1、 I 摘 要 变速器用来改变发动机传到驱动轮上的转矩和转速，目的是在原地起步、爬 坡、转弯、加速等各种行驶工况下，使汽车获得不同的牵引力和速度，同时使发 动机在最有利的工况范围内工作。所以变速器的结构设计的合理性直接影响到汽 车动力性和经济性。设计要求达到换挡迅速、省力、方便、有较高的工作效率、 工作噪声低。因此变速器在汽车中得到广泛应用。 本次设计的是五个前进档加一个倒档的中型专用车的变速器。为了使该变速 器应用范围更加的广泛，应用到不同工程上，使得本变速器带有取力器。变速器 采用中间轴式,换档形式采用的是同步器和滑移齿轮换档，使的换档方便，可靠。 操纵机构设有自锁和互锁装置。 先利用已知参
2、数确定各挡传动比，再后确定齿轮的模数、压力角、齿宽等参 数。由中心矩确定箱体的长度、高度和中间轴及二轴的轴径，然后对中间轴和各 挡齿轮进行校核。在设计过程中，利用 CAXA 绘图，运用 MATALAB 软件编程。最后 绘制装配图及零件图。 通过本次设计，使所设计的变速器工作可靠，传动效率更高。 关键词：变速器，同步器，齿轮，取力器 II Abstract To change the engine used to spread transmission of torque and wheel speed, the aim of starting in place, climb, turn and
3、 accelerate a variety of driving conditions, different vehicle traction and speed, while the engine in the most favorable range conditions.Therefore, the reasonability of the structure design of a transmission gearbox directly affects the vehicles dynamic performance. It is usually required shifting
4、 gears rapidly and conveniently, saving force, and having a higher working efficiency and low working noises. The design of the five forward file plus a reverse of the transmission medium-sized special vehicle. In order to make the transmission more broad range of applications, application to a diff
5、erent project, make a check of the power transmission device. Transmission use of the middle axis, shifting the form of using the synchronizer gear shift and sliding to make the shift easy and reliable. Manipulation of institutions with self-locking and interlocking devices. Using the given basic pa
6、rameters, it was firstly determined the transmission ratio of each shift, the shaft center distances, the gear modulus, the gear pressing angles and widths, and so on. And then the general dimension of the gearbox, including its length, width and height , and then on the intermediate shaft and the block to check gear. During the design process, using CAXA mapping, the use of software programming MATALAB. The final assembly drawing and components drawing Fig. Through this design, so that the des
