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1、附 录附录A 变速器介绍发动机的输出转速非常高,最大功率及最大扭矩在一定的转速区出现。为了发挥发动机的最佳性能,就必须有一套变速装置,来协调发动机的转速和车轮的实际行驶速度。变速器可以在汽车行驶过程中,在发动机和车轮之间产生不同的变速比,通过换挡可以使发动机工作在其最佳的动力性能状态下。变速器的发展趋势是越来越复杂,自动化程度也越来越高,自动变速器将是未来的主流。汽车变速器的任务是传递动力,并在动力的传递过程中改变传动比,以调节或变换发动机的特性,同时通过变速来适应不同的驾驶要求。由此可见,变速器在汽车传动系中扮演着至关重要的角色。随着科技的高速发展,人们对汽车性能的要求越来越高,汽车的性能、
2、使用寿命、能源消耗、振动噪声等在很大程度上取决于变速器的性能,因此必须重视对变速器的研究。变速器的型式: 汽车自动变速器常见的有三种型式:分别是液力自动变速器(AT)、机械无级自动变速器(CVT)、电控机械自动变速器(AMT)。目前应用最广泛的是AT,AT几乎成为自动变速器的代名词。 AT是由液力变扭器、行星齿轮和液压操纵系统组成,通过液力传递和齿轮组合的方式来实现变速变矩。其中液力变扭器是最重要的部件,它由泵轮、涡轮和导轮等构件组成,兼有传递扭矩和离合的作用。 与AT相比,CVT省去了复杂而又笨重的齿轮组合变速传动,而是两组带轮进行变速传动。通过改变驱动轮与从动轮传动带的接触半径进行变速。由
3、于取消了齿轮传动,因此其传动比可以随意变化,变速更加平顺,没有换挡的突跳感。 AMT和液力自动变速器(AT)一样是有级自动变速器。它在普通手动变速器的基础上,通过加装微电脑控制的电动装置,取代原来由人工操作完成的离合器的分离、接合及变速器的选挡、换挡动作,实现自动换挡。手动变速器主要采用齿轮传动的降速原理。变速器内有多组传动比不同的齿轮副,而汽车行驶时的换挡工作,也就是通过操纵机构使变速器内的不同的齿轮副工作。手动变速器又称手动齿轮式变速器,含有可以在轴向滑动的齿轮,通过不同齿轮的啮合达到变速变矩的目的。手动变速器的换挡操作可以完全遵从驾驶者的意志,且结构简单、故障率相对较低、价廉物美。自动变
4、速器是根据车速和负荷(油门踏板的行程)来进行双参数控制,挡位根据上面的两个参数来自动升降。自动变速器与手动变速器的共同点,就是二者都属于有级式变速器,只不过自动变速器可以根据车速的快慢来自动实现换挡,可以消除手动变速器“顿挫”的换挡感觉。自动变速器是由液力变矩器、行星齿轮和液压操纵机构组成,通过液力传递和齿轮组合的方式来达到变速变矩的目的。无级变速器又称为连续变速式无级变速器。这种变速器与一般齿轮式自动变速器的最大区别,是它省去了复杂而又笨重的齿轮组合变速传动,而只用了两组带轮进行变速传动。无级变速器结构比传统变速器简单,体积更小,它既没有手动变速器的众多齿轮副,也没有自动变速器复杂的行星齿轮
5、组,主要靠主动轮、从动轮和传动带来实现速比的无级变化。汽车上广泛采用内燃机作为动力源,其转矩和转速的变化范围很小,而复杂的使用条件要求汽车的驱动力和车速能在相当大的范围内变化。为解决这一矛盾,在传动系统中设置了变速器,用来改变传动比,扩大驱动轮转矩和转速的变化范围,以适应经常变化的行驶条件,如起步、加速、上坡等,同时使发动机在最有利的工况范围下工作;在发动机旋转方向不变的前提下,使汽车能倒退行驶;利用空挡,中断动力传递,以使发动机能够起动、怠速,并便于变速器换挡或进行动力输出。变速器设计的目的就是为了满足上述的要求,使汽车在特定的工况下稳定的工作。变速器除了要能满足一定的使用要求外,还要保证使
6、其和汽车能有很好的匹配性,可以提高汽车的动力性和经济性,保证发动机在有利的工况范围内工作提高汽车的使用寿命、降低能源消耗、减少汽车的使用噪声等。当今世界各大汽车公司对无级变速器的研究都十分活跃。不久的将来,随着电子控制技术的进一步完善,电子控制式的无级变速器可望得到广泛的发展和应用。附录B Transmission descriptionTransmission gearboxs function the engines output rotational speed is high, the maximum work rate and the maximum torque appears i
7、n certain rotational speed area. In order to display engines optimum performance, must have a set of variable speed gear, is coordinated the engine the rotational speed and wheels actual moving velocity. The transmission gearbox may in the automobile travel process, has the different gear ratio betw
8、een the engine and the wheel, through shifts gears may cause the engine work under its best power performance condition. Transmission gearboxs trend of development is more and more complex, the automaticity is also getting higher and higher, the automatic transmission will be future mainstream.Autom
9、otive Transmissions mission is to transfer power, and in the process of dynamic change in the transmission gear ratio in order to adjust or change the characteristics of the engine, at the same time through the transmission to adapt to different driving requirements. This shows that the transmission
10、 lines in the automotive transmission plays a crucial role. With the rapid development of science and technology, peoples car is getting higher and higher performance requirements, vehicle performance, life, energy consumption, such as vibration and noise transmission depends largely on the performa
11、nce, it is necessary to attach importance to the study of transmission.Transmission gearboxs pattern the automobile automatic transmission common to have three patterns: Respectively is hydraulic automatic transmission gearbox (AT), machinery stepless automatic transmission (CVT), electrically contr
12、olled machinery automatic transmission (AMT). At present what applies is most widespread is, AT becomes automatic transmissions pronoun nearly. AT is by the fluid strength torque converter, the planet gear and the hydraulic control system is composed, combines the way through the fluid strength tran
13、smission and the gear to realize the speed change bending moment. And the fluid strength torque converter is the most important part, it by components and so on pump pulley, turbine wheel and guide pulley is composed, has at the same time the transmission torque and the meeting and parting function.
14、 And AT compare, CVT has omitted complex and the unwieldy gear combination variable transmission, but is two groups of band pulleys carries on the variable transmission. Through changes the driving gear and the driven wheel transmission belts contact radius carries on the speed change. Because has c
15、ancelled the gear drive, therefore its velocity ratio may change at will, the speed change is smoother, has not shifted gears kicks the feeling. AMT and the hydraulic automatic transmission gearbox (AT) is the having steps automatic transmission equally. It in the ordinary manual transmission gearbo
16、xs foundation, through installs the electrically operated installment which the microcomputer controls, the substitution originally couplings separation which, the joint and the transmission gearbox completes by the manual control elects to keep off, to shift gears the movement, realizes fluid drive. Manual transmission gear mainly uses the principle of deceleration. Transmission within the group have different tr