摘要
Aim To determine efficiency of multi-range hydro-mechanical stepless transmis- sion(HMT).Methods Ageneral model of HMT was of HMT was structured.On the basis of power flow analysis, the efficiency was obtained,Results efficiency of multi-range HMT changes continuously with output speed in speed range and is higher than the highest point of the hydraulic efficiency,The volumetric efficiency can potentially result in the speed fluctuation, which can be reduced or eliminated through controlling the ratio of the displacements ofhydraulic unity properly or changing the point of range exchanging .And the mechanical- constant output torque or different output torque under the condition of constant pressure when the transmission works in different parts of a range,Conclusion The multi-range HMT is an ideal stepless transmission with high efficiency.
研究多段液压机械无级传动的效率问题。方法在建立构造模型和分析功率流程的基础上，推导了效率计算的一般公式。结果多段液压机械无级传动的效率是分段连续的，在较大的范围内高于液压传动的最高效率；液压传动的容积效率能引起输出转速跳动，但可通过控制液压元件排量比或调整换段点的办法使其减小或消失；液压元件的机械效率会引起液压元件的工作压力或输出转矩的变化。结论多段液压机械无级传动是一种比较理想的高效率无级传动装置。
