2022 46 4 63 年 第 卷 第 期 ， ， ） 3 State Key Laboratory of Power System of Tractor Luoyang 471003 China （ ， ， ） In order to study the influence of multiple clutches on the transmission efficiency of a hydro- Abstract mechanical continuously variable transmission HMCVT the structure characteristics of a closed loop consist⁃ （ ）， ing of multiple wet friction clutches in the transmission are investigated. The influence of clutch drag torque on the efficiency characteristics of hydro-mechanical CVT is analyzed. By analysis and calculation of the drag torque generated in the clutch disengagement stage which affects the transmission efficiency a calculation mod⁃ ， ， el for power transmission in the clutch disengagement stage in a closed loop is established a calculation formula ， for power loss caused by clutch drag torque in closed transmission is deduced and a calculation method for the total efficiency of the transmission system is further
