  
Ming Yan ◽  
Ming Ming Wang ◽  
Xiang Jun Zhu

Load distribution, contact angle, rotate speed of rolling element, support stiffness of bearing, fatigue life and other aggregative indicators are got through the simulation statics analysis program of high speed ball bearing. Consequently, it is widely used in the engineering field. The domestic thesis about the simulation statics analysis program of the high speed ball bearing is barely reported, and most of the theoretical research thesis are not specific and have some mistakes. Consequently, aim for programming about a practical suit of the simulation statics analysis program of ball bearing, and the certain numerical problems are studied in the procedure of program.


1972 ◽  
Vol 94 (2) ◽  
pp. 117-122 ◽  
Author(s):  
W. J. Anderson ◽  
D. P. Fleming ◽  
R. J. Parker

The series-hybrid bearing couples a fluid-film bearing with a rolling-element bearing such that the rolling-element bearing inner race runs at a fraction of shaft speed. A series-hybrid bearing was analyzed and experiments were run at thrust loads from 100 to 300 lb and speeds from 4000 to 30,000 rpm. Agreement between theoretical and experimental speed sharing was good. The lowest speed ratio (ratio of ball bearing inner-race speed to shaft speed) obtained was 0.67. This corresponds to an approximate reduction in DN value of 1/3. For a ball bearing in a 3 million DN application, fatigue life would theoretically be improved by a factor as great as 8.


1975 ◽  
Vol 97 (2) ◽  
pp. 202-210 ◽  
Author(s):  
B. J. Hamrock

The motion of the ball and sliding friction in an arched outer-race ball bearing under thrust load is determined. Fatigue life evaluations were made. The analysis is applied to a 150 millimeter bore ball bearing. The results indicated that for high speed-light load applications the arched bearing has significant improvement in fatigue life over that of a conventional bearing. An arching of 0.254 mm (0.01 in.) was found to be an optimal. For an arched bearing it was also found that a considerable amount of spinning occurs at the outer race contacts.


1978 ◽  
Vol 100 (1) ◽  
pp. 40-45 ◽  
Author(s):  
R. J. Trippett

Little experimental data for losses of high-speed Conrad type ball bearings is presently found in the open literature. Hence the accuracy of published high-speed bearing-loss predictions is not known. Accurate predictions of high-speed ball bearing loss are important, however, in evaluating high-speed rotor support systems as well as determining cooling oil requirements for this type of bearing. The losses of a Conrad type ball bearing used to support the high-speed rotors in a vehicular gas turbine were measured. The effects of bearing axial load, rotor speed, lubricant viscosity, and lubricant flow rate on the bearing power consumption were determined. Power loss calculations, made from previously published equations for this type of bearing, did not correlate well with the measured high-speed bearing losses. New power loss equations are presented to predict the losses associated with high-speed deep-groove Conrad type ball bearings under well lubricated conditions.


2019 ◽  
Vol 12 (3) ◽  
pp. 248-261
Author(s):  
Baomin Wang ◽  
Xiao Chang

Background: Angular contact ball bearing is an important component of many high-speed rotating mechanical systems. Oil-air lubrication makes it possible for angular contact ball bearing to operate at high speed. So the lubrication state of angular contact ball bearing directly affects the performance of the mechanical systems. However, as bearing rotation speed increases, the temperature rise is still the dominant limiting factor for improving the performance and service life of angular contact ball bearings. Therefore, it is very necessary to predict the temperature rise of angular contact ball bearings lubricated with oil-air. Objective: The purpose of this study is to provide an overview of temperature calculation of bearing from many studies and patents, and propose a new prediction method for temperature rise of angular contact ball bearing. Methods: Based on the artificial neural network and genetic algorithm, a new prediction methodology for bearings temperature rise was proposed which capitalizes on the notion that the temperature rise of oil-air lubricated angular contact ball bearing is generally coupling. The influence factors of temperature rise in high-speed angular contact ball bearings were analyzed through grey relational analysis, and the key influence factors are determined. Combined with Genetic Algorithm (GA), the Artificial Neural Network (ANN) model based on these key influence factors was built up, two groups of experimental data were used to train and validate the ANN model. Results: Compared with the ANN model, the ANN-GA model has shorter training time, higher accuracy and better stability, the output of ANN-GA model shows a good agreement with the experimental data, above 92% of bearing temperature rise under varying conditions can be predicted using the ANNGA model. Conclusion: A new method was proposed to predict the temperature rise of oil-air lubricated angular contact ball bearings based on the artificial neural network and genetic algorithm. The results show that the prediction model has good accuracy, stability and robustness.


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