Publication

Abstract : The aim of asymmetric tooth is to improve the performance of gears such as increasing the load capacity or reducing noise and vibration. Application of asymmetric tooth side surfaces is able to increase the load capacity and durability for the drive tooth side. The tooth form has left-right symmetry in the involute cylindrical gear, and the same performance can be obtained at forward and backward rotation. However, both the forward and backward rotations are not always expected in the practically used gear units for power transmission. Therefore, two sides of the gear tooth are functionally different for most gears. Even if one side (drive side) is significantly loaded for longer periods, the opposite side (coast side) is unloaded or slightly loaded for short duration only. In several papers , the higher pressure angle profile for the drive side and lower pressure angle profile for the coast side have been considered. This kind of application makes it possible for the gear to reduce the bending stress. The asymmetric involute tooth can be manufactured by the same process as in generating the symmetric involute tooth. Asymmetric profile is achievable by adopting the different pressure angle values of coast side and drive side of the bevel gear for the two sides of the rack. Depending on the special tooling, production cost of these gears increases. Therefore, the gears with asymmetric teeth should be considered for gear systems that require extreme performance like aerospace applications and for mass production, where the share of the tooling cost per one gear is insignificant. The most promising application of asymmetric profiles seems to be in molded gears and powder gears. In this study, asymmetric spur bevel gear with higher drive side pressure angle than coast side pressure angle has been considered. The purpose of this study is to determine bending load carrying capacity and the dynamic characteristics of asymmetric bevel gear.