Application of Miner's Rule to Industrial Gear Drives
We need a method to analyze cumulative fatigue damage to specify and to design gear drives which will operate under varying load. Since load is seldom constant, most applications need this analysis.
Surface Fatigue Life on CBN and Vitreous Ground Carburized and Hardened AISA 9310 Spur Gears
Spur gear surface endurance tests were conducted to investigate CBN ground AISI 9310 spur gears for use in aircraft applications, to determine their endurance characteristics and to compare the results with the endurance of standard vitreous ground AISI 9310 spur gears. Tests were conducted with VIM-VAR AISI 9210 carburized and hardened gears that were finish ground with either CBN or vitreous grinding methods. Test conditions were an inlet oil temperature of 320 K (116 degree F), an outlet oil temperature of 350 K (170 degree F), a maximum Hertz stress of 1.71 GPa (248 ksi), and a speed of 10,000 rpm. The CBN ground gears exhibited a surface fatigue life that was slightly better than the vitreous ground gears. The subsurface residual stress of the CBN ground gears was approximately the same as that for the standard vitreous ground gears for the CBN grinding method used.
Kudos To AGMA for Pittsburgh Show (Publishers Page)
AGMA's Gear Expo '89 was, by all accounts, a great success, proving again the wisdom of having a trade show devoted exclusively to gearing and gear-related products. Over 1500 people attended the show, and 86 different companies exhibited their goods and services.
Technical Calendar (Events)
Complete technical calendar for January/February 1990
Achievable Carburizing Specifications (Back to Basics)
A widespread weakness of gear drawings is the requirements called out for carburize heat treating operations. The use of heat treating specifications is a recommended solution to this problem. First of all, these specifications guide the designer to a proper callout. Secondly, they insure that certain metallurgical characteristics, and even to some extent processing, will be obtained to provide the required qualities in the hardened gear. A suggested structure of carburizing specifications is give.