scholarly journals A Life Study of Ausforged, Standard Forged, and Standard Machined AISI M-50 Spur Gears

1976 ◽  
Vol 98 (3) ◽  
pp. 418-425 ◽  
Author(s):  
D. P. Townsend ◽  
E. N. Bamberger ◽  
E. V. Zaretsky
Keyword(s):  
Fatigue Life ◽  
Gear Tooth ◽  
Vacuum Arc ◽  
Spur Gears ◽  
Bending Fatigue ◽  
Life Study ◽  
Tooth Fracture ◽  
The Difference

Tests were conducted at 350 K (170° F) with three groups of 8.9 cm (3.5 in.) pitch diameter spur gears made of vacuum-induction melted (VIM), vacuum-arc remelted (VAR), AISI M-50 steel and one group of vacuum-arc remelted (VAR) AISI 9310 steel. The pitting fatigue life of the standard forged and ausforged gears was approximately five times that of the VAR AISI 9310 gears and ten times that of the bending fatigue life of the standard machined VIM-VAR AISI M-50 gears run under identical conditions. There was a slight decrease in the 10-percent life of the ausforged gears from that for the standard forged gears. However, the difference is not statistically significant. The standard machined gears failed primarily by gear tooth fracture while the forged and ausforged VIM-VAR AISI M-50 and the VAR AISI 9310 gears failed primarily by surface pitting fatigue. The ausforged gears had a slightly greater tendency to fail by tooth fracture than the standard forged gears.

scholarly journals A Life Study of AISI M-50 and Super Nitralloy Spur Gears With and Without Tip Relief

1974 ◽  
Vol 96 (4) ◽  
pp. 583-589 ◽  
Author(s):  
D. P. Townsend ◽  
E. V. Zaretsky
Keyword(s):  
Gear Tooth ◽  
Spur Gear ◽  
Consumable Electrode ◽  
Spur Gears ◽  
Life Study ◽  
Tooth Fracture ◽  
The Difference

Tests were conducted at 350 K (170 deg F) with groups of 8.9 cm (3.5-in.)-pitch-diameter spur gear with and without tip relief made of consumable-electrode vacuum melted (CVM) Super Nitralloy (5Ni-2Al) and CVM AISI M-50 steel. The AISI M-50 gears without tip relief had lives approximately 50 percent longer than the Super Nitralloy gears without tip relief. However, the Super Nitralloy gears with tip relief had lives equal to the AISI M-50 gears without tip relief. The difference in lives were not statistically significant. All gears failed by classical pitting fatigue at the pitch circle. However, the AISI M-50 gears with tip relief failed by tooth fracture. AISI M-50 gear sets without tip relief having a spalled gear tooth which were deliberately overrun after spalling had occurred, failed by tooth fracture.

Numerical model for bending fatigue life estimation of carburized spur gears with consideration of the adjacent tooth effect

2021 ◽  
Vol 153 ◽  
pp. 106515
Author(s):  
Krešimir Vučković ◽  
Ivan Čular ◽  
Robert Mašović ◽  
Ivica Galić ◽  
Dragan Žeželj
Keyword(s):  
Fatigue Life ◽  
Numerical Model ◽  
Spur Gears ◽  
Bending Fatigue ◽  
Life Estimation ◽  
Adjacent Tooth ◽  
Fatigue Life Estimation

Optimization of Tooth Bending Fatigue Characteristics of Spur Gear Pairs Using a Gear Dynamics-Based Approach

2015 ◽  
Author(s):  
Yalın Öztürk ◽  
Ender Ciğeroğlu ◽  
H. Nevzat Özgüven
Keyword(s):  
Fatigue Life ◽  
Gear Tooth ◽  
Spur Gear ◽  
Bending Fatigue ◽  
Gear Dynamics ◽  
Optimization Study ◽  
Fatigue Life Estimation ◽  
Fatigue Characteristics ◽  
Profile Optimization ◽  
Operational Range

A gear tooth profile optimization study is performed with the target being defined as the maximization of tooth bending fatigue life for a selected operational range, where the operating torque and speed ranges are defined along with their corresponding durations. For this purpose, a nonlinear lumped gear dynamics model is combined with the S/N curve of the gear material in order to estimate tooth bending fatigue life of the spur gear pair. The differences between the predicted lives of the optimally modified and non-modified gear pairs are presented based on example spur gear pairs. The proposed tooth bending fatigue life estimation is compared with the standard AGMA procedure.

Numerical calculation of bending fatigue life of thin-rim spur gears

2004 ◽  
Vol 71 (4-6) ◽  
pp. 647-656 ◽  
Author(s):  
J. Kramberger ◽  
M. Šraml ◽  
I. Potrč ◽  
J. Flašker
Keyword(s):  
Fatigue Life ◽  
Numerical Calculation ◽  
Spur Gears ◽  
Bending Fatigue

An Experimental Evaluation of High-Cycle Gear Tooth Bending Fatigue Lives Under Fully Reversed and Fully Released Loading Conditions With Application to Planetary Gear Sets

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Isaac J. Hong ◽  
Ahmet Kahraman ◽  
Neil Anderson
Keyword(s):  
Fatigue Life ◽  
Gear Tooth ◽  
Planetary Gear ◽  
Fatigue Tests ◽  
Experimental Methodology ◽  
Tooth Root ◽  
Loading Conditions ◽  
Bending Fatigue ◽  
Equivalent Number ◽  
Stress Ratios

Abstract High-cycle gear tooth bending fatigue lives of spur gears under fully reversed and fully released loading conditions are compared in this experimental study. The experimental methodology described in an earlier publication, (Hong et al. 2020, “A Rotating Gear Test Methodology for Evaluation of High-Cycle Tooth Bending Fatigue Lives Under Fully Reversed and Fully Released Loading Conditions,” Int. J. Fatigue, 133, p. 105432. 10.1016/j.ijfatigue.2019.105432), is employed to perform two sets of rotating, gear tooth bending fatigue tests. Statistical analyses are performed to regress stress versus life (S–N) curves under both loading conditions. These curves indicate that a gear under fully reversed loads has a shorter bending life at the same maximum tooth root stress as a gear under fully released loads. Various planetary gear set kinematic conditions with different stationary members are considered to determine the equivalent number of tooth loading cycles per revolution of the sun gear. They are combined with established S–N curves under both loading conditions to determine the ratios of allowable maximum tooth root stresses amongst the gear components of a P-planet gear set such that each gear in the set has the same bending fatigue life. A “stress-balanced” gear set designed to these stress ratios is expected to have the same bending fatigue life for its sun, ring, and planet gears, ensuring that the planetary gear set life is the longest.

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.

Into Mesh Lubrication of Spur Gears With Arbitrary Offset Oil Jet. Part 1: For Jet Velocity Less Than or Equal to Gear Velocity

1983 ◽  
Vol 105 (4) ◽  
pp. 713-718 ◽  
Author(s):  
L. S. Akin ◽  
D. P. Townsend
Keyword(s):  
Inclination Angle ◽  
Gear Tooth ◽  
Optimum Operating ◽  
Spur Gears ◽  
Optimum Operating Condition ◽  
Operating Condition ◽  
The Common ◽  
Jet Velocity ◽  
Oil Jet

An analysis was conducted for into mesh oil jet lubrication with an arbitrary offset and inclination angle from the pitch point for the case where the oil jet velocity is equal to or less than pitch line velocity. The analysis includes the case for the oil jet offset from the pitch point in the direction of the pinion and where the oil jet is inclined to intersect the common pitch point. Equations were developed for the minimum oil jet velocity required to impinge on the pinion or gear and the optimum oil jet velocity to obtain the maximum impingement depth. The optimum operating condition for best lubrication and cooling is provided when the oil jet velocity is equal to the gear pitch line velocity with both sides of the gear tooth cooled. When the jet velocity is reduced from pitch line velocity the drive side of the pinion and the unloaded side of the gear is cooled. When the jet velocity is much lower than the pitch line velocity the impingement depth is very small and may completely miss the pinion.

Fatigue Life Prediction of Gear Transmission Based on ANSYS

2014 ◽  
Vol 1055 ◽  
pp. 161-164
Author(s):  
Tao Wang ◽  
Wei Zhong Zhang ◽  
Chen Xie ◽  
Deng Xia Zhang ◽  
Yan Ru
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
Reliable Data ◽  
Cumulative Damage ◽  
Gear Transmission ◽  
Fatigue Life Prediction ◽  
Nominal Stress ◽  
Bending Fatigue ◽  
Unmanned System ◽  
Damage Theory

With the study subject of the gear transmission in an unmanned system, several common methods of fatigue life prediction are analyzed. According to the actual running state, S-N nominal stress method is used to predict the fatigue life of the gears. Based on the S-N data of the gear material and the linear cumulative damage theory, ANSYS is used to estimate the bending fatigue life of the gears, so as to obtain the fatigue life loss coefficient of the gears. It provides a reliable data reference of the design, use and maintenance of the gear transmission in unmanned system.

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