scholarly journals Geometrical Optimization of the EHL Roller Face/Rib Contact for Energy Efficiency in Tapered Roller Bearings

Lubricants ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 67
Author(s):  
Sven Wirsching ◽  
Max Marian ◽  
Marcel Bartz ◽  
Thomas Stahl ◽  
Sandro Wartzack
Keyword(s):  
Energy Efficiency ◽  
Carrying Capacity ◽  
Tribological Behavior ◽  
Large Radius ◽  
Load Carrying Capacity ◽  
Statistical Design Of Experiments ◽  
Roller Bearings ◽  
Load Carrying ◽  
Tapered Roller ◽  
Tapered Roller Bearings

In the context of targeted improvements in energy efficiency, secondary rolling bearing contacts are gaining relevance. As such, the elastohydrodynamically lubricated (EHL) roller face/rib contact of tapered roller bearings significantly affects power losses. Consequently, this contribution aimed at numerical optimization of the pairing’s macro-geometric parameters. The latter were sampled by a statistical design of experiments (DoE) and the tribological behavior was predicted by means of EHL contact simulations. For each of the geometric pairings considered, a database was generated. Key target variables such as pressure, lubricant gap and friction were approximated by a meta-model of optimal prognosis (MOP) and optimization was carried out using an evolutionary algorithm (EA). It was shown that the tribological behavior was mainly determined by the basic geometric pairing and the radii while eccentricity was of subordinate role. Furthermore, there was a trade-off between high load carrying capacity and low frictional losses. Thereby, spherical or toroidal geometries on the roller end face featuring a large radius paired with a tapered rib geometry were found to be advantageous in terms of low friction. For larger lubricant film heights and load carrying capacity, spherical or toroidal roller on toroidal rib geometries with medium radii were favorable.

The Axial Load-Carrying Capacity of Radial Cylindrical Roller Bearings

1970 ◽  
Vol 92 (1) ◽  
pp. 129-134 ◽  
Author(s):  
H. Korrenn
Keyword(s):  
Carrying Capacity ◽  
Hydrodynamic Lubrication ◽  
Experimental Investigations ◽  
Load Carrying Capacity ◽  
Oil Viscosity ◽  
Application Range ◽  
Roller Bearings ◽  
Load Carrying ◽  
Thrust Load ◽  
Cylindrical Roller

Thrust load transmission at the contact areas of roller ends and flanges occurs under conditions of pure sliding. Recent theoretical and experimental investigations showed that with adequately designed roller ends and flanges and with a satisfactory lubricant high thrust loads can be accommodated over a wide speed range with fully hydrodynamic lubrication. The conventional methods used for the determination of the safe thrust load should be revised and supplemented. Oil viscosity should be introduced as an important parameter. Contrary to present opinion the hydrodynamic load-carrying capacity at the flange increases with increasing speed. This new knowledge broadens the application range of radial cylindrical roller bearings.

Vibrational Characteristics of Tapered Roller Bearing Cages

2000 ◽  
Author(s):  
J. A. Karloff ◽  
W. N. Weins ◽  
R. C. Arnold
Keyword(s):  
Roller Bearing ◽  
Main Function ◽  
Tapered Roller Bearing ◽  
Roller Bearings ◽  
Railway Industry ◽  
Load Carrying ◽  
Modeling Software ◽  
Vibrational Characteristics ◽  
Tapered Roller ◽  
Tapered Roller Bearings

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.

Experimental Study on the Tribological Behavior of CaCO3/PEEK Composites under Water Lubrication

2010 ◽  
Vol 139-141 ◽  
pp. 98-101 ◽  
Author(s):  
You Xi Lin ◽  
Cheng Hui Gao ◽  
Yuan Li
Keyword(s):  
Experimental Study ◽  
Wear Resistance ◽  
Carrying Capacity ◽  
Tribological Behavior ◽  
Weight Percent ◽  
Transfer Film ◽  
Water Lubrication ◽  
Load Carrying Capacity ◽  
Caco3 Content ◽  
Load Carrying

The tribological properties of PEEK composites filled with CaCO3 whisker in various content of 0-30%(weight percent) were investigated.The composite specimens were prepared by compression molding. Tribological testing of composites in water lubrication against carbon steel ring was carried out on a MM200 block-on-ring apparatus.Data on neat PEEK were also included for comparison. The morphologies of wear traces were observed by SEM.It was observed that inclusion of CaCO3 whisker significantly improved the wear resistance and reduced the friction coefficient of PEEK composites under water lubricated condition. With an increase in CaCO3 whisker contents, the specific wear rate of composites decreased and showed minima for 20% CaCO3 content as 5.2% of that for PEEK. In terms of friction applications under water lubrication, the optimal content of CaCO3 whisker in PEEK composites should be recommended as 15% to 20%.The SEM observation of the wear traces indicated that the transfer film is not the main reason for the enhancement of wear resistance of the composites in water lubrication.CaCO3 whisker contributed to increase the load-carrying capacity and abate the scuffing and adhesion of PEEK composites, finally led to a significant improvement of the wear resistance.

Paper 3: Fluid Lubrication of Tapered Roller Bearings

1969 ◽  
Vol 184 (12) ◽  
pp. 18-25 ◽  
Author(s):  
G. R. Higginson ◽  
R. H. Leaver
Keyword(s):  
Axial Loading ◽  
Operating Conditions ◽  
Test Rig ◽  
Detailed Consideration ◽  
Mineral Oils ◽  
Roller Bearings ◽  
Wide Range ◽  
Load Carrying ◽  
Tapered Roller ◽  
Tapered Roller Bearings

A new test rig is used to investigate the mode of lubrication of tapered roller bearings under axial loading. Two different bearing configurations for a 21/4-in shaft are used. The lubricants are mineral oils. The investigation establishes the nature of the lubrication at the load-carrying points in the bearing, at the inner and outer rings, and at the flange on the inner ring. Measurements of friction losses are made over a wide range of operating conditions; these are analysed theoretically, and are substantially accounted for by modern lubrication theory and a detailed consideration of the geometry of the bearings as a whole.

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