In the calculation of the two standards, the calculation service factors of the two factors are involved. In the international standard, Ka is used, and in the American Standard, Ko is used. Because the life under the load spectrum is calculated, Ka = 1 and Ko = 1 can be taken. The tooth load distribution coefficient is KH β in international standard and KM in American Standard.
Generally, after the calculation of the basic life of the gear, the micro repair design of the gear will be carried out according to the installation rigidity conditions of the gear, and the tooth direction of the gear will be modified. The purpose of profile modification is to eliminate the influence of the bending and torsion deformation of the shaft on the gear meshing, so as to obtain a more uniform axial load distribution. The results show that the tooth profile modification can reduce the peak value of the bending stress of the tooth root and the contact stress of the tooth surface, and transfer the peak value from the edge to the middle of the gear, which is more conducive to the improvement of the bearing capacity of the tooth surface.
Therefore, KH β can be taken as 1.05, and the correlation coefficients in other standards can be obtained according to their respective standards.