Study Of The Crowning Gear Coupling Used On The High Speed Train

The crowning gear coupling is widely used in the transmission system of high speed EMU. Because of its important role in the process of transmission, it is necessary to conduct comprehensive and in-depth research on the meshing characteristics, stress and vibration characteristics of the crowning gear coupling. This paper aims at studying the crown gear coupling from the above aspects by the method which combined the theoretical calculation with and software simulation.In order to studying about the meshing of the crown gear coupling, this paper makes a comparative analysis on three kinds of calculation methods, and presents the modified geometric algorithm according to the processing principle of the crowning gear. The research shows that:the correction improves the calculating speed and precision.In this paper, the crowning gear coupling is analyzed on the meshing, the interference,the movement and the teeth load by the geometric correction algorithm. The conclusions shows below:1) as the misalignment angle increases, the clearance between meshed tooth of each tooth is reduced, the position where the minimum clearance occurs deviate to the edge of the teeth surface, and moves from the tip to the root of teeth. When the tooth rotates from the turning area to the swaying area, the position of the minimum clearance concentrates to the center tip of the teeth.2) The interference analysis of the crowning teeth showed that as the misalignment angle increases, the tooth surface curvature interference become worse and the back contact interference is influenced by the crowning radius of tooth surface and the inner gear tangential displacement3) The analysis of the movement between internal and external tooth shows that relative sliding rate of the tooth surface is caused by the relative swaying between internal and external teeth.4) The calculation result of crowning gear tooth load shows that the tooth surface tends to contact at the turning area and the load of the teeth here is significantly greater than the load of the other teeth. The relative stress coefficient of tooth surface is mainly affected by the misalignment angle and the input torque.5) The analysis of additional torque coupling shows that the additional torque (including restore torque, friction torque) increases with the misalignment angle and the variation law is mainly influenced by the distribution of the contacted teeth, and the deflection torque can be ignored.In this paper, the crowning gear is optimized further, it is found by calculating that a larger pressure angle and a smaller module gear can effectively solve the problem of the edge contact and interference. The study come up with the optimization method for tooth surface of arbitrary crowning curve according to the external tooth profile.Multi body dynamics model of the gear coupling and the motor vehicle with the crowning gear coupling are built at the end of this paper and the vibration characteristics of coupling is analyzed on the condition of cyclic excitation. It is shown by the spectrum curve study that the external force reach to the peak at the odd harmonic of excitation frequency,the deflection gear acceleration of internal gear is generated by the gyroscopic force and the vertical vibration acceleration increases with the running speed, the frequency response of which is sensitive to the rotation.