Multi-Range Hydro-Mechanical Continuously Variable Transmission of Tractor
In this paper, to improve the transmission ratio discontinuity problem during the gear shift process in the multi-gear fixed step ratio transmission of the tractors, a hydro-mechanical continuously variable transmission (HMCVT) for tractors is developed, which is composed of a single planetary gear differential train, a hydraulic transmission system consisted of the variable displacement pump (PV) and the fixed displacement motor (MF) and a multi-gear fixed step ratio transmission. Its stepless-speed-regulating characteristic, smooth range shifting condition and transmission efficiency are analyzed. The analytical results show that the tractors assembled with HMCVT can gain wide speed range and high transmission efficiency. There are eight high efficiency pure mechanical gears in the whole speed range, which is benefit to improve power and economic capabilities of vehicles.
Dongming Guo, Jun Wang, Zhenyuan Jia, Renke Kang, Hang Gao, and Xuyue Wang
L.Y. Xu et al., "Multi-Range Hydro-Mechanical Continuously Variable Transmission of Tractor", Materials Science Forum, Vols. 628-629, pp. 167-172, 2009