The Radial and Axial Stiffnesses of Tapered Roller Bearings Under Combined Load

1996 ◽  
Vol 118 (1) ◽  
pp. 257-263 ◽  
Author(s):  
H. Zantopulos

Equations and their derivations for finding the radial and axial stiffnesses of a single-row tapered roller bearing, assuming a rigid shaft and housing, are given for any case of combined radial and axial loads. This method is extended to include the two-row bearing under certain conditions. Also presented are tables to facilitate these calculations.

Author(s):  
Michael N. Kotzalas

The original two-parameter Weibull distribution used for rolling element bearing fatigue tends to greatly underestimate life at high levels of reliability. This fact has been proven for through hardened ball, cylindrical and spherical roller bearings, as well as linear ball bearings, by other researchers. However, to date this has not been done with tapered roller bearings (TRB) or case carburized materials, and as such this study was conducted. First, the three-parameter Weibull distribution was utilized to create a mathematical model, and statistical data analysis methods were put into place. This algorithm was then investigated as to its ability to discern the shape of the reliability distribution using known, numerically generated, data sets for two and three-parameter Weibull distributions. After validation, an experimental data set of 9702 TRB’s, 98% of which were case carburized, was collected. Using the developed algorithm on this data set, the overall RMS error was reduced from 26.0% for the standard, two-parameter to 12.2% for the three-parameter Wiebull distribution. Also, the error at 99.9% reliability was reduced from 95.8% to 37%. However, as the results within varied from previously published values at high reliabilities, there is likely a difference in the underlying population and/or dependency on the statistical and mathematical methods utilized. Therefore, more investigation should be conducted in this area to identify the underlying variables and their effects on the results.


Author(s):  
Parbant Singh ◽  
S.P. Harsha

Freight trains run under high service loads during consignment loading and operation so tapered roller bearings are ideally suited to wheel bearing applications. The tapered roller bearings used in the railway industry are of a standard design fixed by the American Association of Railroads regulations. Nowadays rail industry improves the train operating speeds, which means that failure of a bearing will result into a derailment, affecting human lives, network disruption, and damage to the railroad, unplanned maintenance costs, and generating fear in general public about rail transport. So the rail industry has focused on the improvement in maintenance work and improvement in component design. This paper discusses the results of finite element analysis and model analysis of Cartridge Tapered Roller bearing (CTRB). Solid modelling of CTRB has been done using solid works. The CTRB is then discretized using ANSYS software and 3D hexahedral solid elements are used to mesh the components. The effect of vibration modes on the dynamic behaviour and stability of wagon is described. Frequencies up to a range of 100 Hz are considered for mode shapes.


Author(s):  
J. A. Karloff ◽  
W. N. Weins ◽  
R. C. Arnold

Abstract One of the important components of a tapered roller bearing is the cage. The main function of the cage during operation is to maintain roller spacing. Although being one of the more complicated parts of a tapered roller bearing, historically, very little specific engineering has been published to provide a design basis for the tapered roller bearing cage. This work analyzed specifically, the cages from tapered roller bearings as used in the railway industry. As the load carrying requirements for railcars have increased, the size of bearing has also increased. Although cage dimensions have increased with bearing size, little specific engineering has been published to document the effect the change in size has on the durability of the larger cages. Testing was conducted to determine the amount of stress induced on the cage due to the vibration environment of a tapered roller bearing used in rail service. Cages evaluated were steel cages from 6 ½ × 12 and 7 × 12 tapered roller bearings and a plastic cage from a 6 ½ × 12 bearing. The natural frequencies of the cages were determined and then compared to the exciting frequencies of the bearings. Vibrations, internal and external to the bearing were measured at various simulated train speeds. The magnitude and frequencies of these excitation vibrations were input into the finite element modeling software, ALGOR®, to find the response of the cage. It was found that the stresses generated in the small end cage pocket of larger 7 × 12 steel cages were as much as twice that of the 6 ½ × 12 steel cages. The stress generated at the pocket of the 6 ½ × 12 plastic cage was smaller than the 6 ½ × 12 steel cage.


2012 ◽  
Vol 217-219 ◽  
pp. 2328-2331 ◽  
Author(s):  
Abiodun Falodi ◽  
Yong K. Chen ◽  
Martin Caspall ◽  
Brian Earthrowl ◽  
David Dell

Roller skew in roller bearings can cause heat generation and reduce bearing life. Therefore, design to minimise its occurrence is essential in bearing development. This study investigated the roller skew of a double row tapered roller bearing under various running conditions. A new system of measurement using two differential variable reluctance transducers (DVRT) was developed. It is evident that the roller skew of the double row tapered roller bearing can be measured. The shaft rotational speed has a significant effect on roller skew but the radial load has little effect.


1981 ◽  
Vol 103 (1) ◽  
pp. 13-20 ◽  
Author(s):  
R. J. Parker ◽  
S. I. Pinel ◽  
H. R. Signer

The performance of 120.65-mm (4.75-in.) bore high-speed design tapered roller bearings was investigated at shaft speeds of 20,000 rpm (2.4 million DN) under combined thrust and radial load. The test bearings design was computer optimized for high-speed operation. Temperature distribution and bearing heat generation were determined as a function of shaft speed, radial and thrust loads, lubricant flow rates, and lubricant inlet temperature. The high-speed design tapered roller bearing operated successfully at shaft speeds up to 20,000 rpm under heavy thrust and radial loads. Bearing temperatures and heat generation with the high-speed design bearing were significantly less than those of a modified standard bearing tested previously. Cup cooling was effective in decreasing the high cup temperatures to levels equal to the cone temperature.


Author(s):  
Amy Gonzalez ◽  
Constantine Tarawneh ◽  
Ping Hu ◽  
Joseph A. Turner ◽  
Brent M. Wilson

Fatigue spall initiation is one of the major modes of premature bearing failure. The spall initiation is often exacerbated by the presence of impurities in the near-surface region (∼400 μm) of the bearing raceways. Once a spall initiates, it can propagate rapidly, leading to abnormal bearing operation and possible catastrophic failure if not detected early. Testing performed at the University of Texas-Pan American (UTPA) has focused on ultrasonically scanned tapered roller bearings found to have inclusion content within 400 μm of the surface of the raceways. These bearings undergo accelerated service life tests in which spall initiation is detected and tracked over time while documenting spall growth. The work presented here provides several study cases that document the spall initiation and propagation on ultrasonically scanned tapered roller bearing components. Results show that spalls generally initiate on locations corresponding to sites of subsurface inclusions, and they grow many times their original size within relatively short operating periods. The study also shows that spalls tend to initiate and propagate at a faster rate on bearing cups (outer rings) than on cones (inner rings).


Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1371 ◽  
Author(s):  
Francisco Brosed ◽  
A. Zaera ◽  
Emilio Padilla ◽  
Fernando Cebrián ◽  
Juan Aguilar

Tapered roller bearings can accommodate high radial loads as well as high axial loads. The manufacturing process consists of machining processes for ring and component assembly. In this contribution, the parameters of influence on the measurement procedure were studied. These parameters of influence were classified as environmental, process, and machine parameters. The main objective of this work was to optimize the process using real-time measurements, which required the study of the influence of several parameters on the measurement uncertainty and how to correct their effects.


1974 ◽  
Vol 188 (1) ◽  
pp. 461-469 ◽  
Author(s):  
R. H. Leaver ◽  
R. S. Sayles ◽  
T. R. Thomas

Measurements of friction torque in a tapered roller bearing are made over a range of axial loads at low rotational speeds. Under these conditions considerable metallic contact between surface asperities occurs. Experimental and theoretical values of no-contact time are compared. The usually adopted ratio of calculated film thickness to gross surface r.m.s. value is shown to be a less meaningful measure of the quality of lubrication than one based on the r.m.s. after filtering out contributions due to asperities of wavelength greater than twice the Hertzian width. An analysis of the statistical properties of worn and unworn surfaces is made. Digital filtering of the power spectrum reveals differences that are not apparent in the unfiltered data. Asperities of long and very short wavelengths, compared with the Hertzian width, are shown to be little affected during running-in whilst those of intermediate size are removed.


1976 ◽  
Vol 98 (4) ◽  
pp. 564-572 ◽  
Author(s):  
J. Y. Liu

This paper presents an analytical study of the load distribution in a tapered roller bearing operating at a high speed and under combined loading. The friction forces at the rolling contacts and the cage forces are not considered. A numerical example showing, among other things, the effects of misalignment and speed on the bearing fatigue life and the sliding velocity at the flange contact is given.


Author(s):  
Van-Canh Tong ◽  
Seong-Wook Hong

Angular misalignment, defined as the tilted angle between the outer ring and inner ring, is unavoidable in most applications of tapered roller bearings (TBRs) due to many potential causes such as shaft deflection, initial mounting error, bearing geometry inaccuracy, etc. The occurrence of TRB misalignment introduces considerable changes into the contact load and the pressure between rolling elements and the raceways and, thus, greatly influences the bearing life. However, few research results are available on the effects of angular misalignment in TRBs. This paper presents the fatigue life analysis for TRBs with consideration for angular misalignment effects. To this end, a mathematical TRB model is developed to provide a comprehensive fatigue life analysis for TRBs subjected to angular misalignment. The presented model is verified by comparing the estimated fatigue lives under several loading conditions with those from a reference program. Then, the effects of angular misalignment on the fatigue life of TRBs are evaluated systematically. The simulation results show the importance of TRB alignment for the investigated TRB by demonstrating that small amount of angular misalignment leads to a substantial reduction in the fatigue life of the TRB regardless of loading conditions. The results address the necessity of misalignment effects analysis for TRBs.


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