特性参数连续可变液压机械复合传动的分流机理及控制方法

Hydro-mechanical continuously variable transmission (HMCVT) has a key design variable of planetary ratio which directly affects many transmission performances such as the speed ratio range, efficiency, power and so on. However, the normal planetary gear train always has a constant planetary ratio that cannot be changed while working. To solve the problem, this project proposes a traction power split architecture with variable planetary ratio. In order to investigate the interaction nonlinear relationship between the rotation speed and torque, this project present an iteration and recursion method which is on the basis of dynamics theory and elasto-hydrodynamic lubrication theory. The graph theory will also be utilized in this project to search all of the configurations of the traction power split HMCVT. The operating conditions of hillside tractors are then taken into consideration to conduct a comprehensive comparison of all the feasible configurations. Then, a HMCVT configuration with excellent comprehensive performance will be selected. A systematic control method suitable for the HMCVT is proposed. The control method consists of a double variables control method, a selection strategy for the planetary ratio and a multi-model shifting method. At last, experimental test will be performed whose experimental data can offer the recursion method with corrections. This project will propose an integrated theory of the schematic design, dynamics analysis and control method for the traction power split HMCVT. Utilizing the interaction method, which is used to solve the problem of the interactive relationship between parameters, can provide new ideas to other similar problems. The proposed traction power split HMCVT has an extensive application prospect on low-powered hillside tractors and other hillside agricultural machineries.

液压机械复合传动（HMCVT）中行星排的特性参数是关键设计变量，影响传动比范围、效率、功率等传动性能。针对现有齿轮行星排特性参数固定，不能在传动中变化的困难，本项目提出牵引式分流传动方案实现特性参数连续可调。针对牵引式分流传动中转速与扭矩相互影响，非线性关系不明确的问题，本项目拟采用动力学及弹性流体动力润滑理论，通过迭代递归方法探明牵引分流机理。利用图论理论对牵引分流HMCVT完成方案搜索，结合丘陵山地拖拉机工况，综合比较后提出优秀传动方案；提出牵引分流HMCVT的双参数控制方法、特性参数选择策略与变模式方法。最后完成样机试制与实验研究并结合实验数据修正理论模型。本项目创新地构建出一套针对牵引分流HMCVT从方案设计、动力学分析到控制方法的完整理论，利用迭代法解决参数间的纠缠关系，对其他类似问题的解决提供思路；所提出的牵引分流HMCVT在小型丘陵山地拖拉机与其他丘区农机上应用前景广泛。

液压机械复合传动（HMCVT）中行星排的特性参数是关键设计变量，影响传动比范围、效率、功率等传动性能。针对现有齿轮行星排特性参数固定，不能在传动中变化的困难，本项目提出一种牵引式分流传动方案实现特性参数连续可调。针对牵引式分流传动中转速与扭矩相互影响，非线性关系不明确的问题，本项目采用动力学及弹性流体动力润滑理论，通过迭代递归方法探明牵引分流机理。对牵引分流HMCVT完成方案搜索，结合丘陵山地拖拉机工况，综合比较后提出优秀传动方案；提出牵引分流HMCVT的双参数控制方法、特性参数选择策略与变模式方法。.本项目提出的牵引分流HMCVT传动系统可实现特性参数连续可调；并构建了针对牵引分流HMCVT从方案设计、动力学分析到控制方法的完整理论，提出了一套基于EHL牵引行星排的转速与扭矩分布的计算方法，并解决了参数间的纠缠关系。提出了一套先穷举优化再基于评价指标选型的行星比连续可变复合传动优化选型方法，并结合NSGAⅡ多目标优化程序优选出一套实现宽速比、大扭矩的优秀方案。项目结合拖拉机工况，结合参数循环算法优化得到发动机和HMCVT最佳工作点区间，提出了牵引分流中HMCVT排量比和特性参数协同控制的双参数控制方法与控制策略。本项目根据改造的特性参数连续可调牵引行星排，结合机械设计手册和建模辅助工具完成了样机的设计与加工工作。本项目的研究对牵引分流HMCVT中变速器的开发及应用以及改善拖拉机燃油经济性均起到了推动作用。