Jixie chuandong (Apr 2022)
Analysis of the Influence of Clutch Drag Torque on the Efficiency of Hydro-mechanical Continuously Variable Transmission
Abstract
In order to study the influence of multiple clutches on the transmission efficiency of a hydro-mechanical continuously variable transmission （HMCVT），the structure characteristics of a closed loop consisting 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 model 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 derived. The calculation results show that the band and row loss of multiple friction clutches in HMCVT has a great influence on its transmission efficiency.
