Torque of Tapered Roller Bearings

1991 ◽  
Vol 113 (3) ◽  
pp. 590-597 ◽  
Author(s):  
R. S. Zhou ◽  
M. R. Hoeprich
Keyword(s):  
Film Thickness ◽  
Test Data ◽  
Roller Bearing ◽  
Elastohydrodynamic Lubrication ◽  
General Purpose ◽  
Operating Conditions ◽  
Composite Surface ◽  
Tapered Roller Bearing ◽  
Wide Range ◽  
Tapered Roller

An analytic tapered roller bearing torque model is presented along with laboratory test data. Initial results of this proposed model are favorable. An accurate general purpose torque prediction tool could be obtained by extending the concepts presented in conjunction with a more comprehensive analysis of actual bearing operating conditions. By using EHL (Elastohydrodynamic Lubrication) theory and micro-macro contact analysis, the bearing torque can be determined by predicting each torque component for each roller due to raceway rolling, raceway moments due to EHL pressure distribution, and frictional force of rib-roller end contact. The roughness effect of contact surfaces, effect of EHL film thickness parameter (the ratio of film thickness to composite surface roughness), and thermal EHL effects are also included. A bearing torque test rig, which can measure the torque of cup race, cone race, and rib separately, was built and used to provide test data. Good agreement between the experimentally measured bearing torques and the predictions of the new torque model has been obtained. This torque model will provide a greater fundamental understanding and is more versatile over a wide range of operating conditions.

Design of logarithmic crowned roller for tapered roller bearings based on the elastohydrodynamic lubrication model

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Hongyu Duan ◽  
Qingtao Yu ◽  
Zhijian Wang
Keyword(s):  
Film Thickness ◽  
Pressure Distribution ◽  
Load Distribution ◽  
Roller Bearing ◽  
Coupled Model ◽  
Elastohydrodynamic Lubrication ◽  
Content Type ◽  
Tapered Roller Bearing ◽  
Tapered Roller ◽  
Roller Profile

Purpose The purpose of this paper is to study the film-forming capacity of logarithmic crowned roller for tapered roller bearing (TRB) and to design a tapered roller profile based on an elastohydrodynamic lubrication model. Design/methodology/approach A coupled model, incorporating a quasi-static model of TRBs and an elastohydrodynamic lubrication model was developed to investigate the load distribution of TRB and to evaluate the lubrication state of tapered roller/raceway contact. Findings The model is verified with published literature results. Parametric analysis is conducted to investigate the effect of crown drop on azimuthal load distribution of the roller, film thickness and pressure distribution in the contact area. The result shows that crown drop has little influence on the azimuthal load distribution; also, the film thickness and the pressure distribution are asymmetric. When the tapered roller is designed and manufactured, the crown drop of the small end should be larger than that in the large end. Originality/value Precise roller profile design is conducive to improve the fatigue life of TRBs. Currently, most crown design methods neglect the influence of lubrication, which can lead to a non-suitable roller profile. Therefore, the present work is undertaken to optimize roller profiles based on lubrication theory.

A Starved Mixed Elastohydrodynamic Lubrication Model for the Prediction of Lubrication Performance, Friction and Flash Temperature With Arbitrary Entrainment Angle

2017 ◽  
Vol 140 (3) ◽  
Author(s):  
Wei Pu ◽  
Dong Zhu ◽  
Jiaxu Wang
Keyword(s):  
Surface Roughness ◽  
Film Thickness ◽  
Elastohydrodynamic Lubrication ◽  
Industrial Applications ◽  
Operating Conditions ◽  
Flash Temperature ◽  
Machined Surface ◽  
Lubrication Performance ◽  
Wide Range ◽  
Starved Lubrication

In this study, a modified mixed lubrication model is developed with consideration of machined surface roughness, arbitrary entraining velocity angle, starvation, and cavitation. Model validation is executed by means of comparison between the obtained numerical results and the available starved elastohydrodynamic lubrication (EHL) data found from some previous studies. A comprehensive analysis for the effect of inlet oil supply condition on starvation and cavitation, mixed EHL characteristics, friction and flash temperature in elliptical contacts is conducted in a wide range of operating conditions. In addition, the influence of roughness orientation on film thickness and friction is discussed under different starved lubrication conditions. Obtained results reveal that inlet starvation leads to an obvious reduction of average film thickness and an increase in interasperity cavitation area due to surface roughness, which results in significant increment of asperity contacts, friction, and flash temperature. Besides, the effect of entrainment angle on film thickness will be weakened if the two surfaces operate under starved lubrication condition. Furthermore, the results show that the transverse roughness may yield thicker EHL films and lower friction than the isotropic and longitudinal if starvation is taken into account. Therefore, the starved mixed EHL model can be considered as a useful engineering tool for industrial applications.

The Elastohydrodynamic Lubrication of Elliptical Point Contacts Operating in the Isoviscous Region

1995 ◽  
Vol 209 (4) ◽  
pp. 225-234 ◽  
Author(s):  
C J Hooke
Keyword(s):  
Film Thickness ◽  
Elastohydrodynamic Lubrication ◽  
Operating Conditions ◽  
Radius Ratio ◽  
Point Contacts ◽  
Reasonable Estimate ◽  
Wide Range ◽  
Minimum Film Thickness

The elastohydrodynamic lubrication of point contacts is examined and results for the minimum film thickness are presented for a wide range of radius ratios and operating conditions. The results are compared with the predictions of the appropriate regime formulae. Although these formulae give a reasonable estimate of the contact's behaviour, the actual clearances are often substantially different, particularly close to the regime boundaries. Interpolation equations for seven values of radius ratio are given and these should be sufficient to allow the minimum clearance to be estimated for most isoviscous point contacts.

Elastohydrodynamic Film Thickness in Concentrated Contacts: Part 2: Correlation of Experimental Results with Elastohydrodynamic Theory

1986 ◽  
Vol 200 (3) ◽  
pp. 219-226 ◽  
Author(s):  
R J Chittenden ◽  
D Dowson ◽  
C M Taylor
Keyword(s):  
Film Thickness ◽  
Experimental Studies ◽  
Elastohydrodynamic Lubrication ◽  
Operating Conditions ◽  
Experimental Results ◽  
Experimental Techniques ◽  
Dimensionless Parameters ◽  
Wide Range ◽  
Theoretical Predictions ◽  
Computational Procedures

The existence of a coherent film of lubricant between highly loaded machine elements has been recognized for many years. Over this period of time measurements of film thickness have gone hand in hand with theoretical analyses in the field now known as elastohydrodynamic lubrication. The experimental techniques of capacitance, electrical resistance and X-ray measurement have been supplemented by the use of optical interferometry while the analytical expressions obtained with the use of elegant simplifications have been superseded by those developed from extensive and comprehensive computational procedures. These developments in experimental techniques have yielded a substantial number of measurements of both minimum and central film thickness. Likewise, the advent of the digital computer has allowed the derivation of a large number of solutions to the problem of elastohydrodynamic lubrication of concentrated contacts. All these results, covering a wide range of geometrical conditions, are to be found in the literature, yet little attempt appears to have been made to assemble a representative set of experimental data to permit a detailed evaluation of the theoretical formulae for elliptical contacts. The second part of this paper therefore considers the correlation between a number of experimental studies covering a wide range of operating conditions and geometries, and the predictions of recent elastohydrodynamic theory. Some of the important aspects of each set of experimental results are then considered and examples are provided which illustrate the following points: 1. Good estimates of lubricant film thickness may be obtained from the theoretical expressions recently derived, even when the dimensionless parameters involved are outside the ranges considered in the derivation of the formulae. 2. The discrepancies which exist between theoretical predictions and some of the measured film thicknesses are nevertheless quite large, even when the dimensionless parameters are within their usual limits. On the whole there is good agreement between experiment and theory, while the general trend of the results indicates that theoretical predictions may underestimate the minimum film thickness by about 10 per cent and the central film thickness by about 25 per cent. This measure of agreement is quite remarkable when the extreme difficulty of interpreting the magnitudes of effective and very thin mean film thicknesses between machined components in various forms of experimental equipment is considered.

Simulation and Experimental Validation of Tapered Roller Bearing Vibration Induced by Geometrical Imperfection on Cup Raceway

2014 ◽  
Author(s):  
Desheng Li ◽  
Young Sup Kang
Keyword(s):  
Test Data ◽  
Roller Bearing ◽  
Three Dimensional ◽  
Surface Profile ◽  
Elastohydrodynamic Lubrication ◽  
Hertzian Contact ◽  
Test Machine ◽  
Vibration Model ◽  
Tapered Roller ◽  
Bearing Vibration

A three dimensional non-linear vibration model of tapered roller bearings was developed based on an in-house dynamic bearing model (DBM), which simulates the motion of bearing components and their interactions using Hertzian contact, traction, and hydrodynamic/ elastohydrodynamic lubrication models. The vibration model can simulate bearings with distributed and localized geometrical imperfections on their cup raceways, cone raceways, and roller bodies. This paper focuses on the influence of localized cup raceway imperfections on bearing vibration. Three levels of localized defects were intentionally created on cup raceways and quantified using a surface profile gauge. The quantified defects on actual test bearings were used as inputs to the vibration model. The corresponding test bearings were evaluated with a high-precision bearing vibration test machine. Two different bearing designs were used in the study. The simulation and test data were analyzed and compared, and it was found that the simulation results agreed well with the test data.

Investigation on the Lubrication Performances and Thermal Characteristics of the Tapered Roller Bearing

2017 ◽  
Author(s):  
Yunjia Zhang ◽  
Dengfang Ruan
Keyword(s):  
Heat Transfer ◽  
Roller Bearing ◽  
Thermal Characteristics ◽  
Simulation Models ◽  
Operating Conditions ◽  
Dual Clutch Transmission ◽  
Ansys Fluent ◽  
Tapered Roller Bearing ◽  
Tapered Roller ◽  
Transfer Properties

In this paper, the tapered roller bearing supported on the output shaft of the dual clutch transmission was studied. During the operating process of the DCT (Dual Clutch Transmission) gearbox, the heat generation of the bearing is very large due to the large operating load and high operating speed, which will easily result in bearing failure, such as pitting and abrasion, so it is necessary to investigate the lubrication performances and thermal characteristics of the tapered roller bearing. The simulation models considering or not considering the roller’s spinning (the rollers rotating on their own axles) were established based on Ansys Fluent software. The influences of the roller’s spinning on the lubrication performances of the bearing were analyzed. Furthermore, the transit heat transfer properties of the bearing were simulated and analyzed. The roller’s spinning and transit heat boundary specification were realized by using UDF (user-defined functions). At the same time, the lubrication performances and heat transfer properties of the bearing with different operating conditions are presented and analyzed.

Numerical Solution of Mixed Thermal Elastohydrodynamic Lubrication in Point Contacts With Three-Dimensional Surface Roughness

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Xiaopeng Wang ◽  
Yuchuan Liu ◽  
Dong Zhu
Keyword(s):  
Surface Roughness ◽  
Film Thickness ◽  
Three Dimensional ◽  
Point Contact ◽  
Elastohydrodynamic Lubrication ◽  
Lubricant Film ◽  
Operating Conditions ◽  
Thickness Variation ◽  
Wide Range ◽  
Film Lubrication

Elastohydrodynamic lubrication (EHL) is a common mode of fluid-film lubrication in which many machine elements operate. Its thermal behavior is an important concern especially for components working under extreme conditions such as high speeds, heavy loads, and surfaces with significant roughness. Previous thermal EHL (TEHL) studies focused only on the cases with smooth surfaces under the full-film lubrication condition. The present study intends to develop a more realistic unified TEHL model for point contact problems that is capable of simulating the entire transition of lubrication status from the full-film and mixed lubrication all the way down to boundary lubrication with real machined roughness. The model consists of the generalized Reynolds equation, elasticity equation, film thickness equation, and those for lubricant rheology in combination with the energy equation for the lubricant film and the surface temperature equations. The solution algorithms based on the improved semi-system approach have demonstrated a good ability to achieve stable solutions with fast convergence under severe operating conditions. Lubricant film thickness variation and temperature rises in the lubricant film and on the surfaces during the entire transition have been investigated. It appears that this model can be used to predict mixed TEHL characteristics in a wide range of operating conditions with or without three-dimensional (3D) surface roughness involved. Therefore, it can be employed as a useful tool in engineering analyses.

Optimization of operating conditions for a double-row tapered roller bearing

2015 ◽  
Vol 12 (3) ◽  
pp. 353-373 ◽  
Author(s):  
Ruben Lostado ◽  
Ruben Escribano García ◽  
Roberto Fernandez Martinez
Keyword(s):  
Roller Bearing ◽  
Operating Conditions ◽  
Double Row ◽  
Tapered Roller Bearing ◽  
Tapered Roller

scholarly journals Load Calculation and Design of Roller Crowning of Truck Hub Bearing

2015 ◽  
Vol 9 (1) ◽  
pp. 106-110 ◽  
Author(s):  
Xintao Xia ◽  
Shujing Dong ◽  
Liming Sun ◽  
Tianju Chen
Keyword(s):  
Roller Bearing ◽  
Operating Conditions ◽  
Double Row ◽  
Element Analysis ◽  
Tapered Roller Bearing ◽  
Profile Modification ◽  
Tapered Roller ◽  
Tapered Roller Bearings ◽  
Roller Profile ◽  
Control Equation

Double-row tapered roller bearing 353112 is used in trucks, and the external load and pressure distribution of the bearing are calculated combining with the specific operating conditions. Tapered roller bearings typically employ roller profile modification to equalize the load distribution, minimizing the stress concentration at the roller ends. Doing FEA (finite element analysis) on the contact stress with the changing roller crowning between roller and races, the appropriate roller profile and the crown drop of roller can be achieved. Finally the best control equation of roller crowning is obtained. It has important guiding significance for the improvement of roller crowning design of truck hub bearings.

On the Stribeck Curves for Lubricated Counterformal Contacts of Rough Surfaces

2015 ◽  
Vol 137 (2) ◽  
Author(s):  
Dong Zhu ◽  
Jiaxu Wang ◽  
Q. Jane Wang
Keyword(s):  
Film Thickness ◽  
Numerical Solutions ◽  
Rough Surfaces ◽  
Elastohydrodynamic Lubrication ◽  
Real Data ◽  
Operating Conditions ◽  
Stribeck Curve ◽  
Flash Temperature ◽  
Wide Range ◽  
Stribeck Curves

The “Stribeck curve” is a well-known concept, describing the frictional behavior of a lubricated interface during the transition from boundary and mixed lubrication up to full-film hydrodynamic/elastohydrodynamic lubrication. It can be found in nearly every tribology textbook/handbook and many articles and technical papers. However, the majority of the published Stribeck curves are only conceptual without real data from either experiments or numerical solutions. The limited number of published ones with real data is often incomplete, covering only a portion of the entire transition. This is because generating a complete Stribeck curve requires experimental or numerical results in an extremely wide range of operating conditions, which has been a great challenge. Also, numerically calculating a Stribeck curve requires a unified model with robust algorithms that is capable of handling the entire spectrum of lubrication status. In the present study, numerical solutions in counterformal contacts of rough surfaces are obtained by using the unified deterministic mixed elastohydrodynamic lubrication (EHL) model recently developed. Stribeck curves are plotted in a wide range of speed and lubricant film thickness based on the simulation results with various types of contact geometry using machined rough surfaces of different orientations. Surface flash temperature is also analyzed during the friction calculation considering the mutual dependence between friction and interfacial temperature. Obtained results show that in lubricated concentrated contacts, friction continuously decreases as speed and film thickness increase even in the full-film regime until extremely high speeds are reached. This is mainly due to the reduction of lubricant limiting shear stress caused by flash temperature rise. The results also reveal that contact ellipticity and roughness orientation have limited influence on frictional behaviors, especially in the full-film and boundary lubrication regimes.

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