拖拉机液压机械无级变速传动系统速比匹配策略

为实现发动机的最佳动力性和燃油经济性,提出了拖拉机液压机械无级变速传动系统速比匹配策略。利用发动机试验测试结果,采用多项式拟合方法建立了发动机模型。根据发动机的转速调节特性,在拖拉机液压机械无级变速传动系统确定的速比范围内,给出了实现发动机最佳动力性和最佳经济性工况运行时的目标速比。对装备液压机械无级变速器后的拖拉机与原拖拉机的牵引性能进行比较,结果表明:装有液压机械无级变速器后拖拉机在任何牵引力时,发动机都在接近于满负荷点工作,拖拉机生产率和燃油经济性有所提高。本研究所提出的速比匹配策略是合理的。

Speed ratio matching strategies of hydro-mechanical continuously variable transmission system of tractor

To realize the optimal power and the best fuel economy performance of an engine,the speed ratio matching strategies of a tractor with hydro-mechanical continuously variable transmission(HMCVT) system were studied.The engine output torque model and fuel consumption model were established based on the engine test results.On the basis of the engine rotary speed feature,the target speed ratios of HMCVT system in the numerical table were given,which realized the optimal power and the best fuel economy performance within the speed ratio range of the HMCVT system.The tractive performances from the tractor equipped with HMCVT and the original tractor were compared.The results showed that a tractor assembled with HMCVT could gain a continuously variable speed and the engine worked near full load under any traction load.As a result,the tractors with the HMCVT would improve themselves productivities and fuel economies.The speed ratio matching strategies are reasonable.