【作者】 张博；

【导师】 梁锡昌；

【作者基本信息】 重庆大学 ， 机械制造及其自动化， 2004， 硕士

【摘要】 随着人民生活水平的日益提高和能源供给的相对紧张,人们越来越要求汽车乘坐舒适、节能省油、操纵简单,这样汽车变速箱和发动机就得更好的柔性配合,使发动机始终工作在最佳经济区域;但传统的齿轮变速箱只有几个固定速比,无法满足内燃机转速与车速之间的适时匹配,这就要求变速箱有足够的档位,当汽车档位无限多时即为无级变速。目前机械无级变速器(CVT)中大约可分为摩擦式、液力传动式、电磁传动式等几类,其中已实现装车量产的是摩擦式中的带式无级变速器。带式无级变速器上世纪六十年代量产以来,其关键部件——传动带V带由双橡胶V带过渡到VDT金属带,历经近二十年,虽然使用性能不断得到提高,但仍没有完全体现出无级变速在理论上的诸多优越性;经过全球技术工作者不懈的努力,到了2002年,汽车无级变速器带有了很大突破,一汽中国大众推出一款新型带式无级变速车:奥迪A6,改用的是多片链带,使奥迪A6成为了第一辆无论在动力性和燃油经济性都优于手动档的无级变速车[39],带式无级变速器迎来了新的发展高潮。目前已经装车使用的两种传动带无论是VDT金属带,还是大众的多片链带都存在着诸多问题:零件多,制造工艺复杂,成本高,导致装有无级变速器的车辆比手动档要贵,不利于更好的开发市场。于是有必要研究出一种新型V带,要求成本低廉、工艺简单、性能相当实用。针对此,申请了重庆市科委攻关项目“汽车无级变速器新型复合材料V带”(合同号6634),目的是提出一或几种种新型复合V带,较VDT金属带或大众的多片链带取材于廉价的材料、工艺简单、性能相当,以促进带式无级变速器的更快发展,加强本市汽车产业的竞争力。由于钢丝绳的柔性好,且为标准件,价格比环形带便宜,采用钢丝绳代替环形轧制环型钢带;金属片上铣有T型槽防止钢丝绳与金属片脱落,结构简单紧凑,命名为多片金属V带,并结合V带的结构特点,分析其在传动过程中金属快和钢丝绳组的运动学、力学关系,从宏观上分析了其传动机理,然后通过分析动力传递过程中金属快、钢丝绳和带轮的受力,推导求解金属快、钢丝绳的各种受力的数学解析式,并根据得到的数学解析式,推导出了V带的功率容量和制约其传动能力的因素,并用有限元分析软件进行了分析,为优化设计和试验做好了准备,然后进行了相应的性能试验与理论设计对比。但在对这种V带进行长期实验后,又发现了它的很多缺点,这些缺点有:(1) 一根V带要200~300块金属片,每块金属片有5个工作面,一共就有<WP=5>300(5=1500个工作面,为了保持这1500个工作面的精度,粗糙度,一致性,造成加工量很大,成本很高。(2) 金属片V带的重量较大,使用钢材较多。这些问题,在金属片V带的基础上,很难改进,为此只能另找出路,经过研究,提出柱绳式V带的新结构,并结合柱绳式V带的结构特点,分析其在传动过程中钢柱和钢丝绳组的运动学、力学关系,从宏观上分析了其传动机理,然后通过分析动力传递过程中钢柱、钢丝绳和带轮的受力,推导求解了钢柱、钢丝绳的各种受力的数学解析式,并根据得到的数学解析式,推导出了柱绳式V带的功率容量和制约其传动能力的因素,然后用有限元分析软件进行了分析,为优化设计和试验做好了准备,最后进行了相应的性能试验与理论设计对比。实践证明柱绳式V带是一个比较可行的。对无级变速器的低成本化和国产化都有一定的实际意义。更多还原

【Abstract】 With the development of the standard of living of our people and the relative lack of the energy supply, mankind come to ask for auto easy to control, comfortable to take, and have good economical property, so the gear box should cooperate with the engine well, lead the engine to always work in the most optimized area; but the traditional gear box only have some fix ratio, Cannot satisfy the timing cooperate between the rotate speed of engine and speed of the auto, which require gear-box have enough step, when the number of the step is infinity named continuous variable transmission (CVT).The continuous variable transmission (CVT) can be classified friction, fluid transmission, and electromagnetic transmission and so on, which implementation the assemble is the metal V-belt CVT.The key component V-belt change from rubber V-belt to VDT metal V-belt after the V-belt CVT implementation the assemble on the autos from 1960 last century, along the twenty years, though the performance come te be strengthened, cannot show the most of the merit of the performance of continuous variable transmission (CVT) in principle; with the continuous hard work of scientist all over the world, great break have taken place in Volkswagen China who develop a new V-belt continuous variable transmission (CVT) Multitronic CVT, which assemble the new metal path-chain V-belt; the auto which assemble such kind of transmission is better than the man-transmission no matter in the drive performance than the economic performance, Whether VDT metal V-belt or the path-chain V-belt which assembled on the autos have many problems: too many components, hard to manufacture, high cost, all of above lead the CVT cost more than man-transmission. So it is necessary to develop a new V-belt which have low cost, easy to manufacture and good performance. so we application the item ‘Study on New Composite Material V-Belt For Continuously Variable Transmission Equipped on autos’ from chongqing technological committee (NO6634), in order to give one or more new composite V-belt made from cheaper material, with easy technology in order to improve the develop of the metal V-belt CVT.For the steel wire have good flexility which is standard component cheaper than metal ring, so we use the steel cable take the place of the metal ring named patch metal <WP=7>V-belt; By analyzing the working forces on blocks, metal wire and axial forces on pulleys of the metal pushing V-belt during torque transmitting, formulas for calculating the working forces and the axial forces on pulleys are deduced considering the structure feature of the V-belt, and from the result above find the facture confine the power capacity, and then analyzed the component with EFA, preparing for the optimized design and experiment.After long experiment, we find many shortcoming of this king of V-belt, such as:(1) One V-belt is compose 200~300 metal blocks, each metal block have five work face, tot more than 1500, hard to retain precision, degree of roughness .(2) Big weight, use too much steel.In order to solve these problems we should find a new way. We give a new structure named pillar-wire V-belt. By analyzing the working forces on pillar, metal wire and axial forces on pulleys of the pulling force of V-belt during torque transmitting, formulas for calculating the working forces and the axial forces on pulleys are deduced considering the structure feature of the V-belt, and from the result above find the facture confine the power capacity, and then analyzed the component with EFA, preparing for the optimized design and experiment. We find pillar-wire V-belt is a kind of feasible method, have high meaning on homemade CVT.更多还原