The impact and vibration of helical gear will inevitably occur in the process of transmission meshing, which will increase the contact stress of helical gear and cause the stress concentration on the contact surface of gear teeth. According to the research on the dynamic and static contact stress of helical gear in the previous chapters of this paper, it is found that the helical gear is easy to produce excessive contact stress at the meshing in and meshing out position of gear teeth, and the phenomenon of stress concentration is serious. In order to reduce the meshing impact of helical gear, improve the load distribution, eliminate the phenomenon of stress concentration, reduce vibration and noise, and significantly improve its bearing capacity, transmission accuracy and service life, the basic starting point of helical gear modification is to make the tooth surface pressure distribution of helical gear after load deformation as uniform as possible, while still maintaining stable operation and reducing impact. At present, the research on helical gear modification at home and abroad has developed from static modification to dynamic modification. Therefore, this chapter mainly studies the influence of different modification methods on the dynamic contact stress of helical gear in the two end supported helical gear model with simultaneous meshing of four gear pairs of teeth in transmission helical gear.

Based on the principle of helical gear modification, this paper introduces different modification methods of helical gear, determines the modification parameters of helical gear profile modification and drum modification, and solves the helical gear models after different modification by using the finite element dynamic contact analysis method. Through comparative analysis, it can be known that the appropriate modification design of helical gear can effectively improve the phenomenon of stress concentration, and due to the reduction of load impact, The stress of the meshing tooth surface also tends to be stable, which can effectively improve the contact strength of the helical gear and prolong the service life of the helical gear.