Constrained Fatigue Life Optimization of a Nasvytis Multiroller Traction Drive

1981 ◽  
Vol 103 (2) ◽  
pp. 423-428 ◽  
Author(s):  
J. J. Coy ◽  
D. A. Rohn ◽  
S. H. Loewenthal
Keyword(s):  
Fatigue Life ◽  
Contact Fatigue ◽  
Rolling Element Bearing ◽  
Analysis Method ◽  
Traction Drive ◽  
Adjustment Factors ◽  
Contact Fatigue Life ◽  
Traction Drives ◽  
Fatigue Life Analysis ◽  
Continuous Power

A contact fatigue life analysis method for multiroller traction drives is presented. The method is based on the Lundberg-Palmgren analysis method for rolling element bearing life prediction, and also uses life adjustment factors for materials, processing, lubrication, and effect of traction. The analysis method is applied in an optimization study to the multiroller traction drive, consisting of a single-stage planetary configuration with two rows of stepped planet rollers of five rollers per row. The drive was approximately 25 centimeters in diameter by 11 centimeters long, having a nominal ratio of 15:1. The theoretically predicted drive life was 2510 hours at a nominal continuous power and speed of 74.6 kW (100 hp) and 75,000 rpm.

Ball Spalling in Rolling Element Bearings: Decrease in Rolling Contact Fatigue Life Due to Inferior Microstructure and Manufacturing Processes

2021 ◽  
Author(s):  
Graham Keep ◽  
Mark Wolka ◽  
Beth Brazitis
Keyword(s):  
Fatigue Life ◽  
Rolling Contact Fatigue ◽  
Microstructural Analysis ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Rolling Element Bearing ◽  
Bench Test ◽  
Bearing Life ◽  
Rolling Element ◽  
Contact Fatigue Life

Abstract Through hardened steel ball fatigue failure is an atypical mode of failure in a rolling element bearing. A recent full-scale bench test resulted in ball spalling well below calculated bearing life. Subsequent metallurgical analysis of the spalled balls found inferior microstructure and manufacturing methods. Microstructural analysis revealed significant carbide segregation and inclusions in the steel. These can result from substandard spheroidized annealing and steel making practices. In addition, the grain flow of the balls revealed a manufacturing anomaly which produced a stress riser in the material making it more susceptible to crack initiation. The inferior manufactured balls caused at least an 80% reduction in rolling contact fatigue life of the bearing.

Axial Load Effect on Contact Fatigue Life of Cylindrical Roller Bearings

2004 ◽  
Vol 126 (2) ◽  
pp. 242-247 ◽  
Author(s):  
Wangquan (Winston) Cheng ◽  
Shan Shih ◽  
John Grace ◽  
Wenke Tu
Keyword(s):  
Fatigue Life ◽  
Axial Load ◽  
Roller Bearing ◽  
Contact Fatigue ◽  
Limit Load ◽  
Load Effect ◽  
Roller Bearings ◽  
Contact Fatigue Life ◽  
Fatigue Life Analysis ◽  
Cylindrical Roller

Besides primarily carrying radial load, cylindrical roller bearings with flanges or lips on both inner and outer raceways need also carry axial load in some applications. Because of the axial load, the equivalent dynamic load of the bearing will be increased and the bearing contact fatigue life will be decreased accordingly. The axial load effect on the roller bearing fatigue life had been studied by researchers in the past. Because of different assumptions used in their models, quite different predictions were made in their analysis. This work combines the methods used in the Fernlund-Synek and Brandlein models and studies general contact conditions such as partial contact along the roller length, partial loading zone of the bearing race, manufacturing tolerance and running-in effects on roller length, etc. New formulas for equivalent dynamic loads of the rotating and stationary races are derived. A fatigue limit load is also included in the life calculation to reflect the latest development in contact fatigue life analysis.

Contact Fatigue Tests and Contact Fatigue Life Analysis

2005 ◽  
Author(s):  
Hong Lin ◽  
Robert R. Binoniemi ◽  
Gregory A. Fett ◽  
Mick Deis
Keyword(s):  
Fatigue Life ◽  
Contact Fatigue ◽  
Fatigue Tests ◽  
Contact Fatigue Life ◽  
Life Analysis ◽  
Fatigue Life Analysis

Effect of Grain Flow Orientation on Rolling Contact Fatigue Life of AISI M-50

1982 ◽  
Vol 104 (3) ◽  
pp. 330-334 ◽  
Author(s):  
A. H. Nahm
Keyword(s):  
Fatigue Life ◽  
Flow Line ◽  
Flow Direction ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Vacuum Arc ◽  
Type I ◽  
Grain Flow ◽  
Contact Fatigue Life

Accelerated rolling contact fatigue tests were conducted to study the effect of grain flow orientation on the rolling contact fatigue life of vacuum induction melted and vacuum arc remelted (VIM-VAR) AISI M-50. Cylindrical test bars were prepared from a billet with 0, 45, and 90 deg orientations relative to billet forging flow direction. Tests were run at a Hertzian stress of 4,826 MPa with a rolling speed of 12,500 rpm at room temperature, and lubricated with Type I (MIL-L-7808G) oil. It was observed that rolling contact fatigue life increased when grain flow line direction became more parallel to the rolling contact surface.

Influence of ZnDTP on Rolling Contact Fatigue Life under Grease Lubrication

2021 ◽  
Vol 2021.59 (0) ◽  
pp. 05a5
Author(s):  
Hirotomo HOSOI ◽  
Yugo KAMEI ◽  
Hirotoshi AKIYAMA ◽  
Jusei MAEDA ◽  
Masanori SEKI
Keyword(s):  
Fatigue Life ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Grease Lubrication ◽  
Contact Fatigue Life
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