电动拖拉机传动系设计理论与方法研究

Study on design theory and method for driving line of electric tractor

基于电驱动的特点,提出了一种电动机和变速箱协同调速的电动拖拉机传动系统结构方案。在对电动拖拉机牵引特性进行理论分析的基础上,提出了电动拖拉机动力性评价指标及其计算公式;并对电动拖拉机动力传动系统各部件主要参数的设计理论和计算方法进行了探讨,提出了一套电动拖拉机驱动系统设计理论和计算方法。以某电动拖拉机为研究对象,通过计算分析了不同工况、不同档位下的驱动力和爬坡度与速度的关系以及不同工况下一次充电连续作业时间与速度的关系。分析表明,不同档位下驱动力随速度增加而下降,其变化趋势与电动机输出特性一致;不同档位下爬坡度随速度增加而迅速减小,例如在第Ⅴ档作业时,当速度达到15 km.h-1时,爬坡度不足1%;一次充电连续作业时间随速度增加而下降,而且作业工况对它具有较大影响。

Taking the characteristics of electric tractor （ET） into account, a new type of structure scheme that cooperating variable speed concerning motor and gear for driving line of ET was put forward. Evaluation index and its calculation model for dynamic performance of ET were suggested, based on the theory analysis of traction characteristics of ET. The parameter design theory and calculation method of each component of driving line of power train were discussed, and a set of theory of design and calculation method for driving line of power train of ET were proposed. Taking an ET as study object, the relationship between the speed and driving force and climbing property under different work conditions and different gearshift, and the relationship between the speed and continuous working time under different work conditions were analyzed by calculating. The analysis showed that the driving force under different gearshift decreased with the increasing of speed, and that the trend of changing was consistent with output characteristics of motor; the climbing property under different work conditions decreased quickly with the increasing of speed, for example, the climbing property was under 1% when the speed reached 15 km.h^-1 under the fifth shift; the continuous working time decreased with the increasing of speed, and work conditions had significant effects on it.