1、本科毕业设计（论文） I 摘 要 本次毕业设计的任务是设计一台用于中型货车上的六档机械式变速器。变速器是汽车传动系统中比较关键的一个部件， 合理的设计和布置变速器能使发动机功率得到最合理的利用，从而提高汽车动力性和经济性。 本次毕业设计的设计过程主要包括两大部分：设计部分和利用 Unigraphics软件进行虚拟建模与装配部分。设计过程中首先根据所给参数确定六档机械式变速器布置方案。其次，确定变速器各档的传动比，变速器各零部件的参数。接着进行 齿轮的强度计算、强度校核，轴的设计及强度校核 。然后，采用 UG 软件对变速器进行三维实体建 模、虚拟装配，再导出为二维工程图原型。最后使用 CAD 对
2、变速器的主要零部件及装配图进行工程图的制作。 关键词： 机械式变速器；三维建模；虚拟装配； Unigraphics；强度校核 本科毕业设计（论文） II ABSTRACT This graduation design is mainly about the design of six-shift mechanical transmission using in the medium truck. Transmission is a key component in the drive line of an automobile, so rational design and layout of
3、 the transmission can increase engines power performance and fuel economy. This paper, which mainly consists of two parts： the part of design and the three dimensional model and virtual assembly in UG. First， according to the data given, determine the layout scheme of the six-speed mechanical transm
4、ission. Then the transmission ratio of each shift of the transmission, the gear parameter and so on can be made sure. Next, count and analyze the strength of gears, analyze and verify the strength of each shaft. Then, the three-dimensional solid models of the transmissions parts were established and virtual assembly based on UG software. At last, CAD was used to draw the two dimensional pictures of transmissions each part and the general assembly. Keywords： Manual transmission； Three dimensional model； Virtual assembly；Unigraphics； Intension verified
