Effect of Rim Thickness on Symmetric and Asymmetric Spur Gear Tooth Bending Stress

摘要

Thin rim gears find application in high-power, lightweight aircraft transmissions. Bending stresses in thin rim spur gear tooth fillets and root areas differ from the stresses in solid gears due to rim deformations. Rim thickness is a significant design parameter for these gears. The rim thickness factor is used in the situations in which a gear is made with a rim and spokes rather than a solid disc. Under these circumstances, failure can occur across the rim rather than through the tooth root. An asymmetric spur gear drive means that larger and smaller pressure angles are applied for the driving and coast sides. The two profiles of a gear tooth are functionally different for most gear drives. The workload on one side of profile is significantly higher than the other Gears. The main objective of this paper is to estimate the critical section for different pressure angles and backup ratios using computer programme and compare the results obtained by other researchers. Developed programme is used to create a finite element model for symmetric and asymmetric spur gear tooth to study the effect of bending stress at the critical section for different backup ratios. To study the effect of above parameter ANSYS was used. The rim thickness was varied and the location and magnitude of the maximum bending stresses were reported and results obtained were compared with the Lewis bending equation.