关键词: 液压机械无级变速器；无级调速特性；扭矩特性；AMESim

Abstract: Hydro-mechanical continuously variable transmission has the advantages of high efficiency and stability, and the domestic research on this technology started late. CASE's PUMA four-segment hydro-mechanical continuously variable transmission is taken as the research object in this paper, and its continuously variable speed regulation, torque characteristics, and hydraulic power shunt ratio are analyzed. The relationship between the input-output speed ratio of PUMA transmission, the hydraulic power shunt ratio and the displacement ratio of variable pump and fixed motor, and the relationship between the torque of the output shaft of the transmission and the output shaft of the motor are given. In the end, based on AMESim software, the simulation model of PUMA transmission is established, and the relationship between its input speed and output speed is simulated and analyzed. The results show that the transmission can realize the continuously variable of the whole speed range of the tractor. The purpose of this study is to provide a reference for the theoretical research and design of stepless transmission.

Key words: Hydro-mechanical continuously variable transmission; Continuously variable characteristics; Torque characteristics; AMESim