AGMA 97FTM6 PDF

The bending strength geometry factor J depends on the location of the critical section and the tooth thickness at this section. The critical section is that in which the uncorrected bending stress, given by Navier'sequation, is maximum and consequently it is defined by the point of tangency of the Lewis Parabola and the tooth profile. This point of tangency is usually placed over the root fillet, but in some casts the tangency may occur at the involute. For these cases the methods descriied in literature for determining the AGMA J-factor are not suitable. This paper presents the condition for tangency at the involute and a method to determine the J factor under this condition.