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.

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.

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.

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 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.

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.

Analysis of Rolling Bearings With Reduced Numbers of Balls or Rollers

2004 ◽  
Vol 126 (2) ◽  
pp. 407-411 ◽  
Author(s):  
John H. Rumbarger
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Computer Software ◽  
Rolling Bearings ◽  
Element Analysis ◽  
Rolling Elements ◽  
Computer Printout ◽  
Bearing Rings ◽  
Bearing Analysis ◽  
Selection Of

A method is presented to allow the computer analysis of rolling bearings with reduced numbers of balls or rollers with no loss of accuracy. There are three advantages with the ability to model the bearings with less than the actual numbers of balls or rollers: (1) The method allows for the analysis of bearings which have more balls or rollers than allowed by the dimensioning of the computer software; (2) The method allows for the selection of a model number of nodes or rolling elements which are equally spaced and correspond to the number of nodes of a finite element analysis of the bearing rings and mounting structure; and (3) The method can reduce the computer printout for the bearing analysis.

A unified and simplified treatment of the non-linear equilibrium problem of double-row rolling bearings. Part 1: Rolling bearing model

2003 ◽  
Vol 217 (3) ◽  
pp. 205-212 ◽  
Author(s):  
I Bercea ◽  
D Nélias ◽  
G Cavallaro
Keyword(s):  
Roller Bearing ◽  
Rolling Bearing ◽  
Rolling Bearings ◽  
Angular Contact Ball Bearing ◽  
Double Row ◽  
Tapered Roller Bearing ◽  
Tapered Roller ◽  
Cylindrical Roller Bearing ◽  
Bearing Rings

To increase the rigidity of bearings-shaft systems, the shaft is often supported by a series of double-row rolling bearings. Little work on multiple-row rolling bearings has been published. A comprehensive model is proposed which permits the determination of the internal interactions. The total elastic deflection between bearing rings is described using a vector-and-matrix method. A variety of double-row rolling bearing types are analysed, such as tapered roller bearing, cylindrical roller bearing, spherical roller bearing, self-aligning ball bearings and angular contact ball bearing. The basic internal geometry (including the internal clearance) and the effect of the initial preload (in term of the initial axial compression) are considered.

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>

Electric impedance of rolling bearings - Consideration of unloaded rolling elements

2021 ◽  
Vol 158 ◽  
pp. 106927
Author(s):  
T. Schirra ◽  
G. Martin ◽  
S. Puchtler ◽  
E. Kirchner
Keyword(s):  
Electric Impedance ◽  
Rolling Bearings ◽  
Rolling Elements

scholarly journals Rapid Determination of Ethylene Oxide and 75 VOCs in Ambient Air with Canister Sampling and Associated Growth Issues

Separations ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 35
Author(s):  
Jason Hoisington ◽  
Jason S. Herrington
Keyword(s):  
Ethylene Oxide ◽  
Rapid Determination ◽  
Complex Mixture ◽  
Ambient Air ◽  
Gas Chromatography Mass Spectrometry ◽  
Average Accuracy ◽  
Relative Standard ◽  
Wide Range ◽  
Us Epa

A canister-based sampling method along with preconcentrator-Gas chromatography-Mass Spectrometry (GC-MS) analysis was applied to ethylene oxide (EtO or EO) and 75 other volatile organic compounds (VOCs) in ambient air. Ambient air can contain a large variety of VOCs, and thorough analysis requires non-discriminatory sampling and a chromatographic method capable of resolving a complex mixture. Canister collection of whole air samples allows for the collection of a wide range of volatile compounds, while the simultaneous analysis of ethylene oxide and other VOCs allows for faster throughput than separate methods. The method presented is based on US EPA Method TO-15A and allows for the detection of EtO from 18 to 2500 pptv. The method has an average accuracy of 104% and precision of 13% relative standard deviation (RSD), with an instrument run time of 32 min. In addition, a link between canister cleanliness and ethylene oxide growth is observed, and potential mechanisms and cleaning strategies are addressed.

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