Abstract
Under the considerations that many power transmission gears run practically in one rotational direction, the dimensions of the front side (loaded side) and backside (unloaded side) of the tooth might be designed individually. In this research, a new kind of involute gear was developed, where the standard pressure angles of the front side and backside of the tooth were different. The maximum tensile tooth fillet stress was calculated by two-dimensional FEM. Increasing the standard pressure angle of the backside of the tooth from 20deg to 35 deg decreases the maximum tensile tooth fillet stress about 20% and increased the stiffness of tooth due to the increased critical section. Bending fatigue tests were performed for two types of normalized and induction-hardened gears to evaluate the enhancement in bending load carrying capacity using different backside standard pressure angle. The pressure angles of the front side/backside of the tooth of test gears were 20/20deg and 20/30deg. The fatigue test results confirmed the significant increase in bending load capacity by the use of a larger backside pressure angle of the tooth.
