本科畢業(yè)論文，低速工程車輛，1. 變速范圍Ω要求在12～14之間。
2.各檔車輛各檔輸出速度要求如下：單位：(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.變速桿的操縱力不大于100 N。


低速工程車輛變速箱的設(shè)計

摘 要

本設(shè)計是為低速工程車輛進(jìn)行變速箱的設(shè)計，因低速工程車輛工作環(huán)境復(fù)雜，承受載荷變動較大，因此對于變速箱的整體性能要求較高。對于各種零部件材料的選擇偏重于性能較高的材料，以滿足工作要求。變速箱設(shè)計為8個前進(jìn)檔，兩個倒檔，基本結(jié)構(gòu)形式為機械滑動齒輪換檔，組成式變速箱方案，因檔數(shù)設(shè)計較多，為了減小工作尺寸和減少齒輪個數(shù)，采用行星傳動機構(gòu)作為變速箱的副變速裝置，操縱系統(tǒng)采用機械杠桿操縱，即所謂的手動檔變速。本設(shè)計過程中，在對各種變速箱的優(yōu)缺點進(jìn)行分析后，選定為齒輪滑移換檔，組成式變速箱。首先對各檔的齒數(shù)分配通過計算來確定。齒輪的各種參數(shù)接著按步驟來確定，例如齒數(shù)、模數(shù)及分度圓直徑。同時，齒輪的裝配嚙合需要進(jìn)行齒輪變位達(dá)到傳動的平穩(wěn)性及防止齒輪根切。軸上零件的裝配和安裝及軸的強度校核進(jìn)行了復(fù)雜計算。軸承的壽命計算保證車輛的工作壽命要求。行星齒輪結(jié)構(gòu)中的太陽輪、行星輪及齒圈的模數(shù)和齒數(shù)進(jìn)行選擇計算，使設(shè)計出的變速箱滿足了工程車輛的工作要求。

關(guān) 鍵 詞：低速工程，變速箱，行星齒輪系，副變速，組成式

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 錄

前 言 - 1 -
第1章 機械式變速箱的概述及其方案的確定 - 3 -
§1.1 變速箱的功用和要求 - 3 -
§1.2 變速箱結(jié)構(gòu)方案的確定 - 3 -
§1.2.1變速箱傳動機構(gòu)的結(jié)構(gòu)分析與型式選擇 - 3 -
§1.2.2倒檔傳動方案 - 8 -
§1.3變速箱主要零件結(jié)構(gòu)的方案分析 - 8 -
§1.3.1齒輪型式 - 8 -
§1.3.2換檔結(jié)構(gòu)型式 - 9 -
第2章 變速箱主要參數(shù)的確定 - 11 -
§2.1已知條件及設(shè)計指標(biāo) - 11 -
§2.2根據(jù)要求確定車輛傳動系統(tǒng)的總傳動比  - 11 -
第3章 各零部件結(jié)構(gòu)參數(shù)的設(shè)計與計算及強度校核 - 15 -
§3.1直齒圓柱齒輪的設(shè)計 - 15 -
§3.1.1各檔齒輪結(jié)構(gòu)參數(shù)設(shè)計及強度校核 - 15 -
§3.1.2倒檔惰輪的參數(shù)設(shè)計 - 20 -
§3.1.3行星齒輪的參數(shù)設(shè)計 - 21 -
§3.2輸出軸的結(jié)構(gòu)設(shè)計及校核 - 22 -
§3.3 軸承的壽命校核 - 26 -
結(jié) 論 - 30 -
參考文獻(xiàn) - 31 -
致 謝 - 32 -