Effect of Pressure Angle & Backup Ratio on Asymmetric Spur Gear Tooth

Thin rim gears find application in high-power, lightweight aircraft transmissions. Rim thickness and pressure angle are the 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 main objective of this paper is to estimate the critical section for different pressure angles and backup ratios 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 and pressure angle. To study the effect of above parameter ANSYS is used .The rim thickness was varied and the location and magnitude of the maximum bending stresses were reported and results obtained were compared.