关键词: 无同步器；自动变速器；换挡冲击；换挡过程

Abstract: Due to the simple mechanism and high mechanical efficiency of synchronizer-less mechanical automatic transmission, it can improve energy utilization efficiency and range in electric vehicles. In order to promote the application of synchronizer-less mechanical automatic transmission to electric vehicles, focusing on its problems of shift shock and power interruption, a dynamics model of the engagement sleeve and engagement gear ring is established to investigate the shift shock mechanism and the factors affecting the shift quality. Simulations were conducted in AMEsim to analyze the changes of shift shock, shift time and other shift quality indicators under different initial speed difference and shift force conditions. The results show that the larger the initial speed difference between the engagement sleeve and the engagement ring, the longer the shift time and the larger the shift shock; the larger the initial shift force, the shorter the shift time, but the shift shock becomes larger. When the initial conditions of the shift process are high shift force and low speed difference, both shorter shift time and lower shift shock can be obtained and the shift quality is improved.

Key words: Synchronizer-less; Automatic transmission; Shift shock; Shifting process