Characteristics of the Hydro-Mechanical Continuously Variable Transmission in the Wheeled Tractor

Based on the hydro-mechanical continuous variable transmission (HMCVT) of 400 house-power of Dongfanghong, the synchronization in period of contions to content to multiple period of HMCVT was established by analyzing its transmission principle, and the relation fomulas of power distributing ratio and efficiency was presented. That results showed that the characteristics of power flow at the first half and at the second half were different, when it was within the certain grade to do the boundary of e equaled with zero; while it was each grade in section points, that characters were the same; the more grades, the greater HMCVT system transmitting power and the higher the transmission efficiency of the entire system. The high efficiency features of multiple range hydro-mechanical stepless transmission, meet the requirement of tractor operation.