采棉机动力换挡行驶传动系统设计与试验

Design and Test of Power Shift Driving Transmission System of Cotton Picker

针对采棉机作业工况复杂,提出一种由静液压无级变速与机械式有级变速组配式动力换挡无级调速行驶传动方案。建立采棉机田间采摘、田间运输和公路运输3种工作模式控制逻辑,确定3种模式速度范围。构建动力传动方程,确定采棉机设计参数和液压系统元件选型。搭建采棉机样机进行速比特性田间试验,分析调速特性与变量泵效率特性。结果表明:通过变量泵和变量马达联合调控以及改变机械式有级变速箱传动比,可实现采棉机在田间采摘模式时恒转矩输出,在运输模式时恒功率输出;采棉机田间采摘速度范围为0~8.5 km/h,田间运输速度范围为0~14.5 km/h,公路运输速度为0~27.5 km/h;可实现采棉机全程作业无级调速,满足其行驶动力需求。

Aiming at the complicated working conditions of the cotton picker,a power shift stepless speed regulation driving transmission scheme with a combination of hydrostatic continuously variable transmission and mechanical step transmission was proposed.The control logics of three working modes of the cotton picker,such as field picking,field transportation and road transportation were established,and the speed ranges of the three modes were determined.The power transmission equation was construct,and the design parameters and hydraulic system components selection of the cotton picker were determined.A cotton picker prototype was built for field test,and the speed regulation characteristics and variable pump efficiency characteristics were analyzed.The results show that through the joint regulation of variable hydraulic pump,variable hydraulic motor and changing the transmission ratio of mechanical stepped gearbox,the constant torque output of the cotton picker in the field picking mode and the constant power output in the transportation mode can be realized;the field picking speed range of the cotton picker is 0~8.5 km/h,the field transportation speed range is 0~14.5 km/h,and the highway transportation speed is 0~27.5 km/h;the whole operation of the cotton picker can realize stepless speed regulation to meet the driving power demand of the cotton picker.