Effects of Load Distribution on Life of Radial Roller Bearings

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
Takafumi Nagatomo ◽  
Ken Takahashi ◽  
Yoshiaki Okamura ◽  
Takehiko Kigawa ◽  
Shoji Noguchi
Keyword(s):  
Load Distribution ◽  
Rolling Bearing ◽  
Outer Ring ◽  
Contact Conditions ◽  
Internal Load ◽  
Load Distributions ◽  
Bearing Life ◽  
Rolling Elements ◽  
Endurance Tests ◽  
Bearing Rings

An external load applied to a radial rolling bearing is distributed among the rolling elements. In many applications, the bearing internal load distribution may be altered by the elastic deformations of the bearing rings. This alteration can have an effect on bearing life. The objective of this study is to investigate the effect of load distribution on bearing life, both theoretically and experimentally, using several housing models which provide different contact conditions between the housing bore and the outer ring. This paper first presents a newly developed method of determining dynamic load distributions with an optical fiber strain sensor. The measurements of the load distribution for the housing models by using this method have shown that the contact condition between the housing bore and the outer ring affects the load distribution, and the effect of the load distribution on the bearing life has been confirmed by the theoretical calculation of the bearing life. Furthermore, endurance tests using dented bearings were performed to validate the effect of load distribution on bearing life. The results of the tests have substantiated that the bearing life is substantially affected by the load distribution; moreover, it has been shown that there is a linear relationship between the calculated lives and the experimental ones.

Investigation of the Effect of Rolling Bearing Construction on Internal Load Distribution and the Number of Active Rolling Elements

2013 ◽  
Vol 633 ◽  
pp. 103-116 ◽  
Author(s):  
Radoslav Tomovic
Keyword(s):  
Load Distribution ◽  
Load Transfer ◽  
Rolling Bearing ◽  
Radial Clearance ◽  
Radial Load ◽  
Rolling Bearings ◽  
Internal Load ◽  
Ring Support ◽  
Rolling Elements

One of the most important characteristics of a rolling bearing is the load distribution on rolling elements. This paper provides an analysis on the influence of the internal construction of rolling bearings on load distribution and the number of active rolling elements. The analysis was performed using a new mathematical model for the boundary level calculations of the bearing deflection and external radial load for the inner ring support onqrolling bearing elements. The model considers two boundary positions of inner ring support on an even and odd number of rolling elements. The developed model enables a very simple determination of the number of active rolling elements participating in an external load transfer, depending on the bearing type and internal radial clearance.

scholarly journals EXPERIMENTAL APPLICATIONS ON THE INFLUENCE OF INTERNAL OPERATION CLEARANCE OF THE FAULTY ROLLING BEARINGS UPON THEIR REMAINING LIFETIME

2017 ◽  
Vol 20 (1) ◽  
Author(s):  
DUMITRU-CRISTINEL NADABAICA ◽  
VALENTIN NEDEFF ◽  
LUMINITA BIBIRE ◽  
NARCIS BÂRSAN
Keyword(s):  
Experimental Study ◽  
Temperature Difference ◽  
Work Load ◽  
Rolling Bearing ◽  
Operating Conditions ◽  
Outer Ring ◽  
Rolling Bearings ◽  
Rolling Elements ◽  
Bearing Rings

<p>In the calculation of the rolling bearings lifetime are taking in to consideration the distribution of the work load on each rolling elements, obliquity, internal operation clearance and pre-stressing. In the case of a rolling bearing with a defect, the internal operation clearance have an influence upon the evolution of its deterioration and remaining lifetime by: internal manufacturing clearance; the expansion of the inner ring when the rolling bearing is mounted on a adapter sleeve; the contraction of the outer ring when the rolling bearing is mounted in the housing; and the temperature difference between rolling bearing rings during operation. This paper presents an experimental study regarding to the influence of the internal operation clearance of the ZKL 1205K rolling bearing upon the remaining lifetime in same operating conditions. </p>

Static Rolling Bearing Models in a C.A.D. Environment for the Study of Complex Mechanisms: Part II—Complete Assembly Model

1999 ◽  
Vol 121 (2) ◽  
pp. 215-223 ◽  
Author(s):  
A. Bourdon ◽  
J. F. Rigal ◽  
D. Play
Keyword(s):  
Stiffness Matrix ◽  
Load Distribution ◽  
Nonlinear Behavior ◽  
Rolling Bearing ◽  
Finite Element Models ◽  
Complex Mechanism ◽  
Assembly Model ◽  
Rolling Element ◽  
Complex Mechanical Systems ◽  
Bearing Rings

This is the second part of two companion papers, the first of which is “Static Rolling Bearing Models in a C.A.D. Environment for the Study of Complex Mechanism: Part I—Rolling Bearing Model.” A general methodology for the accurate modeling of the nonlinear behavior of ball and roller bearings is proposed. A stiffness matrix is defined both for each rolling element and for the complete rolling bearing. Thus, it can be introduced into standard finite element models of complex mechanical systems, with the aim of predicting mechanical behavior and load and strain distributions. This method is applied to two cases of helicopter and automobile gearboxes. Deformable bearing rings considerably modify contact angle and load distribution, thus the coefficient values of the stiffness matrix are different from the classical values. The paper highlights how important it is to consider an overall model of the mechanical system rather than a local one in the vicinity of the bearings.

Design of Four Contact-Point Slewing Bearing With a New Load Distribution Procedure to Account for Structural Stiffness

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
Mireia Olave ◽  
Xabier Sagartzazu ◽  
Jorge Damian ◽  
Alberto Serna
Keyword(s):  
Load Distribution ◽  
Contact Point ◽  
Element Model ◽  
Contact Forces ◽  
Elastic Model ◽  
Slewing Bearing ◽  
Extreme Loads ◽  
Highly Nonlinear ◽  
Rolling Elements ◽  
Bearing Rings

This paper proposes a procedure for obtaining the load distribution in a four contact-point slewing bearing considering the effect of the structure’s elasticity. The uneven stiffness of the rings and the supporting structures creates a variation with respect to the results obtained with a rigid model. It is necessary to evaluate the effect of the elasticity on the increase in the contact forces in order to be able to design the slewing bearing and the structures involved in the connection. Depending on the shape of the structures, the contact force value obtained on the most loaded rolling element is different. The evaluation of this maximum force at extreme loads is essential to design the structures joined to the bearing rings. The new elastic model presented in this paper is highly nonlinear so iterative loops are needed in order to obtain a satisfactory solution. At the same time a finite element model (FEM) has been created for the global model, having also represented the rolling elements and their contact with the raceways. The results obtained using the FEM have been correlated with the results of the new procedure.

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 Physical basis of rolling bearing vibration formation of structural

2020 ◽  
Vol 220 ◽  
pp. 01046
Author(s):  
Mikolay Hruntovich ◽  
Nadzeya Hruntovich ◽  
Aliaksei Kapanski ◽  
Larisa Markaryants ◽  
Elena Gracheva
Keyword(s):  
Rolling Bearing ◽  
Vibration Frequencies ◽  
Rolling Bearings ◽  
Bearing Defects ◽  
Rolling Elements ◽  
Different Dimensions ◽  
Bearing Vibration ◽  
Bearing Rings ◽  
Rotor Mass

The problem of increasing the reliability of detecting defects, both in new rolling bearings and the ones having already been in operation is current. The article describes the physical foundations of vibration of rolling bearings, caused by the different dimensions of the rolling elements and increased microwaves of the rings. A classification of rolling bearing defects was proposed, as well as calculation formulas for vibration frequencies corresponding to the indicated defects. It is shown that the vibration level at the overturning frequency depends on the gap size and the rotor mass. As an example, possible defects of rolling bearing No.310 were considered and their vibration frequencies were calculated. The frequency range in which defects of the rings and rolling elements appear was installed. An explanation of the reasons for the occurrence of high-frequency vibration was given. The combination of defects in the rolling elements of different dimensions and imbalance in the rotor causes the intensive development of microshells on the rolling bearing rings. Examples of experimental vibroacoustic characteristics were given to illustrate the physical processes of vibration in rolling bearings with various defects.

Effect of Pillow Block Deformation on Ball Bearing Load Distribution

2004 ◽  
Author(s):  
Patrick A. Tibbits
Keyword(s):  
Load Distribution ◽  
Variable Stiffness ◽  
Hertzian Contact ◽  
Spring Element ◽  
Bearing Life ◽  
Bearing Load ◽  
Solid Finite Elements ◽  
Program Output ◽  
Bearing Rings ◽  
Geometric Changes

Support structure deflection distorts bearing rings, redistributes loads over bearing balls, and affects bearing life. In this study, solid finite elements modeled a shaft, bearing inner ring, outer ring, and pillow block. A nonlinear spring element represented each of the bearing balls. The force-versus-deflection curve of the spring element modeled the variable stiffness of the ball/raceway Hertzian contact. The curve also incorporated the diametrical clearance of the bearing to determine if each ball contacted the raceways. Further modification of the curve compensated for the compliance of the nodes of solid elements that modeled raceways. This construct avoided computationally expensive surface-to-surface contact calculations. Program output included deflection of the pillow block and a listing of spring element forces, which characterized the ball loads. The maximum ball load decreased for a bearing installed in a pillow block, and life increased. Material or geometric changes that reduced pillow block stiffness further improved life.

scholarly journals Fatigue lifetime calculation of wind turbine blade bearings considering blade-dependent load distribution

2020 ◽  
Author(s):  
Oliver Menck ◽  
Matthias Stammler ◽  
Florian Schleich
Keyword(s):  
Load Distribution ◽  
Computational Effort ◽  
The Other ◽  
Fatigue Lifetime ◽  
Internal Load ◽  
Load Distributions ◽  
Novel Approach ◽  
Machine Elements ◽  
Bearing Loads ◽  
Yaw Bearing

Abstract. Rotating bearings are some of the most commonly employed machine elements. As such, they are well-understood and thoroughly researched pieces of technology. Fatigue lifetime calculation is internationally standardized through ISO 281 which is based on the assumption that loads act on a bearing under constant rotation. Blade bearings of wind turbines do not conform to this assumption, since their movement typically consists of small, repetitive oscillations. Moreover, their load distribution differs considerably over the bearing circumference, a load case for which ISO 281 refers to ISO 16281 and which requires detailed simulations of the bearing to be sufficiently precise. Aside from ISO 16281, the NREL DG03, a guideline for pitch and yaw bearing lifetime, lists two methods for incorporating bearing loads into the fatigue life calculation. This paper compares all three methods. Load distributions in the bearing are simulated and interpolated by means of a novel approach. The method from NREL DG03 which requires the least computational effort is shown to result in a much higher lifetime than the other two, which are based on internal load distributions of the bearing. The two latter methods are shown to produce very similar results. An adjustment is proposed for increasing the accuracy of that lifetime calculation method which requires the least computational effort in order to resemble the other two more closely.

scholarly journals Method to determine the local load cycles of a blade bearing using flexible multi-body simulation

2021 ◽  
Author(s):  
S. Leupold ◽  
R. Schelenz ◽  
G Jacobs
Keyword(s):  
Load Distribution ◽  
Structural Components ◽  
Rolling Bearings ◽  
Average Accuracy ◽  
Rolling Elements ◽  
Flexible Integration ◽  
Multi Body ◽  
Bearing Rings ◽  
Maximum Contact

AbstractConventional methods for designing rolling bearings against fatigue assume that a bearing ring is fully rotating and that the load is ideally distributed over the rolling elements. Blade bearings in wind turbines, are operated under oscillating motions and dynamic loads. The load distribution is strongly dependent on the stiffness of the bearing rings and the surrounding structural components. This has been shown in numerous studies using FEM simulations for static load cases. In this paper a method is presented that reduces the calculation effort of the deformation of the bearing rings, so that a flexible integration into an aeroelastic mbs model of a wind turbine is possible. Thereby an average accuracy of 6.5% between FEM and mbs could be achieved. The model allows the determination of time series of the global load distribution of each raceway. By data processing of the simulation results, the number of load cycles and the maximum contact pressure for individual segments of the raceways could be determined and their fatigue probability could be estimated using the linear damage hypothesis according to Palmgren-Miner.

Efficiency of application of the phase-chronometric method and neurodiagnostics for monitoring the degradation of rolling bearings during operation

2020 ◽  
pp. 43-50
Author(s):  
A.S. Komshin ◽  
K.G. Potapov ◽  
V.I. Pronyakin ◽  
A.B. Syritskii
Keyword(s):  
Life Cycle ◽  
Wavelet Analysis ◽  
Metrological Support ◽  
Rolling Bearing ◽  
Technical Condition ◽  
Measurement Information ◽  
Rolling Bearings ◽  
Vibration Diagnostics ◽  
Bearing Life ◽  
Alternative Approach

The paper presents an alternative approach to metrological support and assessment of the technical condition of rolling bearings in operation. The analysis of existing approaches, including methods of vibration diagnostics, envelope analysis, wavelet analysis, etc. Considers the possibility of applying a phase-chronometric method for support on the basis of neurodiagnostics bearing life cycle on the basis of the unified format of measurement information. The possibility of diagnosing a rolling bearing when analyzing measurement information from the shaft and separator was evaluated.

Sign in / Sign up

Export Citation Format

Share Document