17.9.2013 Pressing & Sintering

Optimizing the Tooth Root Strength of Sintered Gears for a Manual Automotive Transmission

Tooth root bending fatigue is one of the failure mechanisms of gears. Thus by decreasing the stresses in the tooth root the strength of the gears can be increased. Here the PM technology is more flexible than traditional machining of gears, since the tooth root can be designed into whatever shape desired. In this paper it’s investigated how the tooth root of PM Gears can be optimized to reduce stresses. By two different methods, using a CAD software and a gear design software it’s demonstrated that bending stresses can be decreased with as much as 30% for gears in a six speed automotive gearbox.