Linear shape modification is adopted with the amount of 0.022mm. The value range of the length of the modification is [1.4mm, 8.4mm], and the interval between the values is 1.4mm.The average engine torque of 2500N.m is applied to gear 1. The influence of modification length on meshing stiffness and load distribution coefficient between teeth is shown in the figure.It can be seen from the diagram that the increase of the modification length does not affect the meshing rigidity of the single-tooth meshing area, while the overlap degree of the gears remains unchanged, but the proportion of the time occupied by the double-tooth meshing area gradually decreases.
When the modification length exceeds 4.2mm, the double-tooth meshing area is all in the modification area. The modification of the tooth profile significantly eases the sharp change of the meshing rigidity of the gear produced when the single-tooth and double-tooth engagement alternate.It can be seen from the drawing that when the profile modification length exceeds 4.2mm, the profile modification realizes a smooth transition of gear load variation.
The influence of the modification length on the amplitude corresponding to the first five meshing frequencies of the meshing stiffness is shown in the figure.It can be seen from the graph that the modification length also has a great influence on the corresponding amplitude of each meshing frequency.Compared with gears without modification, when the modification length is 1.4mm and 2.8mm, the corresponding amplitude of first-order meshing frequency increases, and when the modification length is more than 4.2mm, the corresponding amplitude of first-order meshing frequency significantly decreases.