Fatigue Prediction of Thin Hard Coatings on the Steel Races of Hybrid Bearings Used in High Speed Machine Tool Spindles

1998 ◽  
Vol 120 (4) ◽  
pp. 835-842 ◽  
Author(s):  
K.-D. Bouzakis ◽  
N. Vidakis ◽  
S. Mitsi
Keyword(s):  
High Speed ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Fem Simulation ◽  
Bearing Steel ◽  
Fatigue Tests ◽  
Rolling Contact ◽  
Hard Coatings ◽  
Long Duration ◽  
The Impact

The rotational speed requirements of high speed spindles led to the development of angular contact hybrid bearings with ceramic balls and PVD coated steel races. The present paper describes the determination and verification of critical coating fatigue stresses as well as their application in coating fatigue calculations of hybrid bearing steel races. The fatigue limits of low temperature deposited PVD coatings were determined by the application of the impact test and its FEM simulation and validated through their successful application to the prediction of coating life in rolling contact fatigue tests of coated specimens. Furthermore, a computer program that performs the quasi-static simulation of bearing operation yields the necessary kinematic and dynamic parameters for a FEM simulation of the stress field occurring in coated rings. For the investigated bearings, an adequate fatigue performance of their coated races was computationally exhibited. The PVD coated hybrid bearings illustrated the predicted behavior in long duration tests, conducted in full scale test rigs.

Theory of Lubrication and Failure of Rolling Contacts

1961 ◽  
Vol 83 (2) ◽  
pp. 213-222 ◽  
Author(s):  
B. Sternlicht ◽  
P. Lewis ◽  
P. Flynn
Keyword(s):  
Fatigue Life ◽  
Contact Zone ◽  
High Speed ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Fatigue Tests ◽  
Rolling Contact ◽  
Inlet Temperature ◽  
Fluid Properties ◽  
Contact Fatigue Life

The fatigue life of rolling-element bearings has been the subject of numerous investigations. Most recently the influence of the lubricant on fatigue failure has been given added emphasis. This paper presents the results of an investigation which was undertaken in order to gain a better understanding of fluid behavior in the contact zone and to determine the influence of the lubricant on rolling contact fatigue life. The investigation had three distinct facets: (a) An analysis was performed on pressure and temperature distribution within the contact zone of rolling disks. In the analysis Reynolds, energy, and elasticity equations were solved simultaneously and fluid properties, such as viscosity dependence on temperature and pressure were included. (b) Dynamic stresses in two contacting cylindrical bodies were measured by means of photoelastic techniques. These measurements were used to test the validity of the analytically predicted stress distribution. (c) High-speed ball-bearing fatigue tests were conducted with two specially blended oils which had the same viscosity at the bearing inlet temperature, but widely different pressure viscosity characteristics. The physical characteristics of the oils were the same as those considered in the analysis. The paper summarizes the work and presents a hypothesis for the failure mechanism.

The Impact of Surface Integrity by Hard Turning vs. Grinding on Rolling Contact Fatigue

2007 ◽  
Author(s):  
A. W. Warren ◽  
Y. B. Guo
Keyword(s):  
Acoustic Emission ◽  
Surface Integrity ◽  
Hard Turning ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Fatigue Tests ◽  
Rolling Contact ◽  
Polished Surface ◽  
Emission Signal ◽  
The Impact

Hard turning and grinding are finishing processes for the manufacture of precision components such as bearings, gears, and cams. However, the effects of distinct surface integrity by hard turning vs. grinding on rolling contact life are poorly understood. Four representative surface types were prepared: as-turned, as-ground, turned and polished, and ground and polished. Surface integrity was characterized by surface topography, microstructure, and micro/nanohardness. Fatigue tests were performed with an acoustic emission sensor and the signal processing software. The amplitude of acoustic emission signal is the most stable and sensitive signal to fatigue failure. The turned surface may have a longer life (>84%) than the ground one with equivalent surface finish.

Paper 4: Study of the Effect of Material Combination and Hardness in Rolling Contact

1965 ◽  
Vol 180 (11) ◽  
pp. 32-36 ◽  
Author(s):  
D. Scott ◽  
J. Blackwell
Keyword(s):  
High Speed ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Bearing Steel ◽  
Rolling Contact ◽  
Material Combination ◽  
Premature Failure ◽  
Contact Fatigue Life ◽  
En 31 ◽  
Steel Balls

Because of uneven stressing, environment, or lubricant effects, one element of a rolling mechanism may be prone to premature failure, and it has been found in some instances that the seemingly easy solution of replacing the element with one manufactured in a superior material has not been successful. By means of the simple rolling four-ball test, the effect of the combination of material in rolling contact has been studied. The effect on the incidence of rolling-contact fatigue of running different materials such as high-speed tool steels, stainless steels, and other wear resistant materials potentially suitable for rolling elements against one another and against conventional En 31 ball-bearing steel has been explored. The effect of various hardness combinations of En 31 steel balls has been determined. The choice of material combination is shown to be a major factor in enhancing or reducing the performance of either mating material. With En 31 steel there appears to be an optimum hardness range and the hardness of both surfaces is important to ensure a maximum rolling-contact fatigue life. Metallurgical investigations have been carried out to elucidate the mechanisms of failure, and ‘compatibility’ is discussed in the light of fundamental concepts of the initiation of surface fatigue by mechanisms such as reversed micro-plastic deformation and how these mechanisms, the contact area, and the stress distribution are influenced by the material properties such as hardness and by rolling and sliding action.

scholarly journals Wear and Rolling Contact Fatigue Analysis of AISI 52100 Bearing Steel in Presence of Additivated Lubricants

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 907
Author(s):  
Shubrajit Bhaumik ◽  
Viorel Paleu
Keyword(s):  
Surface Characterization ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Mineral Oil ◽  
Bearing Steel ◽  
Fatigue Tests ◽  
Life Cycles ◽  
Rolling Contact ◽  
Molybdenum Disulphide ◽  
Aisi 52100

Tribological properties of lithium potassium titanate (PT), molybdenum disulphide, and tungsten disulphide-dispersed mineral oil (MO) were investigated. The sample containing 2 wt.% WS2 exhibited the lowest coefficient of friction. However, the wear scar diameters of the additivated samples were very narrow. Extreme pressure properties of mineral oil were enhanced with the addition of additives. The rolling contact fatigue results exhibited better fatigue life of the balls in MoS2 and PT-dispersed MO. Surface characterization of the balls indicated more pitting on the balls of the MO and WS2-dispersed MO as compared to MoS2 and PT, indicating a stable film in the case of MoS2 and PT, which was confirmed by the presence of additives on ball surfaces by Raman spectrograph. The results of extended rolling contact fatigue tests proved that PT-added mineral oil provided the highest life cycles of the tested balls, followed by MoS2 and WS2-added mineral oil; thus, indicating PT as a plausible alternative to MoS2 and WS2.

Influence on Tribological Behavior of PEEK Composite Film Layer on PEEK-PTFE Bearings with Artificial Defect in Dry Condition

2021 ◽  
Vol 904 ◽  
pp. 243-249
Author(s):  
Hitonobu Koike ◽  
Koshiro Mizobe ◽  
Katsuyuki Kida
Keyword(s):  
Composite Film ◽  
Tribological Behavior ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Fatigue Tests ◽  
Rolling Contact ◽  
Artificial Defect ◽  
Peek Composite ◽  
Film Layer ◽  
Number Of Cycles

In order to explore influence on tribological behavior of PEEK composite film layer in PEEK-PTFE composite radial alumina ball bearings, rolling contact fatigue tests were performed by using the PEEK bearing’s inner rings with the artificial defects in dry condition. When rotation speed and applied load were 600 rpm and 98 N, the number of cycles of the PEEK-PTFE bearings reached 1.0×107 fatigue cycles. The artificial defects with 0.02 mm depth on the raceway surface of the PEEK inner ring was covered with PEEK composite film accumulation.

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