低速工程车辆变速器设计说明书.doc

本科毕业论文，低速工程车辆，1. 变速范围Ω要求在12～14之间。
2.各档车辆各档输出速度要求如下：单位：(km\h) V1=2～2.5; V2=3～3.5; V3=5～5.5; V4=6.5～7.5; V5=8～8.5; V6=12～12.8; V7=20～21; V8=27～28; VR1=2～2.5; VR1=10～12。
3.变速杆的操纵力不大于100 N。


低速工程车辆变速箱的设计

摘 要

本设计是为低速工程车辆进行变速箱的设计，因低速工程车辆工作环境复杂，承受载荷变动较大，因此对于变速箱的整体性能要求较高。对于各种零部件材料的选择偏重于性能较高的材料，以满足工作要求。变速箱设计为8个前进档，两个倒档，基本结构形式为机械滑动齿轮换档，组成式变速箱方案，因档数设计较多，为了减小工作尺寸和减少齿轮个数，采用行星传动机构作为变速箱的副变速装置，操纵系统采用机械杠杆操纵，即所谓的手动档变速。本设计过程中，在对各种变速箱的优缺点进行分析后，选定为齿轮滑移换档，组成式变速箱。首先对各档的齿数分配通过计算来确定。齿轮的各种参数接着按步骤来确定，例如齿数、模数及分度圆直径。同时，齿轮的装配啮合需要进行齿轮变位达到传动的平稳性及防止齿轮根切。轴上零件的装配和安装及轴的强度校核进行了复杂计算。轴承的寿命计算保证车辆的工作寿命要求。行星齿轮结构中的太阳轮、行星轮及齿圈的模数和齿数进行选择计算，使设计出的变速箱满足了工程车辆的工作要求。

关 键 词：低速工程，变速箱，行星齿轮系，副变速，组成式

THE DESIGN OF LOW SPEED ENGINEERING
VEHICLE TRANSMISSION

ABSTRACT

This design is for the low speed engineering vehicle transmission, because of their complicated working environment. Their bearing capacity always is changing .The request for the transmission’s performance is higher. The choice of all the parts’ material prefer to better quality in order to satisfy the work .The transmission is designed as 8 forwards gear and 2 reverse gear. The basic style of the structure is sliding gear exchange gear, composing transmission project. As there are many gears need to be designed , in order to limit the size and the number of the gears ,the transmission’s auxiliary gear change mechanism adopts the planet driving. The manipulate system adopts mechanism lever operating as it calls the Manual Transmission. The transmission is selected as gear shifting to change transmission and the style of combination after the analyzing to the advantages and drawback of every kind of transmission during the process of design . First of all ,the gear ratio was determined by complex calculating. And then the parameter of each gear was chosen by order as the number of teeth. Modulus .the diameter of diagraph .The gears coupling need to be varied to satisfy the stability of transmission also to avoid undercutting. The part on the shaft’s integrating and layout also the intensive of checking need to calculate. The life of bear calculating to ensure the requests of the vehicles. The planetary gear sets were selected as sun gear planetary gear and the ring’s parameter in order to satisfy the working request of the low speed engineering vehicle.
 
KEY WORDS: Low speed engineering, Transmission, Planetary transmission, Auxiliary speed changing, The style of constitution

目 录

前 言 - 1 -
第1章 机械式变速箱的概述及其方案的确定 - 3 -
§1.1 变速箱的功用和要求 - 3 -
§1.2 变速箱结构方案的确定 - 3 -
§1.2.1变速箱传动机构的结构分析与型式选择 - 3 -
§1.2.2倒档传动方案 - 8 -
§1.3变速箱主要零件结构的方案分析 - 8 -
§1.3.1齿轮型式 - 8 -
§1.3.2换档结构型式 - 9 -
第2章 变速箱主要参数的确定 - 11 -
§2.1已知条件及设计指标 - 11 -
§2.2根据要求确定车辆传动系统的总传动比  - 11 -
第3章 各零部件结构参数的设计与计算及强度校核 - 15 -
§3.1直齿圆柱齿轮的设计 - 15 -
§3.1.1各档齿轮结构参数设计及强度校核 - 15 -
§3.1.2倒档惰轮的参数设计 - 20 -
§3.1.3行星齿轮的参数设计 - 21 -
§3.2输出轴的结构设计及校核 - 22 -
§3.3 轴承的寿命校核 - 26 -
结 论 - 30 -
参考文献 - 31 -
致 谢 - 32 -