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 Correction of Radial Load Distribution Integral for Radial Bearings

2020 ◽  
Author(s):  
Yu Hou ◽  
Yi Yin ◽  
Xi Wang
Keyword(s):  
External Load ◽  
Load Distribution ◽  
Integral Method ◽  
Load Transfer ◽  
Radial Clearance ◽  
Radial Load ◽  
Numerical Examples ◽  
Small Load ◽  
Rolling Elements ◽  
Three Stages

Abstract The radial load distribution integral is corrected for radial bearings. The error of Harris integral method for calculating the radial load distribution is analysed. The error is found absolutely caused by the inaccurate values of the radial load distribution integral given by Harris. Based on the extent of the load zone, the radial load distribution integral is corrected by three stages. The corrected radial load distribution integral is capable of calculating the load distribution of a bearing with a small load zone caused by a light external load or a great radial clearance. The corrected radial load distribution integral is found affected by the number of rolling elements. According to the variation of the number of rolling elements participating in the radial load transfer, the corrected radial load distribution integral can be divided into different phases. Some specific numerical examples are shown to illustrate the performance of the corrected radial load distribution integral. The comparison between the results obtained from the corrected radial load distribution integral and Harris integral shows the higher accuracy and superiority of the corrected radial load distribution integral.

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.

scholarly journals Vibration response of defect-ball-defect of rolling bearing with compound defects on both inner and outer races

2021 ◽  
Vol 1207 (1) ◽  
pp. 012006
Author(s):  
Wei Luo ◽  
Changfeng Yan ◽  
Junbao Yang ◽  
Yaofeng Liu ◽  
Lixiao Wu
Keyword(s):  
Rolling Bearing ◽  
Vibration Response ◽  
Radial Clearance ◽  
Rolling Bearings ◽  
Outer Race ◽  
Response Characteristics ◽  
Bearing Fault Diagnosis ◽  
Theoretical Criterion ◽  
Vibration Model ◽  
Rolling Elements

Abstract Aiming at the problem that the existing compound defects model of rolling bearings under radial load is difficult to reflect the actual contact between rolling elements and defects. A new model is proposed to accurately reflect the simultaneous or sequential contact between inner and outer race defects and rolling elements. Considering the coupled excitation between shaft and bearing and pedestal, time-varying displacement excitation, and radial clearance, a four degree-of-freedom vibration model of rolling bearing with compound faults on both inner and outer races is built. The vibration equations are calculated by the method of numerical way, and the model is verified by experiment. The vibration response characteristics of the Defect-Ball-Defect model are studied, which renders a theoretical criterion for bearing fault diagnosis.

scholarly journals A Simplified Mathematical Model for the Analysis of Varying Compliance Vibrations of a Rolling Bearing

2020 ◽  
Vol 10 (2) ◽  
pp. 670 ◽  
Author(s):  
Radoslav Tomović
Keyword(s):  
Mathematical Model ◽  
Parametric Analysis ◽  
Rolling Bearing ◽  
Influential Factors ◽  
Radial Clearance ◽  
Radial Load ◽  
Simplified Approach ◽  
Rolling Element ◽  
Rolling Elements ◽  
Varying Compliance

In this paper, a simplified approach in the analysis of the varying compliance vibrations of a rolling bearing is presented. This approach analyses the generation of vibrations in relation to two boundary positions of the inner ring support on an even and an odd number of the rolling element of a bearing. In this paper, a mathematical model for the calculation of amplitude and frequency of vibrations of a rigid rotor in a rolling bearing is presented. The model is characterized by a big simplicity which makes it very convenient for a practical application. Based on the presented mathematical model a parametric analysis of the influence of the internal radial clearance, external radial load and the total number of rolling elements on the varying compliance vibrations of rolling bearing was conducted. These parameters are the most influential factors for generating varying compliance vibrations. The results of the parametric analysis demonstrate that with the proper choice of the size of the internal radial clearance and external radial load, the level of the varying compliance vibrations in a rolling bearing can be theoretically reduced to zero. This result opposes the opinion that varying compliance vibrations of rolling bearing cannot be avoided, even for geometrically ideally produced bearing.

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.

Traction Behavior of Some Lubricants Used for Rolling Bearings in Spacecraft Applications: Experiments and Thermal Model Based on Primary Laboratory Data

2001 ◽  
Vol 124 (1) ◽  
pp. 72-81 ◽  
Author(s):  
Daniel Ne´lias ◽  
Eric Legrand ◽  
Philippe Vergne ◽  
Jean-Bernard Mondier
Keyword(s):  
Thermal Model ◽  
Laboratory Data ◽  
Rolling Bearing ◽  
Operating Conditions ◽  
Model Parameters ◽  
Rolling Bearings ◽  
Traction Coefficient ◽  
Shear Heating ◽  
Rheological Experiments

Three synthetic oils used in spacecraft mechanisms (Pennzane SHF X2000, Nye 186 A, and Fomblin Z25) have been studied. Rheological tests were performed in order to characterize the behavior of each fluid versus pressure, temperature and shear rate. That includes the determination of the WLF viscosity model parameters. Tribological tests were carried out to measure the traction coefficient for operating conditions representative of spacecraft applications. Experimental results were compared with theoretical ones obtained using a non-newtonian thermal model. The modeling of traction in EHL contact is based on the Johnson and Tevaarwerk’s model modified to account for the shear heating of the fluid. The variations of the lubricant thermal conductivity with respect to temperature and pressure are also considered. In this model, input data comes directly from rheological experiments or are derived from other measurements through physical relationships. These rheological and tribological characterizations are essential to better describe the behavior of a lubricated rolling bearing.

Hysteretic Resonances and Intermittency Chaos in Ball Bearings

2018 ◽  
Author(s):  
Zhiyong Zhang ◽  
Xiaoting Rui ◽  
Yushu Chen ◽  
Wenkai Dong ◽  
Lei Li
Keyword(s):  
Ball Bearing ◽  
Harmonic Balance Method ◽  
Rolling Bearing ◽  
Hertzian Contact ◽  
Ball Bearings ◽  
Rolling Bearings ◽  
Rotor Systems ◽  
Revolute Joints ◽  
Rolling Elements ◽  
Varying Compliance

Ball bearings are essential parts of mechanical systems to support the rotors or constitute the revolute joints. The time-varying compliance (VC), bearing clearance and the Hertzian contact between the rolling elements and raceways are three fundamental nonlinear factors in a ball bearing, hence the ball bearing can be considered as a nonlinear system. The hysteresis and jumps induced by the nonlinearities of rolling bearings are typical phenomena of nonlinear vibrations in the rolling bearing-rotor systems. And the corresponding hysteretic impacts have direct effects on the cleavage derivative and fatigue life of the system components. Therefore, the behaviors of hysteresis and jumps are given full attentions and continued studies in the theoretical and engineering fields. Besides, many researchers have done a lot of calculations to depict the various characteristics of bifurcations and chaos in the rolling bearings and their rotor systems, but few researches have been addressed on the inherent mechanism of the typical intermittency vibrations in rolling bearings. With the aid of the HB-AFT (the harmonic balance method and the alternating frequency/time domain technique) method and Floquet theory, this paper will investigate deeply the resonant hysteresis and intermittency chaos in ball bearings.

Characteristics and Mechanical Properties of Rolling-Element Bearings

2016 ◽  
Vol 8 (3) ◽  
Author(s):  
Lv Haiting
Keyword(s):  
Mechanical Properties ◽  
Load Distribution ◽  
Large Scale ◽  
Roller Bearing ◽  
Rolling Bearing ◽  
Fe Model ◽  
Rolling Bearings ◽  
Angle Variation ◽  
Supporting Structure ◽  
The Impact

Large rolling bearings are mainly used in occasions of low speed and heavy load due to its desirable properties such as large-scale structure and high bearing capacity. Currently, the research emphases of large rolling bearings are focussed on the load distribution, load carrying capacity, fatigue life and structure optimization. Bearings used in heavy vehicles belong to large bearings, whose reliability is also very important. In this paper, the characteristics of the structures of four point angular contact ball bearings and three row cylindrical roller bearing are analyzed. Finite element (FE) model is used to simulate the load distribution and angle variation in the actual working process of a large rolling bearing. In order to analyze the impact of the constraints, the stiffness and the local hard point of the supporting structure on the mechanical properties of large rolling bearings, a series of simplified FE models of large rolling bearing with different constraints and supporting structure has been carried out.

scholarly journals Radial internal clearance analysis in ball bearings

2021 ◽  
Vol 23 (1) ◽  
pp. 42-54
Author(s):  
Bartłomiej Ambrożkiewicz ◽  
Arkadiusz Syta ◽  
Nicolas Meier ◽  
Grzegorz Litak ◽  
Anthimos Georgiadis
Keyword(s):  
Rolling Bearing ◽  
Radial Clearance ◽  
Ball Bearings ◽  
Continuous Wavelet ◽  
Vibration Acceleration ◽  
Condition Indicators ◽  
Novel Approach ◽  
Rotary Machines ◽  
Rolling Elements ◽  
Dynamics Method

Radial internal clearance (RIC) is one of the most important parameters influencing on rolling bearing exploitation in mechanical systems. Lifetime of rotary machines strongly depends on a condition of applied rolling elements, thus a study on applied clearance is very important in terms of maintenance and reliability. This paper proposes, a novel approach of studying RIC, based on a nonlinear dynamics method called recurrences. The results are confronted with standard analyses, i.e. statistical condition indicators, Fast Fourier Transform and Continuous Wavelet Transform. The application of the mentioned methods allowed us to find the optimal radial clearance for operating bearings. To ensure precise measurements of the clearance, an automated setup for RIC measurements is applied and next mounted in a plummer block and tested to finally measure vibration acceleration. The proposed methods are useful for a condition monitoring and lifetime prediction of bearings or bearing-based systems in which a proper value of radial clearance is crucial.

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