中型货车变速器设计（三轴式）
摘要
三轴式变速器由于具有体积小、原理简单、工作可靠、操纵方便等优点，故在大多数汽车中广泛应用。本次设计的目的主要是基于对机械原理、机械设计、AutoCAD等知识的熟练运用和掌握，同时运用汽车构造、汽车设计、材料力学、互换性测量等学科知识，对三轴式变速器的各部件进行设计。
首先，本文将概述汽车变速器的现状和发展趋势，介绍变速器领域的最新发展状况。
其次，本文将对不同的变速器传动方案进行比较，选择合理的结构方案进行设计。
再次，本文重点对变速器的两种重要部件—轴和齿轮进行受力分析,强度、刚度的校核计算，以及为这些元件选择合适的工程材料及热处理方法。
最后，本文将对变速器换档过程中的重要部件—同步器以及操纵机构进行阐述，讲述同步器的类型、工作原理、设计方法以及重要参数。
在附录中，本文还将给出进行计算的必要公式、表格及图形，供参考之用。关键词：变速器，同步器，轴，齿轮
Design Three-shaft Transmission for
Medium-duty Truck
Author: Li Bijun
Tutor:Lei Zhengbao
Abstract
Three-shaft transmission is widely used most vehicle for its particular advantages ,such as small dimension ,simply theory ,good stability, conveniently operation .The purpose of my paper is based on the skillful of using mechanic theory ,mechanic design, AutoCAD. Meanwhile, my paper is incorporated structure of vehicle, design of vehicle, mechanic of materials, and survey of interchangeability. I will design the parts of three-shaft transmission.
At first, I will give a summary of the current situation and the tendency of development of the vehicle transmission, and introduce the latest development state in the field of the transmission.
The second, I will compare the transmitting scheme of different transmission, and choose a better structure scheme.
Next, I will do some mechanic analyses, strength, stiffness check of the shafts and gears, which are the important parts of the transmission, and choose appropriate materials and heat treatment.
At last, I will introduce the operation mechanism and the synchronizer, which plays an important role in changing gear. I will give an account of the type, operation, design procedure and major parameter of the synchronizer.
At the supplement, I will write some thing like formula, tableau graph and so on. It may be helpful for the future design.
Key words: Transmission, Synchronizer, Shaft, Gear
目录
1 绪论 (1)
1.1变速器的设计意义及背景 (1)
1.2变速器的现状及发展趋势 (2)
1.3变速器的设计方法和研究内容 (5)
2 变速器结构方案的设计 (6)
2.1两轴式和三轴式变速器 (6)
2.2齿轮安排 (7)
2.3换档结构方式 (8)
2.4倒档的结构方案及倒档轴的位置 (8)
3 变速器轴的设计 (10)
3.1轴的设计 (10)
3.2轴的受力分析与校核计算 (13)
4 变速器齿轮的设计 (21)
4.1齿轮传动的失效形式 (21)
4.2 变速器齿轮设计步骤 (22)
4.3各档齿轮齿数的分配 (26)
4.4 齿轮的材料及其选择原则 (31)
4.5圆柱齿轮强度的简化计算方法 (33)
5 同步器设计 (39)
5.1惯性式同步器 (39)
5.2同步器工作原理 (42)
5.3同步器的主要参数的确定 (42)
6 变速器操纵机构 (46)
6.1操纵机构的功用 (46)
6.2 换档位置图 (46)
6.3变速杆的布置 (46)
6.4锁止装置 (47)
结论 (51)
致谢 (52)
参考文献 (53)
附录 (54)
