关键词: 拖拉机, 无级变速箱, 功率分流, 仿真, AMESim

Abstract: In order to adapt to the complex working conditions of the tractor and improve its working efficiency, a design scheme of tractor hydrostatic power split CVT (Continuously Variable Transmission) was proposed in this paper. Firstly, the transmission principle of the CVT was introduced.Then, according to the parameters of the engine and rear axle, as well as the speed requirements of the tractor, the transmission parameters and structure of the CVT were designed. Finally, the simulation model of the CVT was built under AMESim, and its speed regulation characteristics were analyzed. The research results show that the transmission can realize the stepless speed regulation of the tractor in the range of 0-30 km/h, and has small hydrostatic splitting power under key working conditions such as ploughing to save energy. The ratio of pump to motor displacement of the transmission needs to be quickly modulated from 1 to -0.85 during shift to ensure that the tractor has the same driving speed before and after shift. It has a certain reference value for the domestic application of CVT tractors in China.

Key words: tractor, continuously variable transmission, power split, simulation, AMESim