On the Behaviour of Asymmetric Cylindrical Gears in Gear Transmissions

Asymmetric gears have been proposed more than twenty years ago as the ultimate solution to increase the load capacity of gear drives while reducing their weight and dimensions. However, there are apparently contradictive statements in the literature regarding whether the higher pressure angle should be applied to the driving or coast side of the gear tooth surfaces. In this work, modern technologies of design and analysis of enhanced gear drives will be applied in order to validate the advantages of application of asymmetric gears and to determine what the right configuration of the asymmetric gear drive should be in terms of application of the higher pressure angle to the driving or coast side of the gear teeth. The evolution of contact and bending stresses as well as contact pressure for the whole cycle of meshing is investigated and compared for symmetric and asymmetric gears. Two configurations of asymmetric gears will be considered, taking into account both, the higher and the lower pressure angle for the driving side. In this way, the advantages of application of asymmetric cylindrical gears as well as the right configuration to get them are established.