Search method applied for gear tooth bending stress prediction in normal contact ratio asymmetric spur gears

Abstract

Various analytical methods have been developed by designers to predict gear tooth bending stress in asymmetric spur gears with an intention to improve the accuracy of predicted results and to reduce the need for time consuming finite element analysis at the early stages of gear design. Asymmetry in the drive and coast side of asymmetric spur gears poses difficulty in direct application of well-known procedures like American Gear Manufacturers Association and International Organization for Standardization in the prediction of gear tooth bending stress. In earlier works, ISO-6336-3 methodology was suitably modified and adapted to predict asymmetric spur gear tooth bending stress. This approach is based on certain assumptions on the location of critical section which could introduce error in the predicted maximum bending stress. The present work is to analytically predict gear tooth bending stress in normal contact ratio asymmetric spur gears based on a more rigorous analytical approach. This includes a fundamental study on the gear tooth orientation used to define the coordinate system, determination of maximum bending stress by search along the fillet profile and to obtain stress profile along the fillet. Gear tooth bending stress obtained from the present work using Search method is compared against the results obtained from earlier adapted International Organization for Standardization method and Finite Element Analysis. This study recommends a new coordinate system and method for analytical prediction of gear tooth bending stress in normal contact ratio asymmetric spur gears.

Experimental and numerical investigation of the bending fatigue performance of symmetric and asymmetric polymer gears

“…Cavdar et al 12 determined the form factor and the stress correction factor of an asymmetric gear by utilizing the method for nonstandard symmetric gears developed by Pedrero et al 13 Sekar and Muthuveerappan 14 calculated the form and the stress correction factors by employing a modified ISO B framework and compared the results of the FEM and analytical methods. Thomas et al 15 presented an approach based on a search method to calculate the bending stress in an asymmetric gear and observed that the results closely agreed with the FEM results. Mo et al 16 defined a composite bending stress formula for an asymmetric gear by incorporating the effects of friction, compressive stress, and shear stress in the Lewis bending stress equation.…”

“…Thomas et al. 15 presented an approach based on a search method to calculate the bending stress in an asymmetric gear and observed that the results closely agreed with the FEM results. Mo et al.…”

A Review on Bending Strength of Asymmetric Gear

“…Increasing the amount of relief can smooth the variation in shared loads and contact stresses during gear meshing, but the loaded contact ratio will be reduced. Benny Thomas et al [28] predicted gear tooth bending stress in normal contact ratio asymmetric spur gears based on Search Method analytical approach. This study recommends a new coordinate system and method for analytical prediction of gear tooth bending stress in normal contact ratio asymmetric spur gears.…”

Calculating the Load Distribution and Contact Stress of the Disposable Harmonic Drive under Full Load

“…Vivet [3] analyzed the contact characteristics of face-milled spiral bevel gears based on the beam theory and the Hertz contact theory. Thomas et al [4] proposed a new coordinate system and search method to predict the tooth root bending stress in asymmetric spur gears. Using the Hertz contact principle and a finite element model (FEM), Mohammed et al [5] determined the influence of rotational speed on the contact stress of spur gears.…”