自动变速器的基本组成及功能

摘要

车用自动变速器已经经历了半个多世纪的发展，而且其形式也多种多样。在现在轿车上，常见的是采用电控的液力自动变速器，主要是由自动离合器和自动变速器两大部分组成。它能够根据油门的开度和车速的变化，自动的进行换挡。与无级变速器相比，液力自动变速器最大的不同是在结构上，它是由液压控制的齿轮变速系统机构。因此，液力自动变速器并不是真正的无级变速，还是有档位的。其所能实现的是两档之间的无级变速。而无极变速器则是两组变速轮盘和一条传动带组成的，因此，其比传统自动变速器结构简单，体积更小。另外，它可以自由改变传动比，从而实现全程无级变速，使汽车的车速变化平稳，没有传统变速器换挡时那种“顿”的感觉。

无极变速器的无级变速器原理的关键，是两个传动滑轮和联接此二个滑轮的传动带，每个滑轮都由一对彼此合成V形槽的锥体组成，通过传动带联接两滑轮的传动带，利用液压操纵机构移动锥体的开合，使传动带离滑轮轴心的径向位置发生，从而获得二滑轮之间的传动比（一般最大范围可达5：1）。自动变速器多档化虽能扩大自动变速的范围，但它并非安全迅速，只在有级变速与无级变速之间，理想的无级变速器是在整个传动范围内能连续的、无档比的切换变速比，式变速器始终按最佳换挡规律自动变速。无级化是对自动变速器的理想追求。

现在无极变速器传动效率提高，油门反应快、油耗低，随着汽车技术的进步已经越来越不满足于液力自动变速器，希望彻底改进无级变速器，从实现汽车从有级变速阶段的飞跃。福特、菲亚特、奥迪等企业纷纷推出了能够匹配大排量发动机的无级变速器。目前国内的自动挡基本上全是液力自动变速器，只有奥迪采用了无级变速器。奥迪无级/手动一体式变速器，其就在原有的无级变速器基础上，进行多项技术上的创新、改进和提高。

无级变速器装有自动控制装置，行车中可根据车速自动调整换挡，无需人工操作，省去许多换挡及塔踩离合器的工作。

经过对自动变速器的学习，让我进一步了解了它的工作原理，更进一步的了解了自动换挡的原理。

关键词：自动变速器，无级变速器，自动换挡

ABSTRACT

Automatic transmission car has had half a century of development，and its forms and manifold. in the car，and often use of force the automatic transmission，mainly from the clutch and the automatic transmission two parts. it can be based on the gas off and the speed of change，the automatic to change gear. and the level of the transmission，the fluid forces automatic transmission of the biggest difference is in structure it is by hydraulic pressure control of the shift system organizations. therefore，Fluid forces automatic transmission is not really is a variable speed，there is still archives. one can achieve the two documents between the level of the shift. without a transmission is the two groups here and a variable speed drive，therefore，it is better than traditional automatic transmission simple structure，size smaller. in addition，it is free to change ，no change，the level to change the car smoothly，there is no change in the traditional transmission"Meal". a transmission of a transmission of the principle of the key and two pulleys and connected to the transmission of the two pulley quadruples the amount of belts and pulleys are each to each other by a synthesis of v. slots ，through a belt joins two pulleys and belts make use of the hydraulic control moving open to the Pulley radial location，for two blocks of the most widespread generally up to . automatic transmission is how possibly can to expand the scope of the automatic shift，but it is not safe，but in the level of the shift and the level of the shift between the ideal of a transmission is in the whole area has been driven to the document than switches shift in gear is always the best way to change the laws automaticallybelt fromShift. no class this is automatic transmission. it is the ideal for a drive gear efficiency，the gas responsive，fuel，as the technologies are not satisfied with the fluid forces automatic transmission，hoping to complete the improvement of a transmission from the level of implementation of the car from a shift from a stage. ford，filhatre，simply and businesses have launched can big enough to match the engine has no light transmission. the current domestic automatic transmission is the main force automatic transmission，and audi have no light transmission. there is simply a manual transmission ，at the level of transmission and a number of technical innovation and improvement and be equipped with automatic transmission. there is no level control，moving in a Adjusted automatically according to the speed of change，and there is