Calculation of the necessary level of external radial load for inner ring support on q rolling elements in a radial bearing with internal radial clearance

2012 ◽  
Vol 60 (1) ◽  
pp. 23-33 ◽  
Author(s):  
Radoslav Tomović
Keyword(s):  
Radial Clearance ◽  
Radial Load ◽  
Radial Bearing ◽  
Ring Support ◽  
Rolling Elements

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.

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.

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 Fatigue of Cylindrical Roller Bearing in Printing Press

2013 ◽  
Vol 312 ◽  
pp. 25-28
Author(s):  
Ji Mei Wu ◽  
Yan Chen ◽  
Bo Gao ◽  
Tuan Yong Yi
Keyword(s):  
Fatigue Life ◽  
Roller Bearing ◽  
Flow Chart ◽  
Printing Press ◽  
Radial Clearance ◽  
Radial Load ◽  
Double Row ◽  
Rotating Speed ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller

By means of considering improved Lundberg-Palmgren (L-P) fatigue life theory and rollers and other comprehensive factors, a model of fatigue life is setup for eccentric double row cylindrical roller bearing under rotation. On this basis, the calculation flow chart is given and the fatigue life is calculated. Then come to the conclusions that the fatigue life of bearing is influenced by radial load, rotating speed, radial clearance.

Rolling Element Bearing Non-Linearity Effects

2000 ◽  
Author(s):  
N. S. Feng ◽  
E. J. Hahn
Keyword(s):  
Equations Of Motion ◽  
Rolling Element Bearing ◽  
Radial Clearance ◽  
Rotor Systems ◽  
Bearing Life ◽  
Rolling Element ◽  
Bearing Load ◽  
Rolling Elements ◽  
Element Bearing ◽  
Negative Clearance

Non-linearity effects in rolling element bearings arise from two sources, viz. the Hertzian force deformation relationship and the presence of clearance between the rolling elements and the bearing races. Assuming that centrifugal effects may be neglected and that the presence of axial preload is appropriately reflected in a corresponding change in the radial clearance, this paper analyses a simple test rig to illustrate that non-linear phenomena such as synchronous multistable and nonsynchronous motions are possible in simple rigid and flexible rotor systems subjected to unbalance excitation. The equations of motion of the rotor bearing system were solved by transient analysis using fourth order Runge Kutta. Of particular interest is the effect of clearance, governed in practice by bearing specification and the amount of preload, on the vibration behaviour of rotors supported by ball bearings and on the bearing load. It is shown that in the presence of positive clearance, there exists an unbalance excitation range during which the bearing is momentarily not transmitting force owing to contact loss, resulting in rolling element raceway impact with potentially relatively high bearing forces; and indicating that for long bearing life, operation with positive clearance should be avoided in the presence of such unbalance loading. Once the unbalance excitation is high enough to avoid such contact loss, it is the bearings with zero or negative clearance which produce maximum bearing forces.

Effect of Geometric Error of Inner Raceway on Motion of Cylindrical Roller Bearings Under Radial Load

2018 ◽  
Author(s):  
Li Jishun ◽  
Yu Yongjian ◽  
Xue Yujun ◽  
Zhou Yuankun ◽  
Guan Zhiqiang
Keyword(s):  
Roller Bearing ◽  
Geometric Error ◽  
Radial Clearance ◽  
Radial Load ◽  
Compatibility Equation ◽  
Motion Error ◽  
Roundness Error ◽  
Cylindrical Roller Bearing ◽  
Geometric Compatibility ◽  
Cylindrical Roller

The motion error of bearing depends highly on the geometric profile of bearing components. Therefore, it is crucial to establish a correlation between the geometric error of bearing components and the motion error of an assembled bearing, which is required for designing and manufacturing bearings with high accuracy of motion. In this paper, authors derived a geometric compatibility equation for cylindrical roller bearing considering the geometric error of bearing inner raceway. Based on the load balance and the geometric compatibility derived, a mathematical model of motion accuracy is established, and the model is also validated. The effect of geometric error such as the amplitude of roundness error and dimension error of bearing inner raceway, and radial clearance on the bearing motion error is investigated. Results show that the motion error of the bearing increases with the amplitude of the roundness error of inner raceway, and reduces with the increase of radial load. The results indicated that the motion accuracy can be improved by controlling the distribution of machining tolerance of bearing components.

scholarly journals An Approach to Calculating Casing Bearing Capacity with Parabolic Deformation Characteristics Under Local Radial Loading

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1769
Author(s):  
Wanchun Zhao ◽  
Jing Ge ◽  
Pathegama Gamage Ranjith ◽  
Tingting Wang ◽  
Lijie Han
Keyword(s):  
Bearing Capacity ◽  
Radial Deformation ◽  
Deformation Characteristics ◽  
Radial Load ◽  
External Work ◽  
Radial Bearing ◽  
Study Results ◽  
Casing Deformation ◽  
Radial Loading ◽  
The Impact

In the process of waterflooding technology in the Jilin oilfield, local radial compressive stress caused by rock deformation results in local casing collapse. According to statistics regarding casing-deformation characteristics, a certain number of these characteristics are approximately parabola-shaped at the radial-deformation bottom, and the boundary of the whole deformation area is approximately symmetrical and double-parabola-shaped. The main work of this article focused on occurrences of such casing deformation. Assuming that, in the process of casing deformation, external work is totally converted into energy consumption due to the deformation, the variation regularity of bearing capacity under local radial load was obtained. In the Qing-1 stratum of the Jilin oilfield, by selecting casing with radial collapse deformation parameters of 41/2″J55, 51/2″J55, 41/2″N80, and 51/2″N80, radial bearing capacity was calculated. Study results showed that the casing bearing-capacity value was reduced by 39.69% compared with the current API 5C3 standard when under the action of a local radial load. The casing collapsed due to the impact of local radial loads produced by mudstone creep. A series of relationships between radial bearing strength and casing parameters were also obtained. The research results are of significant academic value for the compilation of casing design codes or standards under local radial loading.

scholarly journals Experimental Stability Studies of the Herringbone-Grooved Gas-Lubricated Journal Bearing

1969 ◽  
Vol 91 (1) ◽  
pp. 52-57 ◽  
Author(s):  
Robert E. Cunningham ◽  
David P. Fleming ◽  
William J. Anderson
Keyword(s):  
Journal Bearing ◽  
Experimental Studies ◽  
Ambient Air ◽  
Fair Agreement ◽  
Radial Clearance ◽  
Radial Load ◽  
Test Results ◽  
Stability Studies ◽  
Theory And Experiment

Experimental studies were conducted on six rotors, 1 1/2 in. dia by 12 1/4 in. long operating in ambient air to high compressibility numbers. Herringbone-groove geometries and clearances were varied to determine their effect on half-frequency whirl (HFW). All rotors were operated vertically and without any applied radial load. Results show that half-frequency-whirl onset is very sensitive to radial clearance. Limited test results indicate that a fully grooved bearing is more stable than a partially grooved one, other parameters being equal. Generally fair agreement between theory and experiment was achieved for predicting HFW onset speeds.

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