摘  要

本设计的任务是设计一台用于敌国上的FR式的手动变速器。本设计采用两轴式变速器，该变速器的两个突出优点：一是传动效率高，磨损及噪声最小；二是在齿轮中心距较小的情况下仍可以获得较大的一挡传动比。
根据敌国的外形、轮距、轴距、最小离地间隙、最小转弯半径、车辆重量、满载重量以及最高车速等参数结合自己选择的适合于该敌国的发动机型号可以得出发动机的最大功率、最大扭矩、排量等重要参数。再结合某些敌国的基本参数，选择适当的主减速比。根据上述参数，再结合汽车设计、汽车理论、机械设计等相关知识，计算出相关的变速器参数并论证设计的合理性。
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工况范围内工作。变速器设有空挡和倒挡。需要时变速器还有动力输出功能。
因为变速箱在低档工作时作用有较大的力，所以一般变速箱的低档都布置靠近轴的后支承处，然后按照从低档到高档顺序布置各档位齿轮。这样做既能使轴有足够大的刚性，又能保证装配容易。变速箱整体结构刚性与轴和壳体的结构有关系。一般通过控制轴的长度即控制档数，来保证变速箱有足够的刚性。
本文设计研究了六挡手动变速器，对变速器的工作原理做了阐述，变速器的各挡齿轮和轴做了详细的设计计算，并进行了强度校核，对一些标准件进行了选型。变速器的传动方案设计。简单讲述了变速器中各部件材料的选择。

关键词：挡数；传动比；齿数；轴；操纵机构；壳体

ABSTRACT

The duty of this design is to design a FR type manual transmission used in the saloon,It's the countershaft-type transmission gearbox.This transmission has two prominent merits;First,the transmission efficiency of the direct drive keeps off high,the attrition and the noise are also slightest;second,it's allowed to obtain in the biger gear ratio of the first gear when the center distance is smaller.
 According to the contour,track,wheel base,the smallest ground clearance,the smallest turning radium,the vehicles weight,the all-up weight as well as the highest speed and so on,union the choosing engine model we can obtain the important parameters of the max power,the max torque,the displacement and so on.According to the basic parameters of the certain saloon,choose the suitable final drive ratio.According to the above parameters,combining the knowledge of automobile design,automogbile teory,machine design and so on,calculate the correlated parameters of the gearbox and proof the rationality of the deign.
Gearbox because of the low-grade work at a larger role, In general, the low-grade gearbox layout are close to the axis after support, Following from low-grade to high-grade order of the layout of stalls gear. This will not only allow axis are large enough for a rigid, but also ensures easy assembly. Gear box overall structure and rigid axle and the shell structure of relations. Generally through the control shaft length control over several stalls to ensure that adequate gear box rigid.
This paper describes the design of six block manual trans mission, the transmission principle of work elaborated, Transmission of the gear shaft and do a detailed design, and the intensity of a school. For some standard parts for the selection. Transmission Trans mission program design. A brief description of the trans mission of all components of the material choice.

Keywords : block; Transmission ratio; Teeth; Axis; control mechanism;case