Load distribution and tooth fillet stress of straight bevel gears using a stiffness variation technique

A closed–form solution is presented to evaluate load distribution and fillet stresses during single and double tooth contact of straight bevel gears. The procedure outlined is based upon the assumption that the bevel gear can be approximated by an equivalent spur gear using the well known Tredgold principal, and that meshing teeth deflections along contact lines(s) are inversely proportional to stiffnesses, and are determined in such a way so as to avoid interference and physical overlap between mating teeth. Moreover, load distribution is taken to be inversely proportional to stiffness variation along contact line(s). Finally, fillet stress distribution at both tensile and compressive sides of the tooth was determined from contact load and tooth geometry. The results were compared with those obtained experimentally using strain gauge (SG) measurements; and numerically using Finite Element Method (FEM). Good correlation between all these results was found.