Comparative bending fatigue strength of precision forged spur gears

To determine the bending fatigue strength of precision forged spur gears and to compare the results with those obtained from conventional cut gears, single tooth bending fatigue tests were carried out on both through-hardened and induction-hardened gear teeth. The gears were produced from rolled bar cut blanks, disc forged blanks or precision forged teeth blanks. For this purpose, a special test fixture was designed and built for an Amsler high-frequency vibrophore fatigue testing machine. The results show that the endurance limit of precision forged gears is significantly higher than those obtained from cut gears. The bending fatigue strength of forged gears was some 12.5 per cent higher than the cut teeth in a through-hardened condition and 8.4 per cent higher for the induction-hardened teeth. The effect of surface roughness at the tooth root area on the bending fatigue strength of the forged gears is also shown.

Download Full-text

The Evaluation of Bending Fatigue Testing of Austempered Ductile Iron Spur Gear

Volume 10: 2019 International Power Transmission and Gearing Conference ◽

10.1115/detc2019-97194 ◽

2019 ◽

Author(s):

Qi Zhang ◽

Jianhua Lv ◽

Rizwanulhaque Syed ◽

Jing Zhang ◽

Yang Xu ◽

...

Keyword(s):

Fatigue Strength ◽

Ductile Iron ◽

Fatigue Testing ◽

Spur Gear ◽

Austempered Ductile Iron ◽

Spur Gears ◽

Reliability Design ◽

Bending Fatigue ◽

Bending Fatigue Strength ◽

Number Of Cycles

Abstract An experimental evaluation of bending fatigue strength for austempered ductile iron (ADI) spur gears have been performed using Zwick fatigue tester. The gear material was manufactured by vertically continuous casting, in which the radius of the graphite grains is smaller. The Stress-Number of Cycles curve (S-N curve) for the bending fatigue strength of the ADI spur gears are manufactured without any specific surface treatments, and have been obtained by post-processing software. It was observed that when the reliability was 50%, the fatigue limit was 304.89 MPa. It has provided a reliable basis to rate the reliability design of the small gearboxes in automation later.

Download Full-text

Application of Fluidic-Deice Type Fatigue Testing Machine. Evaluation of Reversed Plane-Bending Fatigue Strength of Cold Rolled Steel Sheets Bent to 90.DEG.V-shape.

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C ◽

10.1299/kikaic.64.4863 ◽

1998 ◽

Vol 64 (628) ◽

pp. 4863-4868

Author(s):

Noboru YAHATA ◽

Masaaki WATANABE ◽

Hideki YAMAMOTO

Keyword(s):

Fatigue Strength ◽

Fatigue Testing ◽

Testing Machine ◽

Rolled Steel ◽

Bending Fatigue ◽

Cold Rolled Steel ◽

Steel Sheets ◽

Cold Rolled ◽

Bending Fatigue Strength ◽

Plane Bending

Download Full-text

Residual Stress and Bending Fatigue Strength of Case-Carburized Thin-Rimmed Spur Gears With Asymmetric Web Arrangement

Volume 7: 10th International Power Transmission and Gearing Conference ◽

10.1115/detc2007-34047 ◽

2007 ◽

Author(s):

Kouitsu Miyachika ◽

Wei-Dong Xue ◽

Takao Koide ◽

Hidefumi Mada ◽

Kengo Nojima ◽

...

Keyword(s):

Residual Stress ◽

Fatigue Strength ◽

Three Dimensional ◽

Spur Gear ◽

Fatigue Tests ◽

Case Depth ◽

Spur Gears ◽

3D Fem ◽

Bending Fatigue ◽

Bending Fatigue Strength

This paper presents a study on effects of carburized parts on residual stress and bending fatigue strength of case-carburized thin-rimmed spur gears with asymmetric web arrangement. A heat conduction analysis and an elastic-plastic stress analysis for the case-carburizing process of thin-rimmed spur gears with asymmetric web arrangement were carried out by the three-dimensional finite-element method (3D-FEM), and then residual stresses were obtained. Effects of the case depth, the carburized part and the rim thickness on the residual stress of case-carburized thin-rimmed spur gears were determined. Bending fatigue tests were carried out for case-carburized thin-rimmed spur gears with asymmetric web arrangement, and S-N curves and bending fatigue limit loads were obtained. Effects of the case-depth, the carburized part and the rim thickness on the bending fatigue strength of the case-carburized thin-rimmed spur gear with asymmetric web arrangement were determined.

Download Full-text

Bending fatigue strength and impact strength of spur gears with various surface hardening treatments

The Proceedings of Conference of Chugoku-Shikoku Branch ◽

10.1299/jsmecs.2021.59.05a1 ◽

2021 ◽

Vol 2021.59 (0) ◽

pp. 05a1

Author(s):

Ryo ASAKURA ◽

Kohei HIBI ◽

Kenichi SAKAMOTO ◽

Toshiyasu OMURA ◽

Ryosuke NISHI ◽

...

Keyword(s):

Fatigue Strength ◽

Impact Strength ◽

Surface Hardening ◽

Spur Gears ◽

Bending Fatigue ◽

Bending Fatigue Strength

Download Full-text

Effects of case depth, face width and intergranular oxidation on bending fatigue strength of case-carburized SNC815 and SCM415 steel spur gears

International Gear Conference 2014: 26th–28th August 2014, Lyon ◽

10.1533/9781782421955.950 ◽

2014 ◽

pp. 950-958 ◽

Cited By ~ 1

Author(s):

K. Miyachika ◽

T. Ikuta ◽

N. Maeta ◽

H. Mada

Keyword(s):

Fatigue Strength ◽

Case Depth ◽

Spur Gears ◽

Bending Fatigue ◽

Face Width ◽

Intergranular Oxidation ◽

Bending Fatigue Strength

Download Full-text

Tooth Root Bending Fatigue Strength of High-Density Sintered Small-Module Spur Gears: The Effect of Porosity and Microstructure

Metals ◽

10.3390/met9050599 ◽

2019 ◽

Vol 9 (5) ◽

pp. 599 ◽

Cited By ~ 1

Author(s):

Vigilio Fontanari ◽

Alberto Molinari ◽

Michelangelo Marini ◽

Wolfgang Pahl ◽

Matteo Benedetti

Keyword(s):

Fatigue Strength ◽

Surface Defect ◽

Detrimental Effect ◽

Case Hardening ◽

Spur Gears ◽

Tooth Root ◽

Near Surface ◽

Bending Fatigue ◽

Microstructural Constituent ◽

Bending Fatigue Strength

The present paper is aimed at investigating the effect of porosity and microstructure on tooth root bending fatigue of small-module spur gears produced by powder metallurgy (P/M). Specifically, three steel variants differing in powder composition and alloying route were subjected either to case-hardening or sinter-hardening. The obtained results were interpreted in light of microstructural and fractographic inspections. On the basis of the Murakami a r e a method, it was found that fatigue strength is mainly dictated by the largest near-surface defect and by the hardness of the softest microstructural constituent. Owing to the very complicated shape of the critical pore, it was found that its maximum Feret diameter is the geometrical parameter that best captures the detrimental effect on fatigue.

Download Full-text

Bending Fatigue Tests of High Speed Spur Gears

Journal of Mechanical Design ◽

10.1115/1.3254941 ◽

1981 ◽

Vol 103 (2) ◽

pp. 466-473 ◽

Cited By ~ 3

Author(s):

I. Yuruzume ◽

H. Mizutani

Keyword(s):

High Speed ◽

Normal Load ◽

Load Capacity ◽

Spur Gear ◽

Fatigue Tests ◽

Spur Gears ◽

Bending Fatigue ◽

Tooth Width ◽

Bending Load ◽

Bending Fatigue Strength

Effects of addendum modification of tooth profiles on the bending fatigue strength of high speed spur gear are discussed in this presentation: A JIS Class O Spur gear of m3, α20 deg, Z1 27, and made of AMS 6260 (AISI 9310) steel precisely ground after carburizing and hardening was meshed with the other gear of Z2 77 and operated at 8550 rpm. In this running test, bending load capacity and running performance comparisons between the gear with standard tooth profile and the two shifted gears of which tooth addendum modification coefficients were 0.35 and 0.8. The maximum normal load of the gear with addendum modification coefficient 0.8 at 107 (10 million) cycles was 1.8 kNsmm per unit tooth width. The maximum Hertz stress of this gear was 2.43 × 109 Nsm2. The allowable normal load of the gear with 0.8 was higher than that of the standard gear by 87 percent and higher than of the 0.35 profile shifted gears by 20 percent.

Download Full-text