Evaluation of carburized and ground face gears

Experimental durability tests were performed on carburized and ground AISI 9310 steel face gears. The tests were in support of a Defense Advanced Rese arch Projects Agency (DARPA) Technology Reinvestment Program (TRP) to enhan ce face-gear technology. The tests were conducted in the NASA Glenn spiral- bevel-gear/face-gear test facility, Tests were run at 2300 rpm face gear sp eed and at loads of 64, 76, 88, 100, and 112-percent of the design torque o f 377 N-m (3340 in.-lb.). The carburized and ground face gears demonstrated the required durability when run for ten-million cycles at each of the app lied loads. proper installation was critical for the successful operation o f the spur pinions and face gears. A large amount of backlash produced toot h contact patterns that approached the inner-diameter edge of the fate-gear tooth. Low backlash produced tooth contact patterns that approached the ou ter-diameter edge of the face-gear tooth. Measured backlashes in the range of 0.178 to 0.254 mm (0.007 to 0.010 in.) produced acceptable tooth contact patterns.