Influence of using Asymmetric Teeth Profile on Stress Concentrations in Gear Key-way

Abstract

The key is a machine element that transmits power from shafts to pulleys, gears, and vice versa. A case study shall be conducted in this paper to investigate the influence of using gears with asymmetric teeth profile on stress concentrations in gear key-way, employing the theory of elasticity represented by the stress function method. Then, the obtained results are verified by FEA. The final object is to select the best shape of the key-way that achieves the minimum stress concentration. The outputs demonstrate that stress tolerance is substantially increased as the mechanism switches from normal to irregular. It also shows that the circular key-way is the safest, more appropriate, and subjected to the minimum stress when the same force is applied. For the asymmetric gear with circular arc key-way, the percentage of improvement approaches 38 % relative to the regular one of flat key-way in the numerical results, whereas, in the analytical investigation, the same percentage is almost 6 %. The percentage is also nearly 15% when going from the regular 14.5° spur gear to the 14.5°-20° asymmetric spur gear.