同步器同步机理建模与结构影响因素分析

Synchronization mechanism modeling and structural effect factors analysis of synchronizer

针对同步器结合过程,利用平均雷诺方程和微凸体摩擦原理,建立了油膜压力、微凸体接触力、同步环轴向力、同步力矩4个数学模型,运用4-Runge-Kutta法对油膜厚度和转速差进行耦合数值求解,分析了同步器结合过程油膜厚度、转速差、粘性剪切转矩、粗糙摩擦转矩以及总转矩的变化规律.对同步器结合过程数学模型进行试验验证后,利用所建模型研究了同步环宽度、同步环半径、摩擦锥角以及摩擦材料厚度等因素对同步器结合过程的影响规律.结果表明:同步环宽度增大,粘性转矩和粗糙接触转矩增大,油膜厚度下降速率减缓,粗糙接触转矩响应延迟,同步时间增加;同步环半径增大,粘性转矩和粗糙接触转矩增大,油膜厚度下降速率加快,同步时间缩短;同步环摩擦锥角增大,粘性转矩增大,粗糙接触转矩减小,转速差下降速率变缓,同步时间增加;摩擦材料厚度增大,粗糙接触转矩相应加快,油膜厚度下降速率增大,最小油膜厚度减小,同步时间缩短.

Four mathematical models of oil film pressure, contact force of asperity, axial force of synchronizer ring and cone torque are established by means of average Reynolds equation and asperity friction principle. The coupling number of oil film thickness and speed difference of synchronization is solved by using 4- Runge-Kutta method. The changing rule of oil film thickness, speed difference, viscous torque, asperity friction torque and total torque are analyzed. After verification of the mathematical model of synchronization, the effects of structure factors such as the width of synchronizer ring, radius of synchronizer ring, cone angle and thickness of friction material of synchronizer are studied by the model. The results show that the increase of the width of synchronous ring results in increasing viscous torque and asperity friction torque, decreasing the decline rate of oil film thickness, the response of asperity friction torque is delayed and the synchronization time is increased. With the increase of the radius of synchronous ring, the viscous torque and asperity friction torque increase, the oil film thickness descends and the synchronization time is shortened. When the friction angle increases, the viscous torque increases, the asperity friction torque decreases, the speed difference descends slowly and the synchronization time prolongs. With the increase of friction material thickness, the asperity friction torque and the changing rate of oil film thickness increase correspondingly, but the minimum oil film thickness and the synchronization time decrease.