混合式液压-机械无极变速分流理论与基本特性研究

With the rapid development of science and technology and the urgent demand of industry, national defense, and the people's livelihood, there is a growing emphasis on high efficiency and emission reduction of operating vehicles or special vehicles, while the number of operating vehicles or special vehicles is growing with the increasingly wide range of applications. Operating vehicles with a low walking speed and high operating speed, high power density, in most cases, employ a single mechanical drive with poor speed governor and heavy power consumption, or hydraulic drive way with poor efficiency and high cost. If HMCVT (Hydro-mechanical Continuously Variable Transmission) is adopted, this problem could be solved. This project is focused on key scientific issues that obstruct the promotion of HMVCT ,such as internal coupling match, power recirculation and energy recovery. Based on loating lever principle, power split theory of all kinds of splitter and speed regulator theory of HMCVT will be systematically studied; its physical-mathematical model will be established; its load and efficiency characteristics will be explored; initial conditions and internal mechanism of the power recirculation will be analyzed; a set of Hydro-mechanical Continuously Variable Transmission design methods and theory with high-performance, high efficiency, high reliability, and adaptability will be proposed, which will be developed and be promoted as soon as possible in our country, creating enormous social and economic benefits.

着科技的飞速发展和工业、农业、国防、民用的迫切需求，工程、农机、环卫、军事等领域的各种作业车辆或特种车辆的应用越来越广，对车辆的高效率、低排放要求也越来越高。这类车辆具有行走速度低和工作转速高、功率大的特点，目前采用单发动机加机械传动或液压传动、或直接用多个发动机的方案来满足工况，前者调速性能差、功耗大，后者效率低、排放高、造价高。而采用混合式液压机械复合传动就能较好的解决这一难题。本项目重点研究和解决影响当前混合式液压机械无级变速器中机械传动与液压传动内在耦合匹配、功率循环和能量回收等关键科学问题。力求从"浮动杠杆原理"出发，研究混合式液压机械复合传动的调速和功率分流机理、建立其物理数学模型，深入探索其负载、效率等特性，剖析功率循环机理和能量回收方法，提出一套高性能、高效率和适应性强的液压机械无级变速器的设计方法和理论，最终实现其加速发展和推广应用，为国家创造巨大的社会价值和经济效益。

液压机械复合传动是解决作业车辆的高效率、低排放的要求的一种有效途径。针对传统的纯机械（液压）传动方式调速性能差或功耗大以及输入、输出耦合式液压机械复合传动存在的调速范围窄或传动效率相对偏低的不足，本课题采用混合式液压机械复合传动方案。在研究分析48种液压机械复合传动模式的效率、功率分流等工作特性基础上，根据多模式下液压复合传动的内在耦合匹配关系，提出了模式优先方法和基于遗传算法的参数优化方法；研究了液压机械复合传动的功率循环内在机理，提出了功率循环的产生判据和抑制方法；提出和设计了液压机械复合传动系统的制动能量回收优化方案和制动力分配控制策略，有效提升了系统效率；通过模拟仿真对其静动态工作特性进行了验证，提出了变论域模糊PID的速比跟踪控制策略；设计制造出复合变速器样机，通过综合性能试验研究，有效验证了液压机械无级变速器的设计方法和理论。课题的研究对于混合式液压机械复合变速器的加速发展和推广应用提供了理论方法和技术支持。