scholarly journals Impact Analysis of Mutual Rotation of Roller Bearing Rings on the Process of Contact Stresses in Rolling Elements

2013 ◽  
Vol 13 (1) ◽  
pp. 50-54 ◽  
Author(s):  
Lenka Jakubovičová ◽  
Milan Sága ◽  
Milan Vaško
Keyword(s):  
Impact Analysis ◽  
Roller Bearing ◽  
Contact Stresses ◽  
Rolling Elements ◽  
Bearing Rings ◽  
Mutual Rotation

scholarly journals The dependence of performance characteristics of roller bearing on material used

2021 ◽  
pp. 41-45
Author(s):  
D. B. Grits ◽  
Keyword(s):  
Roller Bearing ◽  
Contact Stresses ◽  
Rolling Stock ◽  
Steel Shkh15 ◽  
Alternative Materials ◽  
Rolling Elements ◽  
Bearing Assembly ◽  
Bearing Rings ◽  
Maximum Contact ◽  
12Kh18n9t Steel

The main materials for the manufacture of rolling stock bearing assemblies are steel ShKh15, ShKh15SG, ShKh4. The article discusses the possibility of using steels 20Kh2N4A, 95Kh18-Sh, 12Kh18N9T as alternative materials, an assessment of the arising contact stresses on the surfaces of the raceways of the bearing rings and rolling elements is given. When using 12Kh18N9T steel, the maximum contact stresses are reduced by 4 % in comparison with standard materials, which can provide an increase in the resource of the bearing assembly.

Analysis of a Rolling-Element Idler Gear Bearing Having a Deformable Outer-Race Structure

1963 ◽  
Vol 85 (2) ◽  
pp. 273-278 ◽  
Author(s):  
A. B. Jones ◽  
T. A. Harris
Keyword(s):  
Fatigue Life ◽  
High Speed ◽  
Roller Bearing ◽  
Rolling Element Bearing ◽  
Outer Ring ◽  
Outer Race ◽  
Rolling Element ◽  
Rolling Elements ◽  
Planet Gear ◽  
Bearing Rings

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.

scholarly journals CYLINDRICAL ROLLER BEARING LUBRICATION REGIMES ANALYSIS AT LOW SPEED AND PURE RADIAL LOAD

2019 ◽  
Vol 59 (3) ◽  
pp. 272-282
Author(s):  
Jakub Chmelař ◽  
Karel Petr ◽  
Petr Mikeš ◽  
Vojtěch Dynybyl
Keyword(s):  
Roller Bearing ◽  
Radial Load ◽  
Lubrication Regimes ◽  
Lubrication Film ◽  
Press Fit ◽  
Lubrication Regime ◽  
Rolling Element ◽  
Rolling Elements ◽  
Cylindrical Roller Bearing ◽  
Bearing Rings

In this article, we describe a method of the roller bearing lubrication regime prediction. It uses a mathematical model of the bearing based on the standard ISO/TS 16281 to obtain the external load distribution over the rolling elements. We consider the effects of press fit and thermal gradient etween bearing rings on the internal clearance. The model is limited to an input of an uni-axial radial load and it neglects the centrifugal forces and gyroscopic moments due to its application for the region of low speeds. The lubrication film thickness is evaluated for the most loaded rolling element by a numerical solution of Reynolds’ equation for the line contact. The assessment of the lubrication regime takes into the account the surface roughness by employing the lubrication coefficient as an output parameter. Presented outcomes of the study, based on the measured geometry of the bearing, show the importance of an appropriate lubricant selection for the application.

The Rotational Accuracy Characteristics of the Preloaded Hollow Roller Bearing

1981 ◽  
Vol 103 (1) ◽  
pp. 6-12 ◽  
Author(s):  
C. P. Bhateja ◽  
R. D. Pine
Keyword(s):  
Roller Bearing ◽  
Design Parameters ◽  
Annular Space ◽  
Dynamic Nature ◽  
Cyclic Pattern ◽  
Radial Bearing ◽  
Geometrical Features ◽  
Present Context ◽  
Rolling Elements ◽  
Inner Race

The rotational characteristics of the cageless, hollow roller radial bearing are investigated. The preloading of the hollow rolling elements in the annular space between the inner and the outer races in such a bearing provides a well controlled and consistent shaft rotational pattern. This pattern is determined by the dimensional and geometrical features of the rollers’ external and internal diameters and roundnesses, the outer and inner ring raceway roundnesses and the eccentricity of the inner race with respect to the shaft axis. The various patterns of shaft runout associated with these causes are identified and the sensitivity of the shaft runout to these factors is examined qualitatively and quantitively. The shaft runout in the present context is not merely the initial static offset of the shaft axis, but is a dynamic, cyclic pattern consisting of certain frequencies resulting from the geometrical features of the bearing components. The somewhat elusive, complex and dynamic nature of this apparent shaft runout makes it difficult to be measured. In addition, the importance of the need to control the circumferential clearance to a minimum is demonstrated. It is thus shown that through the proper control of the component geometry and certain design parameters, the hollow roller bearing can provide an extremely accurate bearing for precision applications.

scholarly journals Modeling and Dynamic Analysis of Spherical Roller Bearing with Localized Defects: Analytical Formulation to Calculate Defect Depth and Stiffness

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Behnam Ghalamchi ◽  
Jussi Sopanen ◽  
Aki Mikkola
Keyword(s):  
Dynamic Model ◽  
Contact Stiffness ◽  
Roller Bearing ◽  
Measurement Data ◽  
Contact Forces ◽  
Hertzian Contact ◽  
Radial Clearance ◽  
Outer Race ◽  
Rolling Elements ◽  
Localized Defects

Since spherical roller bearings can carry high load in both axial and radial direction, they are increasingly used in industrial machineries and it is becoming important to understand the dynamic behavior of SRBs, especially when they are affected by internal imperfections. This paper introduces a dynamic model for an SRB that includes an inner and outer race surface defect. The proposed model shows the behavior of the bearing as a function of defect location and size. The new dynamic model describes the contact forces between bearing rolling elements and race surfaces as nonlinear Hertzian contact deformations, taking radial clearance into account. Two defect cases were simulated: an elliptical surface on the inner and outer races. In elliptical surface concavity, it is assumed that roller-to-race-surface contact is continuous as each roller passes over the defect. Contact stiffness in the defect area varies as a function of the defect contact geometry. Compared to measurement data, the results obtained using the simulation are highly accurate.

Analysis of radial roller bearing rating life in complex loading conditions

2021 ◽  
pp. 1-27
Author(s):  
Vladimir Ivannikov ◽  
Mikhail Leontiev ◽  
Sergey Degtyarev ◽  
Valeriy Popov
Keyword(s):  
High Performance ◽  
Roller Bearing ◽  
Complex Loading ◽  
Contact Forces ◽  
Loading Conditions ◽  
Jet Engines ◽  
Inertia Effects ◽  
Internal Contact ◽  
Rolling Elements ◽  
Life Analysis

Abstract An approach for accurate life analysis of radial roller bearings in complex loading conditions is presented. It employs ISO~16281 and accounts not only for external radial loads applied to the inner ring, but also for (i) internal bearing clearance, (ii) flexibility of the bearing rings, (iii) rings out-of-roundness, (iv) inertia effects, (v) rolling elements profile and (vi) rings misalignment. In the last decades these factors have been becoming more and more important for modern high-performance jet engines, whose shafts are commonly hollow and the housing and the rings thicknesses may be of comparable magnitudes. To obtain the distribution of internal contact forces, an advanced static model of a bearing with deformable, potentially misaligned, rings is developed. The bending deformations of the rings are reproduced superimposing deformed shapes from each of the arising internal contact force applied individually. Bearing rollers are allowed to have non-cylindrical profile, its geometry is approximated by means of slices each having constant diameter. A robust numerical scheme for solving the resultant set of equations with the aid of the barrier functions method is constructed. To increase even further the accuracy of rating life analysis, distributions of the contact stresses between the roller and the ring surfaces, obtained by solving numerically the problem of non-Hertzian interaction, are added to computations. A numerical benchmark test is presented to demonstrate the applicability of the developed approach. It shows how the aforementioned factors influence the bearing contact forces and its rating life.

Paper 14: Measurement of Film Thickness in a Taper Roller Bearing

1969 ◽  
Vol 184 (12) ◽  
pp. 103-110
Author(s):  
D. A. Jones ◽  
A. B. Crease
Keyword(s):  
Film Thickness ◽  
Surface Finish ◽  
Thrust Bearing ◽  
Roller Bearing ◽  
Rolling Contacts ◽  
Rolling Elements ◽  
Elastohydrodynamic Film Thickness ◽  
Taper Roller Bearing

This paper describes an attempt to measure the elastohydrodynamic film thickness generated within the rolling contacts of a conventional taper roller thrust bearing. The technique used is simple and unambiguous and should be capable of application irrespective of the surface finish or geometry of the rolling elements.

Theoretical Study on the Influence of Planet Gear Rim Thickness and Bearing Clearance on Calculated Bearing Life

2019 ◽  
Vol 142 (3) ◽  
Author(s):  
Andreas Fingerle ◽  
Jonas Hochrein ◽  
Michael Otto ◽  
Karsten Stahl
Keyword(s):  
High Efficiency ◽  
Roller Bearing ◽  
The Body ◽  
Fem Model ◽  
Bearing Life ◽  
Bearing Load ◽  
Rolling Elements ◽  
Planet Gear ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller

Abstract Planetary gearboxes are becoming more popular due to their high-power density and potentially high efficiency. When the planet bearings are internally mounted, the body of the planet gear has to be hollow. The demand for large outer diameters due to high-load requirements might result in a small planet rim thickness. Depending on the rim thickness, its rigidity may become very low. Due to the low stiffness and the special load conditions caused by the double meshing, the deformation of the planet and its bearings are unique. In this paper, the influence of rim thickness on bearing load and lifetime is examined. The analysis is performed with a finite element method (FEM) model of a planet rim with a built-in cylindrical roller bearing. With the resulting planet deformation from the FEM calculation, the load distribution on the rolling elements in the bearing and the bearing lifetime according to ISO/TS 16281:2008 has been evaluated.

Theoretical Study on the Influence of Planet Gear Rim Thickness and Bearing Clearance on Calculated Bearing Life

2019 ◽  
Author(s):  
Andreas Fingerle ◽  
Jonas Hochrein ◽  
Michael Otto ◽  
Karsten Stahl
Keyword(s):  
High Efficiency ◽  
Roller Bearing ◽  
The Body ◽  
Fem Model ◽  
Bearing Life ◽  
Bearing Load ◽  
Rolling Elements ◽  
Planet Gear ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller

Abstract Planetary gearboxes are becoming more popular due to their high power density and potentially high efficiency. When the planet bearings are internally mounted, the body of the planet gear has to be hollow. The demand for large outer diameters due to high load requirements might result in a small planet rim thickness. Depending on the rim thickness, its rigidity may become very low. Due to the low stiffness and the special load conditions caused by the double meshing, the deformation of the planet and its bearings are unique. In this paper, the influence of rim thickness on bearing load and lifetime are examined. The analysis is performed with an FEM model of a planet rim with a built-in cylindrical roller bearing. With the resulting planet deformation from the FEM calculation, the load distribution on the rolling elements in the bearing and the bearing lifetime according to ISO/TS 16281:2008 have been evaluated.

Fatigue Life Prediction for Large-Diameter Elastically Constrained Ball Bearings

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Jerzy T. Sawicki ◽  
Samuel A. Johansson ◽  
John H. Rumbarger ◽  
Ronald B. Sharpless
Keyword(s):  
Fatigue Life ◽  
Load Distribution ◽  
Life Prediction ◽  
Large Diameter ◽  
Roller Bearing ◽  
Fatigue Life Prediction ◽  
Design Criteria ◽  
Standard Design ◽  
Critical Components ◽  
Bearing Rings

The application of large-diameter bearing rings and the thereof inherited low stiffness make them susceptible to local distortions caused by their surrounding structures, which are often under heavy loads. The standard accepted design criteria for these bearings are based on the estimation of the internal load distribution of the bearing, under the assumption of rigid circular and flat supporting structures, that keep the bearing inner and outer races in circular, flat, i.e., not deformed shapes. However, in the presence of structural distortions, the element load distribution can be severely altered and cannot be predicted via the standard design criteria. Therefore, the application of large-diameter ball and roller bearing rings as the critical components in rotating machines becomes more of a design task than making a catalog selection. The analytical and finite element approach for fatigue life prediction of such a bearing application is presented. The undertaken approach and the results are illustrated based on the analysis and fatigue life simulation of the computed tomography scanner’s main rotor bearing. It has been demonstrated that flexibility of the rings can significantly reduce the fatigue life of the ball bearing.

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