ABSTRACT
Experimental comparison of the traditionally designed symmetric gears and asymmetric directly designed gears was done by the Rotorcraft division of the Boeing Company. Asymmetric and baseline symmetric toothed gear test specimens were designed, fabricated, and tested to experimentally determine their single tooth bending fatigue strength and scuffing resistance. Standardized traditional toothed designs have been developed for bending fatigue and scuffing test rigs that Boeing Rotorcraft uses for gear research. For comparison, conventional symmetric involute gears and gears with asymmetric involute teeth were designed and tested. The asymmetric gear specimens and baseline symmetric circular fillet test gears were fabricated by Aero Gear. All gears were surface temper etch inspected and magnetic particle inspected after the completion of machining. Scuffing tests of asymmetric gear specimens and baseline specimens were conducted on a gear research test stand. Scuffing resistance was significantly increased for the asymmetric tooth gears compared to a traditional symmetric involute tooth design.
