毕业设计
题 目 三轴五档手动变速器设计
专 业 机械设计制造动化
学 号
学 生
指导教师
答辩日期 2014
摘
设计务设计台轿车五档手动变速器合理设计布置变速器发动机功率合理利提高汽车动力性济性变速传动机构作改变转距转速数值方操机构作控制传动机构实现变速器传动改变实现换挡达变速变距
文参阅国外量文献首先简单叙述机械式变速器发展历史变速器位作讨现状未发展趋势进研究机械式变速器基结构变速原理中重点研究传动机构（轴齿轮）基结构特点工作原理机械式变速器挡传动路线进行简分析文章包括量计算程具体容：变速器布置方案分析变速器回转件结构参数确定步器结构工作原理挡齿轮强度校核轴强度校核轴承寿命计算等
关键词 齿轮步器变速器
Abstract
This design task is to design a car for five manual shift transmission Reasonable design and decorate transmission can make the engine power to get the most reasonable use of so as to improve the dynamic performance and fuel economy cars Variable speed transmission＇s main function is to change the torque and speed of numerical and direction Operation is the main purpose of control transmission mechanism realize the transmission ratio of the gearbox change which realize the shift in order to achieve the change from the speed
This article refer to the domestic and foreign many papers and first simply describes the mechanical transmission of the history the status and effect of the transmission and discussed its present situation and future development trend And then we study the basic structure of the mechanical transmission and variable speed principle which focus on the transmission mechanism (mainly shaft and gear) the basic structure characteristic and work principle mechanical transmission of each block transmission line are briefly analyzed The articles included a large amount of calculation process and the specific contents the layout of transmission analysis the transmission structure paramete determination of turning a synchronizer the structure and the working principle each block of the gear axis strength check the intensity the service life of the bearings calculations etc
Keywords Gear Shaft Synchronizer Three axis five gear
目 录
摘 I
Abstract II
第1章 绪 1
11 设计目意义 1
12 变速器发展 1
13变速器设计求 3
14设计容思路 3
141设计容 3
142设计思路 4
15章结 4
第2章 变速器整体结构方案设计 5
21变速器传动机构型式选择结构分析 5
211变速器传动方案较 5
212倒档布置方案 6
22章结 7
第3章 变速器参数选择齿轮设计 9
31变速器参数选择 9
311档位数传动 9
312中心距 10
313齿轮模数 11
314压力角α螺旋角β齿宽b 12
315齿轮变位系数 13
32档传动齿轮齿数确定 13
321确定档齿轮齿数 13
322确定常啮合齿轮副齿数 14
323确定档位齿数 15
324确定倒档齿轮齿数 15
325确定齿轮轮齿尺寸 15
33章结 16
第4章 变速器齿轮强度计算材料选择 17
41齿轮失效形式 17
42齿轮强度计算材料接触应力 17
421齿轮弯曲强度计算 17
422齿轮材料接触应力 19
43章结 21
第5章 变速器轴设计校核 22
51变速器轴结构尺寸 22
511轴结构 22
512轴尺寸 22
52轴校核 23
521第轴强度刚度校核 23
522第二轴强度刚度校核 24
53章结 26
第6章 变速器步器操机构设计 27
61步器设计 27
611步器工作原理 27
612步环参数确定 28
62变速器操机构 30
621操机构功 30
622操机构设计求 31
623变速器换档位置 32
63章结 32
第7章 轴承选寿命计算 33
71 第轴轴承选计算 33
72第二轴轴承选计算 33
73章结 34
结 41
致 谢 42
参考文献 43
第1章 绪
11 设计目意义
着国汽车工业断壮汽车行业持续快速发展设计出济实惠工作性优良汽车已前汽车设计者紧迫问题发挥发动机佳性必须套传动效率高维修保养成低够带驾驶乐趣变速装置协调发动机转速车轮实际行驶速度
该课题针机械专业学生学生解变速器设计通课题研究学生完成理课程实践总结获定工程设计工作方法更学掌握现代汽车设计机械设计全面知识锻炼学生利学知识分析问题解决问题力
12 变速器发展
汽车变速箱100年历史中历手动动发展程目前世界汽车变速器手动变速器（MT）动变速器（AT）手体变速器（AMT）级变速器（CVT）双离合变速器（DCT）五种型式
（1）手动变速器(MT)
手动变速器（Manual Transmission）采齿轮组档齿轮组齿数固定档变速定值断言繁琐驾驶操作等缺点阻碍汽车高速发展步伐手动变速器会久淘汰事物发展角度说话确实道理目前市场需求适角度手动变速器会早离开首先商车特性说手动变速器功变速器代次老司机部分男士司机说爱手动变速器第三着生活水断提高现轿车已进入家庭普通工薪阶级老百姓说济型轿车合适手动变速器身性价配套济型轿车厂家济适型轿车销量直车市名列前茅
（2）动变速器（AT）
动变速器（AutomaticTransmission）利行星齿轮机构进行变速根油门踏板程度车速变化动进行变速驾驶者需操加速踏板控制车速说动变速汽车没离合器动变速器中离合器离合器车速变化动分离合闭达动变速目
（3）手动动变速器（AMT）
型车档位设+选择档位D档时变换降档()加档(+)手动档样动—手动变速系统提供两种驾驶方式—驾驶乐趣手动档交通拥挤时动档样变速方式国现状非常适合
（4）级变速器（CVT）
汽车产业发展非常迅速户汽车性求越越高汽车变速器发展仅限级变速器便追求高境界级变速系统手动变速器动变速器样齿轮变速两滑轮钢带变速传动意变化没换档突跳感觉克服普通动变速器突然换档油门反应慢油耗高等缺点
（5）双离合变速器（DCT）
DCT结合手动变速器燃油济性动变速器舒适性传统手动变速器演变目前代表变速器高技术双离合变速器(Dual Clutch Transmission) DCT般动变速器系统基手动变速器动变速器拥手动变速器灵活性动变速器舒适性外提供间断动力输出传统手动变速器台离合器换挡时驾驶员须踩离合器踏板挡齿轮做出啮合动作动力换挡期间出现间断令输出表现断续
针中国变速器市场发展趋势Global Insight亚洲区技术分析师段诚武博士阐述点见解：
（1）短期手动档变速器然占份额动档变速器更增长空间
（2）鉴中国市场情况复杂性长期变速器单式发展趋势没种形式变速器会成赢家
（3）中国市场技术支持目前市场份额设备提供方面AMTLPGAUTOE汽油CVTE混合动力DCT柴油具相似性
（4）长远中国土企业应该更加关注DCT产品非常前景
13变速器设计求
（1）应保证汽车具高动力性济性指标汽车整体设计时根汽车载重量发动机参数汽车求选择合理变速器挡数传动满足求
（2）工作操轻便汽车行驶程中变速器应动跳挡乱挡换挡击等现象发生减轻驾驶员疲劳强度提高行驶安全性操轻便求日益显重通采步器预选气动换挡动半动换挡实现
（3）重量轻体积影响指标参数变速器中心距选优质钢材采合理热处理设计合适齿形提高齿轮精度选圆锥滚柱轴承减中心距
（4）传动效率高减齿轮啮合损失应直接挡提高零件制造精度安装质量采适润滑油提高传动效率
（5）噪声采斜齿轮传动选择合理变位系数提高制造精度安装刚性减齿轮噪声
14设计容思路
141设计容
1齿轮参数选择设计校核计算
2齿轮轴设计校核计算
3步器设计计算
4轴承选择设计校核计算
5CATIA软件进行三维建模
142设计思路
查变速器相关资料理解变速器结构组成工作原理先变速器进行整体布置包括整体传动方案倒档布置次次变速器中齿轮轴进行设计计算确定齿轮轴尺寸CAD进行草图绘制基础步器进行设计计算进步完善草图部分进行校核计算查尺寸否满足求果正确进行修改着重分析步器操机构工作原理进行细化处理出张操机构图纸CAD二维图纸绘制完成CATIA软件进行三维建模仿真运动立体结构更直观变速器呈现出部机构配合更清楚
15章结
章变速器发展历史未方进行初步解手动变速器未较乐观巨市场章明确该设计目意义设计会严格目做保证会偏离方变速器设计求需严格遵守直接关系变速器安全性舒适性次设计设计容设计思路进行展开进步明确设计方案
第2章 变速器整体结构方案设计
21变速器传动机构型式选择结构分析
变速器种类传动改变方式分级级综合式级变速器根前进档档数分三四五档档变速器轴中心线位置分固定轴线式螺旋轴线式综合式中固定轴式应广泛两轴式三轴式分前者发动机前置前轮驱动汽车者发动机前置轮驱动汽车
211变速器传动方案较
图23三轴式五档变速器传动方案特点：变速器第轴第二轴轴线直线啮合套连接直接档直接档变速器齿轮轴承中间轴均承载发动机转矩变速器第轴第二轴直接输出时变速器传动效率高达90噪声低齿轮轴承磨损减少直接档利率高档位提高变速器寿命前进档位工作时变速器传递动力需设置第轴中间轴第二轴两齿轮传递变速器中间轴第二轴间距离（中心距）条件档然较传动档位高齿轮采常啮合齿轮传动档位低齿轮（档）采采常啮合齿轮传动数传动方案中档外档位换档机构均采步器啮合套换档少数结构档采步器啮合套换档档步器啮合套数情况装第二轴直接档外档位工作时三轴式变速器传动效率略降低缺点档数相条件种三轴式变速器常啮合齿轮数换档方式倒档传动方案差
图23a示方案倒档直齿滑动齿轮换档外余档常啮合齿轮传动图23bcd示方案前进档均常啮合齿轮传动
图23d示方案中倒档超速档安装位变速器部副箱体样布置提高轴刚度减少齿轮磨损降低工作噪声外需超速档条件形成四前进档变速器
图23
种方案中采常啮合齿轮传动档位换档方式步器啮合套实现变速器中档位步器换档档位啮合套换档定档位高步器换档档位低啮合套换档
变速器图23c示支承结构方案提高轴刚度时轴面分开壳体较解决轴齿轮等零部件装配困难问题图23c示方案高档动齿轮处悬臂状态时档倒档齿轮布置变速器壳体中间跨距里中间档步器布置中间轴方案特点
设计采23b布置方案
212倒档布置方案
常见倒档结构方案种：
图24a常见倒挡布置方案前进档传动路线中加入传动结构简单齿轮处正负交称变化弯曲应力状态工作方案广泛轿车轻型货车四档全步器式变速器中
图24b示方案优点换倒挡时利中间轴挡齿轮缩短中间轴长度换挡时两齿轮时进入啮合换挡困难某轻型货车四档变速器采方案
图24c示方案获较倒挡传动缺点换挡程序合理
图24d示方案针前者缺点做修改常货车变速器中
图24e示方案中间轴倒挡齿轮做成体齿宽加长
图24f示方案适全部齿轮副均常啮合齿轮换挡更轻便
充分利空间缩短变速器轴长度货车倒挡传动采图24g示方案缺点倒挡须根变速器拨叉轴致变速器盖中操机构复杂
图24
综合考虑次设计采图24f示方案倒档换档方式
22章结
章分析较变速器传动机构形式结构着重分析动力布置形式倒档形式分析结构进行明确动力传递路线更合理布置档位选取传动更加简单倒档布置方式面设计计算基础
第3章 变速器参数选择齿轮设计
设计根 Polo 2011款劲取 16 MT实酷版开展设计中采相关参数均源种车型表31示：
表31
减速
316
扭矩
155Nm3750rpm
高时速
188kmh
功率
77kw5000rpm
轮胎型号
18560R15
发动机型号
EA111
整备质量
1155Kg
31变速器参数选择
311档位数传动
降低油耗提高燃油利率变速器档数应该适增加目前车般45档位变速器设计采5档位
选择低档传动时应根汽车爬坡度驱动轮路面附着力汽车低稳定车速减速驱动轮滚动半径等综合考虑确定
汽车爬陡坡时车速高空气阻力忽略驱动力克服轮胎路面间滚动阻力爬坡阻力
（31）
爬坡度求变速器Ⅰ档传动
（32）
式中 m——汽车总质量
g ——重力加速度
ψmax ——道路阻力系数
rr ——驱动轮滚动半径
Temax ——发动机转矩
i0——减速
η ——汽车传动系传动效率
根驱动车轮路面附着条件
求变速器I档传动：
（33）
式中 G2——汽车满载静止水路面时驱动桥路面载荷
φ ——路面附着系数计算时取φ0506
已知条件：满载质量 1530kgrr286mmη095f003
根公式（33）：igI 348
超速档传动：
(34)
已知条件：
中间档传动理公：
（35）
等数列实际理略出入齿数整数常档位间公宜外考虑发动机参数合理匹配根式出：1398
：（修正1）
312中心距
中心距变速器尺寸质量直接影响选中心距应保证齿轮强度三轴式变速器中心距A根已变速器统计出验公式进行初选
（36）
式中K A ——中心距系数轿车取K A 89~93（取92）
TI max ——变速器处档时输出轴输出扭矩：
TI maxTe max igI η 5178N﹒m
出初始中心距A7388mm
313齿轮模数
齿轮模数选取般原：
(1)减少噪声应合理减模数时增加齿宽
(2)质量应该增加模数时减少齿宽
(3)工艺方面考虑挡齿轮应该选种模数
(4)强度方面考虑挡齿轮应模数
轿车减少工作噪声较重模数应选货车减质量减噪声更重模数应选
选模数值应符合国家标准规定
建议列式选取齿轮模数第轴常啮合斜齿轮法模数mn
（37）
中155Nm出mn252
档直齿轮倒档齿轮模数m
mm （38）
通计算m26
表32渐开线齿轮标准模数m （摘GBT13571987）mm
第系列
1 125 15 20 25 3 4 5 6 8 10
第二系列
175 225 275（325）35（375）45 55（65） 7 9
注：优先采第系列括号模数
：
314压力角α螺旋角β齿宽b
压力角较时重合度传动稳噪声低较时提高轮齿抗弯强度表面接触强度轿车加重合度已降低噪声取货车提高齿轮承载力取设计中变速器齿轮压力角α取国家规定标准压力角20°
变速器斜齿轮螺旋角般范围螺旋角增齿轮啮合重合度系数增加工作稳噪声降低外齿轮强度提高螺旋角太会轴力轴承载荷轿车变速器齿轮转速高求噪声螺旋角取较值应该注意选取斜齿轮螺旋角时候应该中间轴轴力衡第二轴轴力轴承盖壳体承受中间轴全部齿轮螺旋方应该律做成右旋第二轴齿轮做成左旋
齿轮宽度b直接影响着齿轮承载力b加齿承载力增高试验表明齿宽增定数值载荷分配均匀反齿轮承载力降低保证齿轮强度条件量选取较齿宽利减轻变速器重量缩短轴尺寸
通常根齿轮模数选定齿宽：
直齿 b(4575)mmm
斜齿 b(6585)mm
第轴常啮合齿轮副齿宽系数值取接触线长度增加接触应力降低提高传动稳性齿轮寿命
已知： m26
：常啮合齿轮齿宽取20mm235档齿轮齿宽取175mm倒档档齿轮齿宽取13mm
（注：保证装配接触宽度b通常取齿轮宽度b齿轮宽度b210mm强度计算时b）
315齿轮变位系数
变位齿轮两类：高度变位角度变位高度变位齿轮副啮合齿轮变位系数零高度变位增加齿轮齿根强度达齿轮强度想接程度高度变位齿轮副缺点时增加齿轮强度难降低噪声角度变位齿轮副变位系数等零角度变位获良啮合性传动质量指标采较
变位系数选择原 ：
(1)高档齿轮应保证接触强度抗胶合耐磨损利原选择变位系数
(2)低档齿轮提高齿轮齿根强度应根危险断面齿厚相等条件选择齿轮变位系数
(3)总变位系数越齿轮齿根抗弯强度越低易吸收击振动噪声
降低噪声变速器中二档外档齿轮总变位系数选较数值般情况着档位降低总变位系数应该逐档增二档倒档齿轮应该选较值
32档传动齿轮齿数确定
321确定档齿轮齿数
已知档动：
（39）
确定Z9Z10齿数先求齿数：
（310）
中 A 7388mmm 3选择齿轮齿数时应注意相配齿轮齿数偶数减少齿轮齿数间公约数机会否会引起齿面均匀磨损取57轿车三轴式变速器时处取18出39
面根初选Am计算出整数调整整数中心距变化时应齿轮变位系数反计算中心距A修正中心距作计算
里修正57根式（310）反推出A75mm
322确定常啮合齿轮副齿数
式（38）求出常啮合齿轮传动
（311）
已知数：
常啮合齿轮中心距档齿轮中心距相等斜齿轮中心距
（312）
：
（313）
根已知数计算出：
联立方程式：2033
计算出档实际传动实际螺旋角
323确定档位齿数
二档传动
（314）
（315）
：
联立方程式：
样方法分计算出：三档齿轮 五档齿轮
324确定倒档齿轮齿数
取Z22
A （316）
Z+Z58分配Z17Z40
倒挡轴中间轴中心距507mm
防止干涉1112齿轮齿顶圆保持05mm间隙
d906mm
325确定齿轮轮齿尺寸
齿顶高：
斜齿轮齿顶高25mm直齿轮齿顶高26mm
齿根高：
斜齿轮齿根高31mm直齿轮齿根高325mm
33章结
章变速器齿轮参数进行设计计算确定齿轮模数齿数压力角斜齿轮螺旋角等齿轮参数确定CATIA参数化建模提供利渐开线画法进行三维制图草图绘制确定分度圆直径
第4章 变速器齿轮强度计算材料选择
41齿轮失效形式
齿轮失效形式：轮齿折断齿面点蚀齿面磨损齿面胶合塑性形变
42齿轮强度计算材料接触应力
机械设备变速器较途汽车变速器齿轮条件相似外汽车变速器齿轮材料热处理方法加工方法精度等级支撑方式基致汽车变速器齿轮低碳合金钢制造采剃齿齿轮精加工齿轮表面采渗碳淬火热处理工艺齿轮精度低7级计算通齿轮强度公式更简化计算公式计算汽车齿轮样获较准确结果里选择齿轮材料40Cr
421齿轮弯曲强度计算
（1）直齿轮弯曲应力
（41）
式中 ——弯曲应力（MPa）
——档齿轮10圆周力（N） 中计算载荷（N·mm）d节圆直径
——应力集中系数似取165
——摩擦力影响系数动齿轮取11动齿轮取09
b ——齿宽（mm）
t ——端面齿距（mm）
y ——齿形系数图41示
图41 齿形系数图
处档时中间轴计算扭矩：
（42）
求 139500N
出出数代入式（41）
计算载荷取作变速器第轴扭矩时档直齿轮弯曲应力400850MPa间
（2）斜齿轮弯曲应力
（43）
式中 重合度影响系数取20参数均式（41）注释相选择齿形系数y时模数图（41）中查
二档齿轮圆周力：
（44）
根斜齿轮参数计算公式出：53701N
齿轮8齿数z22查表（41）：
求：
理：
计算二档齿轮方法出档位齿轮弯曲应力计算结果：
三档：
五档：
计算载荷取作第轴扭矩时常啮合齿轮高档齿轮许应力180350MPa范围
述直齿轮斜齿轮计算结果均符合弯曲强度求
422齿轮材料接触应力
齿轮接触应力
（45）
式中——齿轮接触应力（MPa）
F ——齿面法力（N）
——圆周力（N）
——节点处压力角（°）
——齿轮螺旋角（°）
E ——齿轮材料弹性模量（MPa）查资料取
B ——齿轮接触实际宽度
——动齿轮节点处曲率半径（mm）
直齿轮：
（46）
（47）
斜齿轮：
（48）
（49）
中分动齿轮节圆半径（mm）
作变速器第轴载荷作计算载荷时变速器齿轮许接触应力见表41：
表41
齿轮
MPa
渗碳齿轮
液体碳氮渗齿轮
档倒档
19002000
9501000
常啮合齿轮高档
13001400
650700
通计算出档齿轮接触应力分：
档：1849MPa二档：12064MPa三档：11915MPa
五档：12397MPa
表41知设计变速器齿轮接触应力基符合求
43章结
章分析齿轮失效形式设计齿轮进行强度接触应力计算通计算发现齿轮符合设计求够保证求齿轮校核计算时非常关键步检测前选取计算正确否防止更错误产生
第5章 变速器轴设计校核
51变速器轴结构尺寸
511轴结构
第轴通常齿轮做成体前端支撑飞轮腔轴承轴径根前轴承径确定该轴承承受轴力轴轴定位般轴承卡环轴承盖实现第轴长度离合器轴尺寸确定花键尺寸应离合器动盘毂花键统考虑第轴图51示：
图51 变速器第轴
中间轴分旋转轴式固定轴式设计采旋转轴式传动方案档倒档齿轮较通常中间轴做成体高档齿轮分键固定轴便齿轮磨损更换
512轴尺寸
变速器轴确定尺寸结构布置求考虑加工工艺装配工艺求定草图设计时齿轮换档部件工作位置尺寸初步确定轴长度轴直径参考类汽车变速器轴尺寸选定列验
第轴中间轴： （51）
第二轴： （52）
式中——发动机扭矩N·m
保证设计合理性轴强度刚度应定协调关系轴直径d轴长度L关系式选取：
第轴中间轴：dL016018
第二轴：dL018021
52轴校核
变速器结构布置考虑加工装配确定轴尺寸般说强度足够仅危险断面进行验算设计变速器说设计程中轴强度刚度留定余量进行校核时需校核档处车辆行进程中档传动扭矩轴承受扭矩第二轴结构较复杂作重点校核象面第轴第二轴进行校核
521第轴强度刚度校核
第轴运转程中受弯矩忽略认受扭矩中情况轴扭矩强度条件公式
（53）
式中 ——扭转切应力MPa
T ——轴受扭矩N·mm
——轴抗扭截面系数
P ——轴传递功率kw
d ——计算截面处轴直径mm
[] ——许扭转切应力MPa
中P 77kwn 5000rmind 30mm代入式：
查表知[]55MPa[]符合强度求
轴扭转变形米长扭转角表示计算公式：
（54）
式中 T ——轴受扭矩N·mm
G ——轴材料剪切弹性模量MPa钢材G 81MPa
——轴截面极惯性矩
已知数代入式：
般传动轴取符合刚度求
522第二轴强度刚度校核
（1）轴强度校核
计算齿轮啮合圆周力径力轴力式求出：
（55）
（56）
（57） 式中 ——计算齿轮传动处档传动348
d ——计算齿轮节圆直径1014mm
——节点处压力角20°
——螺旋角30°
——发动机转矩155000N·mm
代入式：
危险截面受力图：
图53 危险截面受力分析
水面：（160+83）83 出15272N
水面受力矩：
垂直面：
（58）
求出 57236N
垂直面受力矩：
该轴受扭矩：
危险截面受合成弯矩：
（59）
M
弯矩转矩联合作轴应力（MPa）：
（510）
代入式：低档工作时[]400MPa： 符合求
（2）轴刚度校核
第二轴垂直面挠度水面挠度分式计算：
（511）
（512）
式中 ——齿轮齿宽中间面径力（N）里等
——齿轮齿宽中间面圆周力（N）里等
E ——弹性模量（MPa）（MPa）
I ——惯性矩（）d轴直径（）
ab ——齿轮坐作力距支座AB距离（）
L ——支座间距离（）
数值代入式（511）（512）：
轴全挠度符合刚度求
53章结
章变速器轴进行设计计算第轴通常齿轮做成体中间轴选旋转式低档位齿轮轴做成体高档齿轮键轴连接传递扭矩第二较复杂面矩形花键选取设计轴进行校核计算满足实际求
第6章 变速器步器操机构设计
61步器设计
前面已说明设计采步器类型锁环式步器结构图61示：
图61 锁环式步器
19变速器齿轮 2滚针轴承 38结合齿圈 47锁环（步环）
5弹簧 6定位销 10花键毂 11结合套
611步器工作原理
图62类步器工作原理：换档时轴作啮合套换档力推啮合套带动定位销锁环移动直锁环锥面接合齿轮锥面接触止作锥面法力两锥面间存角速度差致锥面作摩擦力矩锁环相啮合套滑块转角度滑块予定位接啮合套齿端锁环齿端锁止面接触（图62b）啮合套移动受阻步器锁止状态换档第阶段结束换档力锁环继续压锥面摩擦力矩增时锁止面处作方相反拨环力矩齿轮锁环角速度逐渐角速度相等瞬间步程结束完成换档程第二阶段工作摩擦力矩消失拨环力矩锁环回位两锁止面分开步器解锁止状态接合套接合齿换档力作通锁环齿轮接合齿啮合（图62d）完成步换档
图62 锁环步器工作原理
612步环参数确定
(1)步环锥面螺纹槽
果螺纹槽螺线顶部设计窄刮存摩擦锥面间油膜效果顶部宽度窄会影响接触面压强磨损加快试验证明：螺纹齿顶宽摩擦数影响摩擦数齿顶磨损降低换挡费力齿顶宽易螺纹槽设计刮油存螺纹间间隙中螺距增会接触面减少增加磨损速度图63a中出尺寸适轻中型汽车图63b适重型汽车通常轴泄油槽6～12槽宽3～4mm
图63 步器螺纹槽形式
(2)锥面半锥角
摩擦锥面半锥角越摩擦力矩越摩擦锥面产生锁现象避免锁条件tan般6°～8°6°时摩擦力矩较锥面表面粗糙度控制严时粘着咬住倾时少出现咬住现象
次设计中采锥角均取7°
(3)摩擦锥面均半径R
R设计越摩擦力矩越R受结构限制包括变速器中心距相关零件尺寸布置限制R取会影响步环径厚度尺寸取约束取原条件R取
次设计中采R50～60mm
(4)锥面工作长度b
（61）
设计中考虑降低成取相b取5mm
(5)步环径厚度
摩擦锥面均半径样步环径厚度受机构布置限制包括变速器中心距相关零件特锥面均半径布置限制宜取厚步环径厚度必须保证步环足够强度
轿车步环厚度货车应选锻件精密锻造工艺加工制成提高材料屈服强度疲劳寿命货车步环压铸加工段造时选锰黄铜等材料变速器高强度高耐磨性钢配合摩擦副钢质球墨铸铁步环锥面喷镀层钼（厚约03～05mm）摩擦数钢铜合金摩擦副范围耐磨性强度显著提高步环铜环基体锥空表面喷厚007～012mm钼制成喷钼环寿命铜环2～3倍钢质基体步环仅节约铜提高步环强度
设计中步器径宽度取105mm
(6)锁止角
锁止角选取正确保证换档两部分间角速度差达零值进行换档影响锁止角选取素摩擦数擦锥面均半径R锁止面均半径锥面半锥角已结构锁止角26°～46°范围变化
次设计锁止角取
(7)步时间t
步器工作时连接两部分达步时间越短越步器结构尺寸转动惯量步时间影响外变速器输入轴输出轴角速度差作步器摩擦锥面轴力均步时间影响轴力步时间减少轴力作变速杆手柄力关车型求作手柄力相步时间车型关计算时属范围选取：轿车变速器高档取015～030s低档取050～080s货车变速器高档取030～080s低档取100～150s
62变速器操机构
621操机构功
变速器操机构功保证档齿轮啮合套步器移动规定距离获求档位允许时挂两档位
622操机构设计求
(1)锁止装置包括锁互锁倒档锁
a互锁装置保证移动某变速叉轴时变速杆叉轴互锁止互锁装置结构种：互锁销式摆动锁块式转动锁止式三锁销式次设计中互锁装置选择第种结构型式图64示
b锁装置作定位防止汽车振动轴力作致脱档保证啮合齿轮全齿长进行啮合驾驶员换档感觉定位作通锁装置中弹簧钢球（锁销）推入叉轴凹臼中实现变速叉轴凹臼间距挂档齿轮移动距离决定结构型式图64示
c汽车行驶程中防止误挂倒档致造成安全事损坏传动系操机构中设倒档锁倒档安全装置倒档锁驾驶员挂倒档时驾驶员明显手感起提醒作防止误挂倒档结构见总装配图
图64 变速器锁互锁结构
1锁钢球 2锁弹簧 3变速器盖4互锁钢球 5互锁销 6拨叉轴
(2)换档动作轻便省力减轻驾驶员疲劳强度
(3)应驾驶员必手感
623变速器换档位置
设计操机构首先确定换档位置换档位置确定换档方便考虑应该注意三点：
(1)换档次序排列
(2)常档放中间位置档放两边
(3)避免误挂倒档倒档安排边位置时1档组成排
根三点次设计变速器换档位置图65示：
图65 换档位置图
63章结
章步器基结构工作原理进行分析步器参数进行选取包括螺纹槽数宽度半锥角摩擦锥面均半径等解变速器操机构作设计求必须包括锁互锁倒档锁样保证操作省力容易挂错档位
第7章 轴承选寿命计算
71 第轴轴承选计算
1初选轴承型号
工作条件轴颈直径初选轴轴承型号6306转速5000rmin
2计算轴承量动载荷
（71）
（72）
（73）
查表e038查表X056Y115
量动载荷：
48317N （74）
3计算轴承基额定寿命
轴承基额定寿命：（寿命指数球轴承3）
（75）
带入201873h20000h满足求
72第二轴轴承选计算
1初选轴承型号
工作条件轴颈直径初选二轴轴承型号6305转速5000rmin
2计算轴承量动载荷
（76）
（77）
（78）
查表e044查表X056Y100
量动载荷：
86285N （79）
3计算轴承基额定寿命
轴承基额定寿命：
（710）
带入213408h20000h满足求
73章结
章变速器轴承进行选校核轴承变速器重组成部分保证齿轮轴旋转运动章轴承寿命进行校核变速器转速非常高需根变速器整体布置进行合适轴承选择保证整体寿命
第8章
81 CATIA软件简介
CATIA V5软件法国Dassault公司1975年开发套完整3D CADCAMCAE 体化软件容涵盖产品概念设计工业设计三维建模分析计算动态模拟仿真工程图生成生产加工成产品全程中包括量电缆道布线种模具设计分析机交换等实模块CATIA V5 保证企业部设计部门间协设计功提供企业整集团设计流程端端解决方案CATIA V5 量应航空航天汽车摩托车行业机械电子家电3C产业NC加工等领域
功强完美CATIA V5 已成三维CADCAM领域面旗帜争相遵准特航空航天汽车摩托车领域CATIA V5 仅户提供详细解决方案具先进开发性集成性灵活性功：三维图形设计二维工程蓝图绘制复杂空间曲面设计验证三维计算机辅助加工制造加工轨迹模拟机构设计运动分析标准零件理
82变速器软件设计
821齿轮建模
（1）选择文件à新建命令类型列表中选择Partà确定à启混合设计à确定
（2）进入创成式外形设计àf(x)进入公示编辑界面图81
图81
然齿轮进行参数化设计编辑公示图82
图82
（3）选择XY面à草绘à创建4圆编辑公示半径分d2da2db2df2图83
图83
（4）单击规à新建规Xà编辑公式
XXdb2*cos(PI2*t)+db2*PI2*t*sin(PI2*t)à
重复述步骤编辑公式
Ydb2*sin(PI2*t)db2*PI2*t*cos(PI2*t)à创建点图84
图84 图85 图86
à样条曲线链接点à提取分度圆à相交à面参考相交点Z轴à面角度法线（角度360deg(4*z)）à提取分度圆à外插延伸à称图85
（5）提取齿顶圆à进入XY面à投影齿顶圆齿根圆样条曲线à倒角pfà投影面图86à旋转（角度asin(2*b*tan(beta)d)）à截面曲面à厚曲面à阵列图87
图87
822变速器装配
先选择输入轴作固定件然相合约束偏移约束接触约束等命令齿轮步器等零部件进行装配约束装配完 成状态图88
图88
823变速器仿真
（1）新建机构1à创建齿轮接头图89à创建刚性固连零件连起图810
（2）创建机构2à创建柱块接头图811à步骤创建2档位接头图812
图89
图811
图810 图812
83章结：
通变速器三维软件建模更深刻学结构组装时该软件更加熟练特模块中装配仿真工作基础
结
次设计汽车变速器部分变速器车辆缺部分中机械式变速箱设计发展天技术已成熟踏出校门学生说中设计理念值探讨学
次设计变速箱说特点：扭矩变化范围满足工况求结构简单易生产维修价格低廉采步器挂挡变速器挂挡稳噪声降低轮齿易损坏设计中采五档手动变速器通较变速器传动变化范围满足汽车工况求达济性动力性求变速器挂档时结合套然增加成汽车变速器操舒适度增加齿轮传动更稳着实性济性原部件设计求采较开放标准安全系数高点次设计理想处工作学中会继续学研究变速器技术求设计更加合理济
紧张忙碌毕业设计已接尾声次设计学学次综合检验更次综合学程毕业设计仅学巩固专业课知识解少相关专业知识力提高时锻炼协作精神踏入社会工作良基础
致 谢
转眼间学四年快结束作学生活环节—毕业设计12周紧张准备接尾声次毕业设计中巩固前学知识中学新东西尤汽车设计汽车理两门课程里四年里巨帮助老师学表示衷心感谢正帮忙圆满完成四年学业毕业设计
次设计程中指导老师XX直关注着步进展意见建议时提出严格求利完成毕业设计务李老师指导分开表示感谢
外遇技术困难时候车辆工程专业老师帮助需帮助时候非常耐心解答里表示衷心感谢
参考文献
[1] 刘惟信 汽车设计[M]北京清华学出版社2001
[2] 郭新华汽车构造[M]北京高等教育出版社2004
[3] 余志生汽车理[M]北京：机械工业出版社2010
[4] 学迅邓亚东汽车设计[M]北京：民交通出版社2008
[5] 王黎钦陈铁鸣机械设计[M]哈尔滨：哈尔滨工业学出版社2008
[6] 孙恒陈作模葛文杰机械原理[M] 北京高等教育出版社2006
[7] 张景田季雅娟丁建梅画法机械制图[M]哈尔滨：哈尔滨工业学出版社2005
[8] 刘品李哲机械精度设计检测基础[M]哈尔滨：哈尔滨工业学出版社2009
[9] 王宝玺贾庆祥汽车制造工艺学[M] 北京：机械工业出版社2007
[10] 江洪李仲兴陆利锋CATIA基础教程[M] 北京：机械工业出版社2005
[11] 施建胡建杰CATIA造型设计项目案例解析 北京清华学出版社2010
[12] HansHermann Braess Ulrich Seiffert Handbook of Automotive Engineering SAE International 2004
[13] James DHalderman Chase DMitchell Automotive technology principle diagnosis and service Pearson Education lnc 2004
短期课程
动变速器
查尔斯奥法里
现代动变速器迄止天汽车复杂机械部件动变速器包括机械系统液压系统电气系统计算机控制完美结合起没什问题文帮助您解里面技术奇迹修复失败时候什概念
文分五部分：
•什传输破简单传输目什
•传动部件描述系统般原理简单说帮助您解动变速器厂
•发现问题变更糟前表示寻求防止问题变成
•维护谈预防性维护应该知道
•传输修理修理通常轻微调整传输完成检修类型
________________________________________
传输什？
变速器连接面引擎发动机动力传递驱动轮装置汽车发动机处佳状态定转速运行（转分钟）范围传输工作确保动力传递驱动轮时保持该范围发动机通齿轮组合第轮发动机关系驱动轮速度更快高速运转发动机蛇王汽车会超70英里前进档变速器中立立场断开发动机驱动轮反驱动轮相反方转回停车位位置闩锁机制（门锁舌锁定）插入输出轴槽锁驱动轮阻止转动防止汽车移动
两种基类型动变速器车辆否轮驱动前轮驱动
轮驱动汽车变速器通常安装发动机端位底盘中心油门踏板位置驱动轴连接传输位桥终驱动动力传递轮功率流系统简单直接发动机通液力变矩器然通变速器传动轴直传动分送两车轮
传输什？
变速器连接面引擎发动机动力传递驱动轮装置汽车发动机处佳状态定转速运行（转分钟）范围传输工作确保动力传递驱动轮时保持该范围发动机通齿轮组合第轮发动机关系驱动轮速度更快高速运转发动机蛇王汽车会超70英里前进档变速器中立立场断开发动机驱动轮反驱动轮相反方转回停车位位置闩锁机制（门锁舌锁定）插入输出轴槽锁驱动轮阻止转动防止汽车移动
两种基类型动变速器车辆否轮驱动前轮驱动
轮驱动汽车变速器通常安装发动机端位底盘中心油门踏板位置驱动轴连接传输位桥终驱动动力传递轮功率流系统简单直接发动机通液力变矩器然通变速器传动轴直传动分送两车轮
前轮驱动汽车变速器通常结合形成谓终驱动桥前轮驱动汽车发动机通常安装车侧跨桥塞面汽车部发动机侧前车轴直接连接驱动桥提供电力前轮例子中功率流发动机通液力变矩器型链条动力通180度转传动侧发动机里权力传输驱动器分裂通传动轴传递两前轮
安排包括前轮驱动车辆发动机安装前横着系统四轮驱动两种系统目前受欢迎太常见驱布置变速器直接安装驱动器部传动轴扭矩转换器然安装发动机连接系统新出厂发现衡重量均匀前轮轮间改进性处理轮驱动系统安装切发动机传输终驱动器面发动机置布置流行保时捷
________________________________________
传动部件
现代动变速器设计巧妙机械交响乐团起工作许部件系统液压电气技术年发展许机械倾认种艺术形式尝试简单通解释描述系统复杂组件您需视化操作
组成动变速器部件包括：
•行星齿轮组提供前进档倒档机械系统
•液压系统采种特殊传动液泵压力通阀体控制离合器带控制行星齿轮组
•密封件垫片机油里应该防止漏油
•液力变矩器离合器允许车辆齿轮停止发动机运行
•调节器节流阀电缆监测速度节气门位置确定时移
•新型车辆换挡点计算机引导电螺线改变油流适组件正确时控制
行星齿轮组
前轮驱动汽车变速器通常结合形成谓终驱动桥前轮驱动汽车发动机通常安装车侧跨桥塞面汽车部发动机侧前车轴直接连接驱动桥提供电力前轮例子中功率流发动机通液力变矩器型链条动力通180度转传动侧发动机里权力传输驱动器分裂通传动轴传递两前轮
安排包括前轮驱动车辆发动机安装前横着系统四轮驱动两种系统目前受欢迎太常见驱布置变速器直接安装驱动器部传动轴扭矩转换器然安装发动机连接系统新出厂发现衡重量均匀前轮轮间改进性处理轮驱动系统安装切发动机传输终驱动器面发动机置布置流行保时捷
________________________________________
传动部件
现代动变速器设计巧妙机械交响乐团起工作许部件系统液压电气技术年发展许机械倾认种艺术形式尝试简单通解释描述系统复杂组件您需视化操作
组成动变速器部件包括：
•行星齿轮组提供前进档倒档机械系统
•液压系统采种特殊传动液泵压力通阀体控制离合器带控制行星齿轮组
•密封件垫片机油里应该防止漏油
•液力变矩器离合器允许车辆齿轮停止发动机运行
•调节器节流阀电缆监测速度节气门位置确定时移
•新型车辆换挡点计算机引导电螺线改变油流适组件正确时控制
行星齿轮组
动变速器包括许齿轮组合手动变速箱齿轮轴滑动移动换挡杆位置事种齿轮求提供正确传动然动变速器中齿轮移动保持啮合通行星齿轮组完成
基行星齿轮装置太阳轮齿圈两两行星齿轮剩余常啮合行星齿轮连接彼通载体齿轮旋转轴称齿轮附着载体
种方式该系统应例子连接齿圈发动机输入轴连接行星架输出轴锁定太阳齿轮动种情况转动齿圈行星走着太阳轮（
固定）导致行星架转动输出轴方输入轴速度较慢速度导致齿轮减速（类似汽车第齿轮）
果解开太阳齿轮锁两元素导致三素相速度输出轴速度作输入轴转率辆汽车第三高齿轮种方式行星齿轮组行星架固定移动然运权力环带动太阳轮反倒档齿轮
右边图显示述简单系统实际传输输入轴连接环形齿轮（蓝色）输出轴行星架（绿色）单离合器
单离合器（称斜撑离合器）种装置允许组件环形齿轮转方种效果样行车踏板车轮前蹬踏旋时蹬
单离合器第齿轮时移相器驱动位置开始加速停止开始第齿轮传动没注意果释放气体然第轮会发生什？汽车继续滑行仿佛中性现切换低速齿轮代开车停止加油种情况会感觉发动机放慢标准移动车驱动单离合器低离合器者带
乐队
种带种摩擦材料表面钢表带该带端固定变速器壳体端连接伺服适时间液压油送伺服压力收紧带滚筒停止滚筒转动
液力变矩器
动变速器液力变矩器标准换档车辆离合器方存发动机继续运行车辆停止时液力变矩器原理扇插入吹风扇果抓住拔掉风扇叶片举行放手会开始加速直接风扇转速动力液力变矩器空气油传动液更精确
液力变矩器种形装置炸圈饼（1015直径）安装发动机变速器间三部元素起发射功率传输变矩器三素泵涡轮定子泵直接安装转换器壳体次直接连接发动机曲轴发动机转速转涡轮机房屋直接连接传输提供动力驱动车辆输入轴定子安装单离合器旋转方三种元素鳍安装正直接通变矩器油流
发动机运转时传动液进入泵部分离心力外推直转动涡轮流体断循环运动回定子涡轮中心果涡轮速度低泵液体会定子定子翅片推单离合器前接触阻止旋转停止定子液体叶轮重新泵帮助角度提供扭矩增加涡轮速度赶泵流体开始攻击静子叶片造成定子方转动泵涡轮背面着速度增加三素开始转约相速度
年代提高燃油济性变矩器配备锁止离合器（未显示）锁定涡轮泵车辆速度达约45 50英里锁定计算机控制通常会进行非第三第四齿轮传动
液压系统
液压系统复杂通道发送传输流体压力传动液力变矩器部件迷宫左边图3速动60年代简单新系统更复杂结合计算机电气元件传动液项途包括：变速控制般润滑冷变速器发动机采油润滑传输功方面压力赖断提供液体类循环系统（液体甚红色）甚分钟操作时缺乏压力害传输生活甚致命保持变速器正常工作温度流体部分通两钢专室THA派
A Short Course on
Automatic Transmissions
by Charles Ofria
The modern automatic transmission is by far the most complicated mechanical component in today＇s automobile Automatic transmissions contain mechanical systems hydraulic systems electrical systems and computer controls all working together in perfect harmony which goes virtually unnoticed until there is a problem This article will help you understand the concepts behind what goes on inside these technological marvels and what goes into repairing them when they fail
This article is broken down into five sections
· What is a transmission breaks down in the simplest terms what the purpose of a transmission is
· Transmission Components describes the general principals behind each system in simple terms to help you understand how an automatic transmission works
· Spotting problems before they get worse shows what to look for to prevent a minor problem from becoming major
· Maintenance talks about preventative maintenance that everyone should know about
· Transmission repairs describes the types of repairs that are typically performed on transmissions from minor adjustments to complete overhauls
What is a transmission
The transmission is a device that is connected to the back of the engine and sends the power from the engine to the drive wheels An automobile engine runs at its best at a certain RPM (Revolutions Per Minute) range and it is the transmission＇s job to make sure that the power is delivered to the wheels while keeping the engine within that range It does this through various gear combinations In first gear the engine turns much faster in relation to the drive wheels while in high gear the engine is loafing even though the car may be going in excess of 70 MPH In addition to the various forward gears a transmission also has a neutral position which disconnects the engine from the drive wheels and reverse which causes the drive wheels to turn in the opposite direction allowing you to back up Finally there is the Park position In this position a latch mechanism (not unlike a deadbolt lock on a door) is inserted into a slot in the output shaft to lock the drive wheels and keep them from turning thereby preventing the vehicle from rolling
There are two basic types of automatic transmissions based on whether the vehicle is rear wheel drive or front wheel drive
On a rear wheel drive car the transmission is usually mounted to the back of the engine and is located under the hump in the center of the floorboard alongside the gas pedal position A drive shaft connects the rear of the transmission to the final drive which is located in the rear axle and is used to send power to the rear wheels Power flow on this system is simple and straight forward going from the engine through the torque converter then through the transmission and drive shaft until it reaches the final drive where it is split and sent to the two rear wheels
On a front wheel drive car the transmission is usually combined with the final drive to form what is called a transaxle The engine on a front wheel drive car is usually mounted sideways in the car with the transaxle tucked under it on the side of the engine facing the rear of the car Front axles are connected directly to the transaxle and provide power to the front wheels In this example power flows from the engine through the torque converter to a large chain that sends the power through a 180 degree turn to the transmission that is along side the engine From there the power is routed through the transmission to the final drive where it is split and sent to the two front wheels through the drive axles
There are a number of other arrangements including front drive vehicles where the engine is mounted front to back instead of sideways and there are other systems that drive all four wheels but the two systems described here are by far the most popular A much less popular rear drive arrangement has the transmission mounted directly to the final drive at the rear and is connected by a drive shaft to the torque converter which is still mounted on the engine This system is found on the new Corvette and is used in order to balance the weight evenly between the front and rear wheels for improved performance and handling Another rear drive system mounts everything the engine transmission and final drive in the rear This rear engine arrangement is popular on the Porsche
Transmission Components
The modern automatic transmission consists of many components and systems that are designed to work together in a symphony of clever mechanical hydraulic and electrical technology that has evolved over the years into what many mechanically inclined individuals consider to be an art form We try to use simple generic explanations where possible to describe these systems but due to the complexity of some of these components you may have to use some mental gymnastics to visualize their operation
The main components that make up an automatic transmission include
· Planetary Gear Sets which are the mechanical systems that provides the various forward gear ratios as well as reverse
· The Hydraulic System which uses a special transmission fluid sent under pressure by an Oil Pump through the Valve Body to control the Clutches and the Bands in order to control the planetary gear sets
· Seals and Gaskets are used to keep the oil where it is supposed to be and prevent it from leaking out
· The Torque Converter which acts like a clutch to allow the vehicle to come to a stop in gear while the engine is still running
· The Governor and the Modulator or Throttle Cable that monitor speed and throttle position in order to determine when to shift
· On newer vehicles shift points are controlled by Computer which directs electrical solenoids to shift oil flow to the appropriate component at the right instant
Planetary Gear Sets
Automatic transmissions contain many gears in various combinations In a manual transmission gears slide along shafts as you move the shift lever from one position to another engaging various sized gears as required in order to provide the correct gear ratio In an automatic transmission however the gears are never physically moved and are always engaged to the same gears This is accomplished through the use of planetary gear sets
The basic planetary gear set consists of a sun gear a ring gear and two or more planet gears all remaining in constant mesh The planet gears are connected to each other through a common carrier which allows the gears to spin on shafts called pinions which are attached to the carrier
One example of a way that this system can be used is by connecting the ring gear to the input shaft coming from the engine connecting the planet carrier to the output shaft and locking the sun gear so that it can＇t move In this scenario when we turn the ring gear the planets will walk along the sun gear (which is held stationary) causing the planet carrier to turn the output shaft in the same direction as the input shaft but at a slower speed causing gear reduction (similar to a car in first gear)
If we unlock the sun gear and lock any two elements together this will cause all three elements to turn at the same speed so that the output shaft will turn at the same rate of speed as the input shaft This is like a car that is in third or high gear Another way that we can use a Planetary gear set is by locking the planet carrier from moving then applying power to the ring gear which will cause the sun gear to turn in the opposite direction giving us reverse gear
The illustration on the right shows how the simple system described above would look in an actual transmission The input shaft is connected to the ring gear (Blue) The Output shaft is connected to the planet carrier (Green) which is also connected to a Multidisk clutch pack The sun gear is connected to a drum (yellow) which is also connected to the other half of the clutch pack Surrounding the outside of the drum is a band (red) that can be tightened around the drum when required to prevent the drum with the attached sun gear from turning
The clutch pack is used in this instance to lock the planet carrier with the sun gear forcing both to turn at the same speed If both the clutch pack and the band were released the system would be in neutral Turning the input shaft would turn the planet gears against the sun gear but since nothing is holding the sun gear it will just spin free and have no effect on the output shaft To place the unit in first gear the band is applied to hold the sun gear from moving To shift from first to high gear the band is released and the clutch is applied causing the output shaft to turn at the same speed as the input shaft
Many more combinations are possible using two or more planetary sets connected in various ways to provide the different forward speeds and reverse that are found in modern automatic transmissions
Some of the clever gear arrangements found in four and now five six and even seven and eightspeed automatics are complex enough to make a technically astute lay person＇s head spin trying to understand the flow of power through the transmission as it shifts from first gear through top gear while the vehicle accelerates to highway speed On modern vehicles (mid ＇80s to the present) the vehicle＇s computer monitors and controls these shifts so that they are almost imperceptible
Clutch Packs
A clutch pack consists of alternating disks that fit inside a clutch drum Half of the disks are steel and have splines that fit into groves on the inside of the drum The other half have a friction material bonded to their surface and have splines on the inside edge that fit groves on the outer surface of the adjoining hub There is a piston inside the drum that is activated by oil pressure at the appropriate time to squeeze the clutch pack together so that the two components become locked and turn as one
OneWay Clutch
A oneway clutch (also known as a sprag clutch) is a device that will allow a component such as ring gear to turn freely in one direction but not in the other This effect is just like that of a bicycle where the pedals will turn the wheel when pedaling forward but will spin free when pedaling backward
A common place where a oneway clutch is used is in first gear when the shifter is in the drive position When you begin to accelerate from a stop the transmission starts out in first gear But have you ever noticed what happens if you release the gas while it is still in first gear The vehicle continues to coast as if you were in neutral Now shift into Low gear instead of Drive When you let go of the gas in this case you will feel the engine slow you down just like a standard shift car The reason for this is that in Drive a oneway clutch is used whereas in Low a clutch pack or a band is used
Bands
A band is a steel strap with friction material bonded to the inside surface One end of the band is anchored against the transmission case while the other end is connected to a servo At the appropriate time hydraulic oil is sent to the servo under pressure to tighten the band around the drum to stop the drum from turning
Torque Converter
On automatic transmissions the torque converter takes the place of the clutch found on standard shift vehicles It is there to allow the engine to continue running when the vehicle comes to a stop The principle behind a torque converter is like taking a fan that is plugged into the wall and blowing air into another fan which is unplugged If you grab the blade on the unplugged fan you are able to hold it from turning but as soon as you let go it will begin to speed up until it comes close to the speed of the powered fan The difference with a torque converter is that instead of using air it uses oil or transmission fluid to be more precise
A torque converter is a large doughnut shaped device (10 to 15 in diameter) that is mounted between the engine and the transmission It consists of three internal elements that work together to transmit power to the transmission The three elements of the torque converter are the Pump the Turbine and the Stator The pump is mounted directly to the converter housing which in turn is bolted directly to the engine＇s crankshaft and turns at engine speed The turbine is inside the housing and is connected directly to the input shaft of the transmission providing power to move the vehicle The stator is mounted to a oneway clutch so that it can spin freely in one direction but not in the other Each of the three elements have fins mounted in them to precisely direct the flow of oil through the converter
With the engine running transmission fluid is pulled into the pump section and is pushed outward by centrifugal force until it reaches the turbine section which starts it turning The fluid continues in a circular motion back towards the center of the turbine where it enters the stator If the turbine is moving considerably slower than the pump the fluid will make contact with the front of the stator fins which push the stator into the one way clutch and prevent it from turning With the stator stopped the fluid is directed by the stator fins to reenter the pump at a helping angle providing a torque increase As the speed of the turbine catches up with the pump the fluid starts hitting the stator blades on the backside causing the stator to turn in the same direction as the pump and turbine As the speed increases all three elements begin to turn at approximately the same speed
Since the ＇80s in order to improve fuel economy torque converters have been equipped with a lockup clutch (not shown) which locks the turbine to the pump as the vehicle speed reaches approximately 45 50 MPH This lockup is controlled by computer and usually won＇t engage unless the transmission is in 3rd or 4th gear
Hydraulic System
The Hydraulic system is a complex maze of passages and tubes that sends transmission fluid under pressure to all parts of the transmission and torque converter The diagram at left is a simple one from a 3speed automatic from the ＇60s The newer systems are much more complex and are combined with computerized electrical components Transmission fluid serves a number of purposes including shift control general lubrication and transmission cooling Unlike the engine which uses oil primarily for lubrication every aspect of a transmission＇s functions is dependant on a constant supply of fluid under pressure This is not unlike the human circulatory system (the fluid is even red) where even a few minutes of operation when there is a lack of pressure can be harmful or even fatal to the life of the transmission In order to keep the transmission at normal operating temperature a portion of the fluid is sent through one of two steel tubes to a special chamber that is submerged in antifreeze in the radiator Fluid passing through this chamber is cooled and then returned to the transmission through the other steel tube A typical transmission has an average of ten quarts of fluid between the transmission torque converter and cooler tank In fact most of the components of a transmission are constantly submerged in fluid including the clutch packs and bands The friction surfaces on these parts are designed to operate properly only when they are submerged in oil
Oil Pump
The transmission oil pump (not to be confused with the pump element inside the torque converter) is responsible for producing all the oil pressure that is required in the transmission The oil pump is mounted to the front of the transmission case and is directly connected to a flange on the torque converter housing Since the torque converter housing is directly connected to the engine crankshaft the pump will produce pressure whenever the engine is running as long as there is a sufficient amount of transmission fluid available The oil enters the pump through a filter that is located at the bottom of the transmission oil pan and travels up a pickup tube directly to the oil pump The oil is then sent under pressure to the pressure regulator the valve body and the rest of the components as required
Valve Body
The valve body is the control center of the automatic transmission It contains a maze of channels and passages that direct hydraulic fluid to the numerous valves which then activate the appropriate clutch pack or band servo to smoothly shift to the appropriate gear for each driving situation Each of the many valves in the valve body has a specific purpose and is named for that function For example the 23 shift valve activates the 2nd gear to 3rd gear upshift or the 32 shift timing valve which determines when a downshift should occur
The most important valve and the one that you have direct control over is the manual valve The manual valve is directly connected to the gear shift handle and covers and uncovers various passages depending on what position the gear shift is placed in When you place the gear shift in Drive for instance the manual valve directs fluid to the clutch pack(s) that activates 1st gear It also sets up to monitor vehicle speed and throttle position so that it can determine the optimal time and the force for the 1 2 shift On computer controlled transmissions you will also have electrical solenoids that are mounted in the valve body to direct fluid to the appropriate clutch packs or bands under computer control to more precisely control shift points
Computer Controls
The computer uses sensors on the engine and transmission to detect such things as throttle position vehicle speed engine speed engine load brake pedal position etc to control exact shift points as well as how soft or firm the shift should be Once the computer receives this information it then sends signals to a solenoid pack inside the transmission The solenoid pack contains several electrically controlled solenoids that redirect the fluid to the appropriate clutch pack or servo in order to control shifting Computerized transmissions even learn your driving style and constantly adapt to it so that every shift is timed precisely when you would need it
Because of computer controls sports models are coming out with the ability to take manual control of the transmission as though it were a stick shift allowing the driver to select gears manually This is accomplished on some cars by passing the shift lever through a special gate then tapping it in one direction or the other in order to upshift or downshift at will The computer monitors this activity to make sure that the driver does not select a gear that could over speed the engine and damage it
Another advantage to these smart transmissions is that they have a self diagnostic mode which can detect a problem early on and warn you with an indicator light on the dash A technician can then plug test equipment in and retrieve a list of trouble codes that will help pinpoint where the problem is
Governor Vacuum Modulator Throttle Cable
These three components are important in the noncomputerized transmissions They provide the inputs that tell the transmission when to shift The Governor is connected to the output shaft and regulates hydraulic pressure based on vehicle speed It accomplishes this using centrifugal force to spin a pair of hinged weights against pullback springs As the weights pull further out against the springs more oil pressure is allowed past the governor to act on the shift valves that are in the valve body which then signal the appropriate shifts
Of course vehicle speed is not the only thing that controls when a transmission should shift the load that the engine is under is also important The more loads you place on the engine the longer the transmission will hold a gear before shifting to the next one
There are two types of devices that serve the purpose of monitoring the engine load the Throttle Cable and the Vacuum Modulator A transmission will use one or the other but generally not both of these devices Each works in a different way to monitor engine load
The Throttle Cable simply monitors the position of the gas pedal through a cable that runs from the gas pedal to the throttle valve in the valve body
The Vacuum Modulator monitors engine vacuum by a rubber vacuum hose which is connected to the engine Engine vacuum reacts very accurately to engine load with high vacuum produced when the engine is under light load and diminishing down to zero vacuums when the engine is under a heavy load The modulator is attached to the outside of the transmission case and has a shaft which passes through the case and attaches to the throttle valve in the valve body When an engine is under a light load or no load high vacuum acts on the modulator which moves the throttle valve in one direction to allow the transmission to shift early and soft As the engine load increases vacuum is diminished which moves the valve in the other direction causing the transmission to shift later and more firmly
Seals and Gaskets
An automatic transmission has many seals and gaskets to control the flow of hydraulic fluid and to keep it from leaking out There are two main external seals the front seal and the rear seal The front seal seals the point where the torque converter mounts to the transmission case This seal allows fluid to freely move from the converter to the transmission but keeps the fluid from leaking out The rear seal keeps fluid from leaking past the output shaft
A seal is usually made of rubber (similar to the rubber in a windshield wiper blade) and is used to keep oil from leaking past a moving part such as a spinning shaft In some cases the rubber is assisted by a spring that holds the rubber in close contact with the spinning shaft
A gasket is a type of seal used to seal two stationary parts that are fastened together Some common gasket materials are paper cork rubber silicone and soft metal
Aside from the main seals there are also a number of other seals and gaskets that vary from transmission to transmission A common example is the rubber Oring that seals the shaft for the shift control lever This is the shaft that you move when you manipulate the gear shifter Another example that is common to most transmissions is the oil pan gasket In fact seals are required anywhere that a device needs to pass through the transmission case with each one being a potential source for leaks
文档香网(httpswwwxiangdangnet)户传
《香当网》用户分享的内容，不代表《香当网》观点或立场，请自行判断内容的真实性和可靠性！
该内容是文档的文本内容，更好的格式请下载文档
毕业设计
题 目 三轴五档手动变速器设计
专 业 机械设计制造动化
学 号
学 生
指导教师
答辩日期 2014
摘
设计务设计台轿车五档手动变速器合理设计布置变速器发动机功率合理利提高汽车动力性济性变速传动机构作改变转距转速数值方操机构作控制传动机构实现变速器传动改变实现换挡达变速变距
文参阅国外量文献首先简单叙述机械式变速器发展历史变速器位作讨现状未发展趋势进研究机械式变速器基结构变速原理中重点研究传动机构（轴齿轮）基结构特点工作原理机械式变速器挡传动路线进行简分析文章包括量计算程具体容：变速器布置方案分析变速器回转件结构参数确定步器结构工作原理挡齿轮强度校核轴强度校核轴承寿命计算等
关键词 齿轮步器变速器
Abstract
This design task is to design a car for five manual shift transmission Reasonable design and decorate transmission can make the engine power to get the most reasonable use of so as to improve the dynamic performance and fuel economy cars Variable speed transmission＇s main function is to change the torque and speed of numerical and direction Operation is the main purpose of control transmission mechanism realize the transmission ratio of the gearbox change which realize the shift in order to achieve the change from the speed
This article refer to the domestic and foreign many papers and first simply describes the mechanical transmission of the history the status and effect of the transmission and discussed its present situation and future development trend And then we study the basic structure of the mechanical transmission and variable speed principle which focus on the transmission mechanism (mainly shaft and gear) the basic structure characteristic and work principle mechanical transmission of each block transmission line are briefly analyzed The articles included a large amount of calculation process and the specific contents the layout of transmission analysis the transmission structure paramete determination of turning a synchronizer the structure and the working principle each block of the gear axis strength check the intensity the service life of the bearings calculations etc
Keywords Gear Shaft Synchronizer Three axis five gear
目 录
摘 I
Abstract II
第1章 绪 1
11 设计目意义 1
12 变速器发展 1
13变速器设计求 3
14设计容思路 3
141设计容 3
142设计思路 4
15章结 4
第2章 变速器整体结构方案设计 5
21变速器传动机构型式选择结构分析 5
211变速器传动方案较 5
212倒档布置方案 6
22章结 7
第3章 变速器参数选择齿轮设计 9
31变速器参数选择 9
311档位数传动 9
312中心距 10
313齿轮模数 11
314压力角α螺旋角β齿宽b 12
315齿轮变位系数 13
32档传动齿轮齿数确定 13
321确定档齿轮齿数 13
322确定常啮合齿轮副齿数 14
323确定档位齿数 15
324确定倒档齿轮齿数 15
325确定齿轮轮齿尺寸 15
33章结 16
第4章 变速器齿轮强度计算材料选择 17
41齿轮失效形式 17
42齿轮强度计算材料接触应力 17
421齿轮弯曲强度计算 17
422齿轮材料接触应力 19
43章结 21
第5章 变速器轴设计校核 22
51变速器轴结构尺寸 22
511轴结构 22
512轴尺寸 22
52轴校核 23
521第轴强度刚度校核 23
522第二轴强度刚度校核 24
53章结 26
第6章 变速器步器操机构设计 27
61步器设计 27
611步器工作原理 27
612步环参数确定 28
62变速器操机构 30
621操机构功 30
622操机构设计求 31
623变速器换档位置 32
63章结 32
第7章 轴承选寿命计算 33
71 第轴轴承选计算 33
72第二轴轴承选计算 33
73章结 34
结 41
致 谢 42
参考文献 43
第1章 绪
11 设计目意义
着国汽车工业断壮汽车行业持续快速发展设计出济实惠工作性优良汽车已前汽车设计者紧迫问题发挥发动机佳性必须套传动效率高维修保养成低够带驾驶乐趣变速装置协调发动机转速车轮实际行驶速度
该课题针机械专业学生学生解变速器设计通课题研究学生完成理课程实践总结获定工程设计工作方法更学掌握现代汽车设计机械设计全面知识锻炼学生利学知识分析问题解决问题力
12 变速器发展
汽车变速箱100年历史中历手动动发展程目前世界汽车变速器手动变速器（MT）动变速器（AT）手体变速器（AMT）级变速器（CVT）双离合变速器（DCT）五种型式
（1）手动变速器(MT)
手动变速器（Manual Transmission）采齿轮组档齿轮组齿数固定档变速定值断言繁琐驾驶操作等缺点阻碍汽车高速发展步伐手动变速器会久淘汰事物发展角度说话确实道理目前市场需求适角度手动变速器会早离开首先商车特性说手动变速器功变速器代次老司机部分男士司机说爱手动变速器第三着生活水断提高现轿车已进入家庭普通工薪阶级老百姓说济型轿车合适手动变速器身性价配套济型轿车厂家济适型轿车销量直车市名列前茅
（2）动变速器（AT）
动变速器（AutomaticTransmission）利行星齿轮机构进行变速根油门踏板程度车速变化动进行变速驾驶者需操加速踏板控制车速说动变速汽车没离合器动变速器中离合器离合器车速变化动分离合闭达动变速目
（3）手动动变速器（AMT）
型车档位设+选择档位D档时变换降档()加档(+)手动档样动—手动变速系统提供两种驾驶方式—驾驶乐趣手动档交通拥挤时动档样变速方式国现状非常适合
（4）级变速器（CVT）
汽车产业发展非常迅速户汽车性求越越高汽车变速器发展仅限级变速器便追求高境界级变速系统手动变速器动变速器样齿轮变速两滑轮钢带变速传动意变化没换档突跳感觉克服普通动变速器突然换档油门反应慢油耗高等缺点
（5）双离合变速器（DCT）
DCT结合手动变速器燃油济性动变速器舒适性传统手动变速器演变目前代表变速器高技术双离合变速器(Dual Clutch Transmission) DCT般动变速器系统基手动变速器动变速器拥手动变速器灵活性动变速器舒适性外提供间断动力输出传统手动变速器台离合器换挡时驾驶员须踩离合器踏板挡齿轮做出啮合动作动力换挡期间出现间断令输出表现断续
针中国变速器市场发展趋势Global Insight亚洲区技术分析师段诚武博士阐述点见解：
（1）短期手动档变速器然占份额动档变速器更增长空间
（2）鉴中国市场情况复杂性长期变速器单式发展趋势没种形式变速器会成赢家
（3）中国市场技术支持目前市场份额设备提供方面AMTLPGAUTOE汽油CVTE混合动力DCT柴油具相似性
（4）长远中国土企业应该更加关注DCT产品非常前景
13变速器设计求
（1）应保证汽车具高动力性济性指标汽车整体设计时根汽车载重量发动机参数汽车求选择合理变速器挡数传动满足求
（2）工作操轻便汽车行驶程中变速器应动跳挡乱挡换挡击等现象发生减轻驾驶员疲劳强度提高行驶安全性操轻便求日益显重通采步器预选气动换挡动半动换挡实现
（3）重量轻体积影响指标参数变速器中心距选优质钢材采合理热处理设计合适齿形提高齿轮精度选圆锥滚柱轴承减中心距
（4）传动效率高减齿轮啮合损失应直接挡提高零件制造精度安装质量采适润滑油提高传动效率
（5）噪声采斜齿轮传动选择合理变位系数提高制造精度安装刚性减齿轮噪声
14设计容思路
141设计容
1齿轮参数选择设计校核计算
2齿轮轴设计校核计算
3步器设计计算
4轴承选择设计校核计算
5CATIA软件进行三维建模
142设计思路
查变速器相关资料理解变速器结构组成工作原理先变速器进行整体布置包括整体传动方案倒档布置次次变速器中齿轮轴进行设计计算确定齿轮轴尺寸CAD进行草图绘制基础步器进行设计计算进步完善草图部分进行校核计算查尺寸否满足求果正确进行修改着重分析步器操机构工作原理进行细化处理出张操机构图纸CAD二维图纸绘制完成CATIA软件进行三维建模仿真运动立体结构更直观变速器呈现出部机构配合更清楚
15章结
章变速器发展历史未方进行初步解手动变速器未较乐观巨市场章明确该设计目意义设计会严格目做保证会偏离方变速器设计求需严格遵守直接关系变速器安全性舒适性次设计设计容设计思路进行展开进步明确设计方案
第2章 变速器整体结构方案设计
21变速器传动机构型式选择结构分析
变速器种类传动改变方式分级级综合式级变速器根前进档档数分三四五档档变速器轴中心线位置分固定轴线式螺旋轴线式综合式中固定轴式应广泛两轴式三轴式分前者发动机前置前轮驱动汽车者发动机前置轮驱动汽车
211变速器传动方案较
图23三轴式五档变速器传动方案特点：变速器第轴第二轴轴线直线啮合套连接直接档直接档变速器齿轮轴承中间轴均承载发动机转矩变速器第轴第二轴直接输出时变速器传动效率高达90噪声低齿轮轴承磨损减少直接档利率高档位提高变速器寿命前进档位工作时变速器传递动力需设置第轴中间轴第二轴两齿轮传递变速器中间轴第二轴间距离（中心距）条件档然较传动档位高齿轮采常啮合齿轮传动档位低齿轮（档）采采常啮合齿轮传动数传动方案中档外档位换档机构均采步器啮合套换档少数结构档采步器啮合套换档档步器啮合套数情况装第二轴直接档外档位工作时三轴式变速器传动效率略降低缺点档数相条件种三轴式变速器常啮合齿轮数换档方式倒档传动方案差
图23a示方案倒档直齿滑动齿轮换档外余档常啮合齿轮传动图23bcd示方案前进档均常啮合齿轮传动
图23d示方案中倒档超速档安装位变速器部副箱体样布置提高轴刚度减少齿轮磨损降低工作噪声外需超速档条件形成四前进档变速器
图23
种方案中采常啮合齿轮传动档位换档方式步器啮合套实现变速器中档位步器换档档位啮合套换档定档位高步器换档档位低啮合套换档
变速器图23c示支承结构方案提高轴刚度时轴面分开壳体较解决轴齿轮等零部件装配困难问题图23c示方案高档动齿轮处悬臂状态时档倒档齿轮布置变速器壳体中间跨距里中间档步器布置中间轴方案特点
设计采23b布置方案
212倒档布置方案
常见倒档结构方案种：
图24a常见倒挡布置方案前进档传动路线中加入传动结构简单齿轮处正负交称变化弯曲应力状态工作方案广泛轿车轻型货车四档全步器式变速器中
图24b示方案优点换倒挡时利中间轴挡齿轮缩短中间轴长度换挡时两齿轮时进入啮合换挡困难某轻型货车四档变速器采方案
图24c示方案获较倒挡传动缺点换挡程序合理
图24d示方案针前者缺点做修改常货车变速器中
图24e示方案中间轴倒挡齿轮做成体齿宽加长
图24f示方案适全部齿轮副均常啮合齿轮换挡更轻便
充分利空间缩短变速器轴长度货车倒挡传动采图24g示方案缺点倒挡须根变速器拨叉轴致变速器盖中操机构复杂
图24
综合考虑次设计采图24f示方案倒档换档方式
22章结
章分析较变速器传动机构形式结构着重分析动力布置形式倒档形式分析结构进行明确动力传递路线更合理布置档位选取传动更加简单倒档布置方式面设计计算基础
第3章 变速器参数选择齿轮设计
设计根 Polo 2011款劲取 16 MT实酷版开展设计中采相关参数均源种车型表31示：
表31
减速
316
扭矩
155Nm3750rpm
高时速
188kmh
功率
77kw5000rpm
轮胎型号
18560R15
发动机型号
EA111
整备质量
1155Kg
31变速器参数选择
311档位数传动
降低油耗提高燃油利率变速器档数应该适增加目前车般45档位变速器设计采5档位
选择低档传动时应根汽车爬坡度驱动轮路面附着力汽车低稳定车速减速驱动轮滚动半径等综合考虑确定
汽车爬陡坡时车速高空气阻力忽略驱动力克服轮胎路面间滚动阻力爬坡阻力
（31）
爬坡度求变速器Ⅰ档传动
（32）
式中 m——汽车总质量
g ——重力加速度
ψmax ——道路阻力系数
rr ——驱动轮滚动半径
Temax ——发动机转矩
i0——减速
η ——汽车传动系传动效率
根驱动车轮路面附着条件
求变速器I档传动：
（33）
式中 G2——汽车满载静止水路面时驱动桥路面载荷
φ ——路面附着系数计算时取φ0506
已知条件：满载质量 1530kgrr286mmη095f003
根公式（33）：igI 348
超速档传动：
(34)
已知条件：
中间档传动理公：
（35）
等数列实际理略出入齿数整数常档位间公宜外考虑发动机参数合理匹配根式出：1398
：（修正1）
312中心距
中心距变速器尺寸质量直接影响选中心距应保证齿轮强度三轴式变速器中心距A根已变速器统计出验公式进行初选
（36）
式中K A ——中心距系数轿车取K A 89~93（取92）
TI max ——变速器处档时输出轴输出扭矩：
TI maxTe max igI η 5178N﹒m
出初始中心距A7388mm
313齿轮模数
齿轮模数选取般原：
(1)减少噪声应合理减模数时增加齿宽
(2)质量应该增加模数时减少齿宽
(3)工艺方面考虑挡齿轮应该选种模数
(4)强度方面考虑挡齿轮应模数
轿车减少工作噪声较重模数应选货车减质量减噪声更重模数应选
选模数值应符合国家标准规定
建议列式选取齿轮模数第轴常啮合斜齿轮法模数mn
（37）
中155Nm出mn252
档直齿轮倒档齿轮模数m
mm （38）
通计算m26
表32渐开线齿轮标准模数m （摘GBT13571987）mm
第系列
1 125 15 20 25 3 4 5 6 8 10
第二系列
175 225 275（325）35（375）45 55（65） 7 9
注：优先采第系列括号模数
：
314压力角α螺旋角β齿宽b
压力角较时重合度传动稳噪声低较时提高轮齿抗弯强度表面接触强度轿车加重合度已降低噪声取货车提高齿轮承载力取设计中变速器齿轮压力角α取国家规定标准压力角20°
变速器斜齿轮螺旋角般范围螺旋角增齿轮啮合重合度系数增加工作稳噪声降低外齿轮强度提高螺旋角太会轴力轴承载荷轿车变速器齿轮转速高求噪声螺旋角取较值应该注意选取斜齿轮螺旋角时候应该中间轴轴力衡第二轴轴力轴承盖壳体承受中间轴全部齿轮螺旋方应该律做成右旋第二轴齿轮做成左旋
齿轮宽度b直接影响着齿轮承载力b加齿承载力增高试验表明齿宽增定数值载荷分配均匀反齿轮承载力降低保证齿轮强度条件量选取较齿宽利减轻变速器重量缩短轴尺寸
通常根齿轮模数选定齿宽：
直齿 b(4575)mmm
斜齿 b(6585)mm
第轴常啮合齿轮副齿宽系数值取接触线长度增加接触应力降低提高传动稳性齿轮寿命
已知： m26
：常啮合齿轮齿宽取20mm235档齿轮齿宽取175mm倒档档齿轮齿宽取13mm
（注：保证装配接触宽度b通常取齿轮宽度b齿轮宽度b210mm强度计算时b）
315齿轮变位系数
变位齿轮两类：高度变位角度变位高度变位齿轮副啮合齿轮变位系数零高度变位增加齿轮齿根强度达齿轮强度想接程度高度变位齿轮副缺点时增加齿轮强度难降低噪声角度变位齿轮副变位系数等零角度变位获良啮合性传动质量指标采较
变位系数选择原 ：
(1)高档齿轮应保证接触强度抗胶合耐磨损利原选择变位系数
(2)低档齿轮提高齿轮齿根强度应根危险断面齿厚相等条件选择齿轮变位系数
(3)总变位系数越齿轮齿根抗弯强度越低易吸收击振动噪声
降低噪声变速器中二档外档齿轮总变位系数选较数值般情况着档位降低总变位系数应该逐档增二档倒档齿轮应该选较值
32档传动齿轮齿数确定
321确定档齿轮齿数
已知档动：
（39）
确定Z9Z10齿数先求齿数：
（310）
中 A 7388mmm 3选择齿轮齿数时应注意相配齿轮齿数偶数减少齿轮齿数间公约数机会否会引起齿面均匀磨损取57轿车三轴式变速器时处取18出39
面根初选Am计算出整数调整整数中心距变化时应齿轮变位系数反计算中心距A修正中心距作计算
里修正57根式（310）反推出A75mm
322确定常啮合齿轮副齿数
式（38）求出常啮合齿轮传动
（311）
已知数：
常啮合齿轮中心距档齿轮中心距相等斜齿轮中心距
（312）
：
（313）
根已知数计算出：
联立方程式：2033
计算出档实际传动实际螺旋角
323确定档位齿数
二档传动
（314）
（315）
：
联立方程式：
样方法分计算出：三档齿轮 五档齿轮
324确定倒档齿轮齿数
取Z22
A （316）
Z+Z58分配Z17Z40
倒挡轴中间轴中心距507mm
防止干涉1112齿轮齿顶圆保持05mm间隙
d906mm
325确定齿轮轮齿尺寸
齿顶高：
斜齿轮齿顶高25mm直齿轮齿顶高26mm
齿根高：
斜齿轮齿根高31mm直齿轮齿根高325mm
33章结
章变速器齿轮参数进行设计计算确定齿轮模数齿数压力角斜齿轮螺旋角等齿轮参数确定CATIA参数化建模提供利渐开线画法进行三维制图草图绘制确定分度圆直径
第4章 变速器齿轮强度计算材料选择
41齿轮失效形式
齿轮失效形式：轮齿折断齿面点蚀齿面磨损齿面胶合塑性形变
42齿轮强度计算材料接触应力
机械设备变速器较途汽车变速器齿轮条件相似外汽车变速器齿轮材料热处理方法加工方法精度等级支撑方式基致汽车变速器齿轮低碳合金钢制造采剃齿齿轮精加工齿轮表面采渗碳淬火热处理工艺齿轮精度低7级计算通齿轮强度公式更简化计算公式计算汽车齿轮样获较准确结果里选择齿轮材料40Cr
421齿轮弯曲强度计算
（1）直齿轮弯曲应力
（41）
式中 ——弯曲应力（MPa）
——档齿轮10圆周力（N） 中计算载荷（N·mm）d节圆直径
——应力集中系数似取165
——摩擦力影响系数动齿轮取11动齿轮取09
b ——齿宽（mm）
t ——端面齿距（mm）
y ——齿形系数图41示
图41 齿形系数图
处档时中间轴计算扭矩：
（42）
求 139500N
出出数代入式（41）
计算载荷取作变速器第轴扭矩时档直齿轮弯曲应力400850MPa间
（2）斜齿轮弯曲应力
（43）
式中 重合度影响系数取20参数均式（41）注释相选择齿形系数y时模数图（41）中查
二档齿轮圆周力：
（44）
根斜齿轮参数计算公式出：53701N
齿轮8齿数z22查表（41）：
求：
理：
计算二档齿轮方法出档位齿轮弯曲应力计算结果：
三档：
五档：
计算载荷取作第轴扭矩时常啮合齿轮高档齿轮许应力180350MPa范围
述直齿轮斜齿轮计算结果均符合弯曲强度求
422齿轮材料接触应力
齿轮接触应力
（45）
式中——齿轮接触应力（MPa）
F ——齿面法力（N）
——圆周力（N）
——节点处压力角（°）
——齿轮螺旋角（°）
E ——齿轮材料弹性模量（MPa）查资料取
B ——齿轮接触实际宽度
——动齿轮节点处曲率半径（mm）
直齿轮：
（46）
（47）
斜齿轮：
（48）
（49）
中分动齿轮节圆半径（mm）
作变速器第轴载荷作计算载荷时变速器齿轮许接触应力见表41：
表41
齿轮
MPa
渗碳齿轮
液体碳氮渗齿轮
档倒档
19002000
9501000
常啮合齿轮高档
13001400
650700
通计算出档齿轮接触应力分：
档：1849MPa二档：12064MPa三档：11915MPa
五档：12397MPa
表41知设计变速器齿轮接触应力基符合求
43章结
章分析齿轮失效形式设计齿轮进行强度接触应力计算通计算发现齿轮符合设计求够保证求齿轮校核计算时非常关键步检测前选取计算正确否防止更错误产生
第5章 变速器轴设计校核
51变速器轴结构尺寸
511轴结构
第轴通常齿轮做成体前端支撑飞轮腔轴承轴径根前轴承径确定该轴承承受轴力轴轴定位般轴承卡环轴承盖实现第轴长度离合器轴尺寸确定花键尺寸应离合器动盘毂花键统考虑第轴图51示：
图51 变速器第轴
中间轴分旋转轴式固定轴式设计采旋转轴式传动方案档倒档齿轮较通常中间轴做成体高档齿轮分键固定轴便齿轮磨损更换
512轴尺寸
变速器轴确定尺寸结构布置求考虑加工工艺装配工艺求定草图设计时齿轮换档部件工作位置尺寸初步确定轴长度轴直径参考类汽车变速器轴尺寸选定列验
第轴中间轴： （51）
第二轴： （52）
式中——发动机扭矩N·m
保证设计合理性轴强度刚度应定协调关系轴直径d轴长度L关系式选取：
第轴中间轴：dL016018
第二轴：dL018021
52轴校核
变速器结构布置考虑加工装配确定轴尺寸般说强度足够仅危险断面进行验算设计变速器说设计程中轴强度刚度留定余量进行校核时需校核档处车辆行进程中档传动扭矩轴承受扭矩第二轴结构较复杂作重点校核象面第轴第二轴进行校核
521第轴强度刚度校核
第轴运转程中受弯矩忽略认受扭矩中情况轴扭矩强度条件公式
（53）
式中 ——扭转切应力MPa
T ——轴受扭矩N·mm
——轴抗扭截面系数
P ——轴传递功率kw
d ——计算截面处轴直径mm
[] ——许扭转切应力MPa
中P 77kwn 5000rmind 30mm代入式：
查表知[]55MPa[]符合强度求
轴扭转变形米长扭转角表示计算公式：
（54）
式中 T ——轴受扭矩N·mm
G ——轴材料剪切弹性模量MPa钢材G 81MPa
——轴截面极惯性矩
已知数代入式：
般传动轴取符合刚度求
522第二轴强度刚度校核
（1）轴强度校核
计算齿轮啮合圆周力径力轴力式求出：
（55）
（56）
（57） 式中 ——计算齿轮传动处档传动348
d ——计算齿轮节圆直径1014mm
——节点处压力角20°
——螺旋角30°
——发动机转矩155000N·mm
代入式：
危险截面受力图：
图53 危险截面受力分析
水面：（160+83）83 出15272N
水面受力矩：
垂直面：
（58）
求出 57236N
垂直面受力矩：
该轴受扭矩：
危险截面受合成弯矩：
（59）
M
弯矩转矩联合作轴应力（MPa）：
（510）
代入式：低档工作时[]400MPa： 符合求
（2）轴刚度校核
第二轴垂直面挠度水面挠度分式计算：
（511）
（512）
式中 ——齿轮齿宽中间面径力（N）里等
——齿轮齿宽中间面圆周力（N）里等
E ——弹性模量（MPa）（MPa）
I ——惯性矩（）d轴直径（）
ab ——齿轮坐作力距支座AB距离（）
L ——支座间距离（）
数值代入式（511）（512）：
轴全挠度符合刚度求
53章结
章变速器轴进行设计计算第轴通常齿轮做成体中间轴选旋转式低档位齿轮轴做成体高档齿轮键轴连接传递扭矩第二较复杂面矩形花键选取设计轴进行校核计算满足实际求
第6章 变速器步器操机构设计
61步器设计
前面已说明设计采步器类型锁环式步器结构图61示：
图61 锁环式步器
19变速器齿轮 2滚针轴承 38结合齿圈 47锁环（步环）
5弹簧 6定位销 10花键毂 11结合套
611步器工作原理
图62类步器工作原理：换档时轴作啮合套换档力推啮合套带动定位销锁环移动直锁环锥面接合齿轮锥面接触止作锥面法力两锥面间存角速度差致锥面作摩擦力矩锁环相啮合套滑块转角度滑块予定位接啮合套齿端锁环齿端锁止面接触（图62b）啮合套移动受阻步器锁止状态换档第阶段结束换档力锁环继续压锥面摩擦力矩增时锁止面处作方相反拨环力矩齿轮锁环角速度逐渐角速度相等瞬间步程结束完成换档程第二阶段工作摩擦力矩消失拨环力矩锁环回位两锁止面分开步器解锁止状态接合套接合齿换档力作通锁环齿轮接合齿啮合（图62d）完成步换档
图62 锁环步器工作原理
612步环参数确定
(1)步环锥面螺纹槽
果螺纹槽螺线顶部设计窄刮存摩擦锥面间油膜效果顶部宽度窄会影响接触面压强磨损加快试验证明：螺纹齿顶宽摩擦数影响摩擦数齿顶磨损降低换挡费力齿顶宽易螺纹槽设计刮油存螺纹间间隙中螺距增会接触面减少增加磨损速度图63a中出尺寸适轻中型汽车图63b适重型汽车通常轴泄油槽6～12槽宽3～4mm
图63 步器螺纹槽形式
(2)锥面半锥角
摩擦锥面半锥角越摩擦力矩越摩擦锥面产生锁现象避免锁条件tan般6°～8°6°时摩擦力矩较锥面表面粗糙度控制严时粘着咬住倾时少出现咬住现象
次设计中采锥角均取7°
(3)摩擦锥面均半径R
R设计越摩擦力矩越R受结构限制包括变速器中心距相关零件尺寸布置限制R取会影响步环径厚度尺寸取约束取原条件R取
次设计中采R50～60mm
(4)锥面工作长度b
（61）
设计中考虑降低成取相b取5mm
(5)步环径厚度
摩擦锥面均半径样步环径厚度受机构布置限制包括变速器中心距相关零件特锥面均半径布置限制宜取厚步环径厚度必须保证步环足够强度
轿车步环厚度货车应选锻件精密锻造工艺加工制成提高材料屈服强度疲劳寿命货车步环压铸加工段造时选锰黄铜等材料变速器高强度高耐磨性钢配合摩擦副钢质球墨铸铁步环锥面喷镀层钼（厚约03～05mm）摩擦数钢铜合金摩擦副范围耐磨性强度显著提高步环铜环基体锥空表面喷厚007～012mm钼制成喷钼环寿命铜环2～3倍钢质基体步环仅节约铜提高步环强度
设计中步器径宽度取105mm
(6)锁止角
锁止角选取正确保证换档两部分间角速度差达零值进行换档影响锁止角选取素摩擦数擦锥面均半径R锁止面均半径锥面半锥角已结构锁止角26°～46°范围变化
次设计锁止角取
(7)步时间t
步器工作时连接两部分达步时间越短越步器结构尺寸转动惯量步时间影响外变速器输入轴输出轴角速度差作步器摩擦锥面轴力均步时间影响轴力步时间减少轴力作变速杆手柄力关车型求作手柄力相步时间车型关计算时属范围选取：轿车变速器高档取015～030s低档取050～080s货车变速器高档取030～080s低档取100～150s
62变速器操机构
621操机构功
变速器操机构功保证档齿轮啮合套步器移动规定距离获求档位允许时挂两档位
622操机构设计求
(1)锁止装置包括锁互锁倒档锁
a互锁装置保证移动某变速叉轴时变速杆叉轴互锁止互锁装置结构种：互锁销式摆动锁块式转动锁止式三锁销式次设计中互锁装置选择第种结构型式图64示
b锁装置作定位防止汽车振动轴力作致脱档保证啮合齿轮全齿长进行啮合驾驶员换档感觉定位作通锁装置中弹簧钢球（锁销）推入叉轴凹臼中实现变速叉轴凹臼间距挂档齿轮移动距离决定结构型式图64示
c汽车行驶程中防止误挂倒档致造成安全事损坏传动系操机构中设倒档锁倒档安全装置倒档锁驾驶员挂倒档时驾驶员明显手感起提醒作防止误挂倒档结构见总装配图
图64 变速器锁互锁结构
1锁钢球 2锁弹簧 3变速器盖4互锁钢球 5互锁销 6拨叉轴
(2)换档动作轻便省力减轻驾驶员疲劳强度
(3)应驾驶员必手感
623变速器换档位置
设计操机构首先确定换档位置换档位置确定换档方便考虑应该注意三点：
(1)换档次序排列
(2)常档放中间位置档放两边
(3)避免误挂倒档倒档安排边位置时1档组成排
根三点次设计变速器换档位置图65示：
图65 换档位置图
63章结
章步器基结构工作原理进行分析步器参数进行选取包括螺纹槽数宽度半锥角摩擦锥面均半径等解变速器操机构作设计求必须包括锁互锁倒档锁样保证操作省力容易挂错档位
第7章 轴承选寿命计算
71 第轴轴承选计算
1初选轴承型号
工作条件轴颈直径初选轴轴承型号6306转速5000rmin
2计算轴承量动载荷
（71）
（72）
（73）
查表e038查表X056Y115
量动载荷：
48317N （74）
3计算轴承基额定寿命
轴承基额定寿命：（寿命指数球轴承3）
（75）
带入201873h20000h满足求
72第二轴轴承选计算
1初选轴承型号
工作条件轴颈直径初选二轴轴承型号6305转速5000rmin
2计算轴承量动载荷
（76）
（77）
（78）
查表e044查表X056Y100
量动载荷：
86285N （79）
3计算轴承基额定寿命
轴承基额定寿命：
（710）
带入213408h20000h满足求
73章结
章变速器轴承进行选校核轴承变速器重组成部分保证齿轮轴旋转运动章轴承寿命进行校核变速器转速非常高需根变速器整体布置进行合适轴承选择保证整体寿命
第8章
81 CATIA软件简介
CATIA V5软件法国Dassault公司1975年开发套完整3D CADCAMCAE 体化软件容涵盖产品概念设计工业设计三维建模分析计算动态模拟仿真工程图生成生产加工成产品全程中包括量电缆道布线种模具设计分析机交换等实模块CATIA V5 保证企业部设计部门间协设计功提供企业整集团设计流程端端解决方案CATIA V5 量应航空航天汽车摩托车行业机械电子家电3C产业NC加工等领域
功强完美CATIA V5 已成三维CADCAM领域面旗帜争相遵准特航空航天汽车摩托车领域CATIA V5 仅户提供详细解决方案具先进开发性集成性灵活性功：三维图形设计二维工程蓝图绘制复杂空间曲面设计验证三维计算机辅助加工制造加工轨迹模拟机构设计运动分析标准零件理
82变速器软件设计
821齿轮建模
（1）选择文件à新建命令类型列表中选择Partà确定à启混合设计à确定
（2）进入创成式外形设计àf(x)进入公示编辑界面图81
图81
然齿轮进行参数化设计编辑公示图82
图82
（3）选择XY面à草绘à创建4圆编辑公示半径分d2da2db2df2图83
图83
（4）单击规à新建规Xà编辑公式
XXdb2*cos(PI2*t)+db2*PI2*t*sin(PI2*t)à
重复述步骤编辑公式
Ydb2*sin(PI2*t)db2*PI2*t*cos(PI2*t)à创建点图84
图84 图85 图86
à样条曲线链接点à提取分度圆à相交à面参考相交点Z轴à面角度法线（角度360deg(4*z)）à提取分度圆à外插延伸à称图85
（5）提取齿顶圆à进入XY面à投影齿顶圆齿根圆样条曲线à倒角pfà投影面图86à旋转（角度asin(2*b*tan(beta)d)）à截面曲面à厚曲面à阵列图87
图87
822变速器装配
先选择输入轴作固定件然相合约束偏移约束接触约束等命令齿轮步器等零部件进行装配约束装配完 成状态图88
图88
823变速器仿真
（1）新建机构1à创建齿轮接头图89à创建刚性固连零件连起图810
（2）创建机构2à创建柱块接头图811à步骤创建2档位接头图812
图89
图811
图810 图812
83章结：
通变速器三维软件建模更深刻学结构组装时该软件更加熟练特模块中装配仿真工作基础
结
次设计汽车变速器部分变速器车辆缺部分中机械式变速箱设计发展天技术已成熟踏出校门学生说中设计理念值探讨学
次设计变速箱说特点：扭矩变化范围满足工况求结构简单易生产维修价格低廉采步器挂挡变速器挂挡稳噪声降低轮齿易损坏设计中采五档手动变速器通较变速器传动变化范围满足汽车工况求达济性动力性求变速器挂档时结合套然增加成汽车变速器操舒适度增加齿轮传动更稳着实性济性原部件设计求采较开放标准安全系数高点次设计理想处工作学中会继续学研究变速器技术求设计更加合理济
紧张忙碌毕业设计已接尾声次设计学学次综合检验更次综合学程毕业设计仅学巩固专业课知识解少相关专业知识力提高时锻炼协作精神踏入社会工作良基础
致 谢
转眼间学四年快结束作学生活环节—毕业设计12周紧张准备接尾声次毕业设计中巩固前学知识中学新东西尤汽车设计汽车理两门课程里四年里巨帮助老师学表示衷心感谢正帮忙圆满完成四年学业毕业设计
次设计程中指导老师XX直关注着步进展意见建议时提出严格求利完成毕业设计务李老师指导分开表示感谢
外遇技术困难时候车辆工程专业老师帮助需帮助时候非常耐心解答里表示衷心感谢
参考文献
[1] 刘惟信 汽车设计[M]北京清华学出版社2001
[2] 郭新华汽车构造[M]北京高等教育出版社2004
[3] 余志生汽车理[M]北京：机械工业出版社2010
[4] 学迅邓亚东汽车设计[M]北京：民交通出版社2008
[5] 王黎钦陈铁鸣机械设计[M]哈尔滨：哈尔滨工业学出版社2008
[6] 孙恒陈作模葛文杰机械原理[M] 北京高等教育出版社2006
[7] 张景田季雅娟丁建梅画法机械制图[M]哈尔滨：哈尔滨工业学出版社2005
[8] 刘品李哲机械精度设计检测基础[M]哈尔滨：哈尔滨工业学出版社2009
[9] 王宝玺贾庆祥汽车制造工艺学[M] 北京：机械工业出版社2007
[10] 江洪李仲兴陆利锋CATIA基础教程[M] 北京：机械工业出版社2005
[11] 施建胡建杰CATIA造型设计项目案例解析 北京清华学出版社2010
[12] HansHermann Braess Ulrich Seiffert Handbook of Automotive Engineering SAE International 2004
[13] James DHalderman Chase DMitchell Automotive technology principle diagnosis and service Pearson Education lnc 2004
短期课程
动变速器
查尔斯奥法里
现代动变速器迄止天汽车复杂机械部件动变速器包括机械系统液压系统电气系统计算机控制完美结合起没什问题文帮助您解里面技术奇迹修复失败时候什概念
文分五部分：
•什传输破简单传输目什
•传动部件描述系统般原理简单说帮助您解动变速器厂
•发现问题变更糟前表示寻求防止问题变成
•维护谈预防性维护应该知道
•传输修理修理通常轻微调整传输完成检修类型
________________________________________
传输什？
变速器连接面引擎发动机动力传递驱动轮装置汽车发动机处佳状态定转速运行（转分钟）范围传输工作确保动力传递驱动轮时保持该范围发动机通齿轮组合第轮发动机关系驱动轮速度更快高速运转发动机蛇王汽车会超70英里前进档变速器中立立场断开发动机驱动轮反驱动轮相反方转回停车位位置闩锁机制（门锁舌锁定）插入输出轴槽锁驱动轮阻止转动防止汽车移动
两种基类型动变速器车辆否轮驱动前轮驱动
轮驱动汽车变速器通常安装发动机端位底盘中心油门踏板位置驱动轴连接传输位桥终驱动动力传递轮功率流系统简单直接发动机通液力变矩器然通变速器传动轴直传动分送两车轮
传输什？
变速器连接面引擎发动机动力传递驱动轮装置汽车发动机处佳状态定转速运行（转分钟）范围传输工作确保动力传递驱动轮时保持该范围发动机通齿轮组合第轮发动机关系驱动轮速度更快高速运转发动机蛇王汽车会超70英里前进档变速器中立立场断开发动机驱动轮反驱动轮相反方转回停车位位置闩锁机制（门锁舌锁定）插入输出轴槽锁驱动轮阻止转动防止汽车移动
两种基类型动变速器车辆否轮驱动前轮驱动
轮驱动汽车变速器通常安装发动机端位底盘中心油门踏板位置驱动轴连接传输位桥终驱动动力传递轮功率流系统简单直接发动机通液力变矩器然通变速器传动轴直传动分送两车轮
前轮驱动汽车变速器通常结合形成谓终驱动桥前轮驱动汽车发动机通常安装车侧跨桥塞面汽车部发动机侧前车轴直接连接驱动桥提供电力前轮例子中功率流发动机通液力变矩器型链条动力通180度转传动侧发动机里权力传输驱动器分裂通传动轴传递两前轮
安排包括前轮驱动车辆发动机安装前横着系统四轮驱动两种系统目前受欢迎太常见驱布置变速器直接安装驱动器部传动轴扭矩转换器然安装发动机连接系统新出厂发现衡重量均匀前轮轮间改进性处理轮驱动系统安装切发动机传输终驱动器面发动机置布置流行保时捷
________________________________________
传动部件
现代动变速器设计巧妙机械交响乐团起工作许部件系统液压电气技术年发展许机械倾认种艺术形式尝试简单通解释描述系统复杂组件您需视化操作
组成动变速器部件包括：
•行星齿轮组提供前进档倒档机械系统
•液压系统采种特殊传动液泵压力通阀体控制离合器带控制行星齿轮组
•密封件垫片机油里应该防止漏油
•液力变矩器离合器允许车辆齿轮停止发动机运行
•调节器节流阀电缆监测速度节气门位置确定时移
•新型车辆换挡点计算机引导电螺线改变油流适组件正确时控制
行星齿轮组
前轮驱动汽车变速器通常结合形成谓终驱动桥前轮驱动汽车发动机通常安装车侧跨桥塞面汽车部发动机侧前车轴直接连接驱动桥提供电力前轮例子中功率流发动机通液力变矩器型链条动力通180度转传动侧发动机里权力传输驱动器分裂通传动轴传递两前轮
安排包括前轮驱动车辆发动机安装前横着系统四轮驱动两种系统目前受欢迎太常见驱布置变速器直接安装驱动器部传动轴扭矩转换器然安装发动机连接系统新出厂发现衡重量均匀前轮轮间改进性处理轮驱动系统安装切发动机传输终驱动器面发动机置布置流行保时捷
________________________________________
传动部件
现代动变速器设计巧妙机械交响乐团起工作许部件系统液压电气技术年发展许机械倾认种艺术形式尝试简单通解释描述系统复杂组件您需视化操作
组成动变速器部件包括：
•行星齿轮组提供前进档倒档机械系统
•液压系统采种特殊传动液泵压力通阀体控制离合器带控制行星齿轮组
•密封件垫片机油里应该防止漏油
•液力变矩器离合器允许车辆齿轮停止发动机运行
•调节器节流阀电缆监测速度节气门位置确定时移
•新型车辆换挡点计算机引导电螺线改变油流适组件正确时控制
行星齿轮组
动变速器包括许齿轮组合手动变速箱齿轮轴滑动移动换挡杆位置事种齿轮求提供正确传动然动变速器中齿轮移动保持啮合通行星齿轮组完成
基行星齿轮装置太阳轮齿圈两两行星齿轮剩余常啮合行星齿轮连接彼通载体齿轮旋转轴称齿轮附着载体
种方式该系统应例子连接齿圈发动机输入轴连接行星架输出轴锁定太阳齿轮动种情况转动齿圈行星走着太阳轮（
固定）导致行星架转动输出轴方输入轴速度较慢速度导致齿轮减速（类似汽车第齿轮）
果解开太阳齿轮锁两元素导致三素相速度输出轴速度作输入轴转率辆汽车第三高齿轮种方式行星齿轮组行星架固定移动然运权力环带动太阳轮反倒档齿轮
右边图显示述简单系统实际传输输入轴连接环形齿轮（蓝色）输出轴行星架（绿色）单离合器
单离合器（称斜撑离合器）种装置允许组件环形齿轮转方种效果样行车踏板车轮前蹬踏旋时蹬
单离合器第齿轮时移相器驱动位置开始加速停止开始第齿轮传动没注意果释放气体然第轮会发生什？汽车继续滑行仿佛中性现切换低速齿轮代开车停止加油种情况会感觉发动机放慢标准移动车驱动单离合器低离合器者带
乐队
种带种摩擦材料表面钢表带该带端固定变速器壳体端连接伺服适时间液压油送伺服压力收紧带滚筒停止滚筒转动
液力变矩器
动变速器液力变矩器标准换档车辆离合器方存发动机继续运行车辆停止时液力变矩器原理扇插入吹风扇果抓住拔掉风扇叶片举行放手会开始加速直接风扇转速动力液力变矩器空气油传动液更精确
液力变矩器种形装置炸圈饼（1015直径）安装发动机变速器间三部元素起发射功率传输变矩器三素泵涡轮定子泵直接安装转换器壳体次直接连接发动机曲轴发动机转速转涡轮机房屋直接连接传输提供动力驱动车辆输入轴定子安装单离合器旋转方三种元素鳍安装正直接通变矩器油流
发动机运转时传动液进入泵部分离心力外推直转动涡轮流体断循环运动回定子涡轮中心果涡轮速度低泵液体会定子定子翅片推单离合器前接触阻止旋转停止定子液体叶轮重新泵帮助角度提供扭矩增加涡轮速度赶泵流体开始攻击静子叶片造成定子方转动泵涡轮背面着速度增加三素开始转约相速度
年代提高燃油济性变矩器配备锁止离合器（未显示）锁定涡轮泵车辆速度达约45 50英里锁定计算机控制通常会进行非第三第四齿轮传动
液压系统
液压系统复杂通道发送传输流体压力传动液力变矩器部件迷宫左边图3速动60年代简单新系统更复杂结合计算机电气元件传动液项途包括：变速控制般润滑冷变速器发动机采油润滑传输功方面压力赖断提供液体类循环系统（液体甚红色）甚分钟操作时缺乏压力害传输生活甚致命保持变速器正常工作温度流体部分通两钢专室THA派
A Short Course on
Automatic Transmissions
by Charles Ofria
The modern automatic transmission is by far the most complicated mechanical component in today＇s automobile Automatic transmissions contain mechanical systems hydraulic systems electrical systems and computer controls all working together in perfect harmony which goes virtually unnoticed until there is a problem This article will help you understand the concepts behind what goes on inside these technological marvels and what goes into repairing them when they fail
This article is broken down into five sections
· What is a transmission breaks down in the simplest terms what the purpose of a transmission is
· Transmission Components describes the general principals behind each system in simple terms to help you understand how an automatic transmission works
· Spotting problems before they get worse shows what to look for to prevent a minor problem from becoming major
· Maintenance talks about preventative maintenance that everyone should know about
· Transmission repairs describes the types of repairs that are typically performed on transmissions from minor adjustments to complete overhauls
What is a transmission
The transmission is a device that is connected to the back of the engine and sends the power from the engine to the drive wheels An automobile engine runs at its best at a certain RPM (Revolutions Per Minute) range and it is the transmission＇s job to make sure that the power is delivered to the wheels while keeping the engine within that range It does this through various gear combinations In first gear the engine turns much faster in relation to the drive wheels while in high gear the engine is loafing even though the car may be going in excess of 70 MPH In addition to the various forward gears a transmission also has a neutral position which disconnects the engine from the drive wheels and reverse which causes the drive wheels to turn in the opposite direction allowing you to back up Finally there is the Park position In this position a latch mechanism (not unlike a deadbolt lock on a door) is inserted into a slot in the output shaft to lock the drive wheels and keep them from turning thereby preventing the vehicle from rolling
There are two basic types of automatic transmissions based on whether the vehicle is rear wheel drive or front wheel drive
On a rear wheel drive car the transmission is usually mounted to the back of the engine and is located under the hump in the center of the floorboard alongside the gas pedal position A drive shaft connects the rear of the transmission to the final drive which is located in the rear axle and is used to send power to the rear wheels Power flow on this system is simple and straight forward going from the engine through the torque converter then through the transmission and drive shaft until it reaches the final drive where it is split and sent to the two rear wheels
On a front wheel drive car the transmission is usually combined with the final drive to form what is called a transaxle The engine on a front wheel drive car is usually mounted sideways in the car with the transaxle tucked under it on the side of the engine facing the rear of the car Front axles are connected directly to the transaxle and provide power to the front wheels In this example power flows from the engine through the torque converter to a large chain that sends the power through a 180 degree turn to the transmission that is along side the engine From there the power is routed through the transmission to the final drive where it is split and sent to the two front wheels through the drive axles
There are a number of other arrangements including front drive vehicles where the engine is mounted front to back instead of sideways and there are other systems that drive all four wheels but the two systems described here are by far the most popular A much less popular rear drive arrangement has the transmission mounted directly to the final drive at the rear and is connected by a drive shaft to the torque converter which is still mounted on the engine This system is found on the new Corvette and is used in order to balance the weight evenly between the front and rear wheels for improved performance and handling Another rear drive system mounts everything the engine transmission and final drive in the rear This rear engine arrangement is popular on the Porsche
Transmission Components
The modern automatic transmission consists of many components and systems that are designed to work together in a symphony of clever mechanical hydraulic and electrical technology that has evolved over the years into what many mechanically inclined individuals consider to be an art form We try to use simple generic explanations where possible to describe these systems but due to the complexity of some of these components you may have to use some mental gymnastics to visualize their operation
The main components that make up an automatic transmission include
· Planetary Gear Sets which are the mechanical systems that provides the various forward gear ratios as well as reverse
· The Hydraulic System which uses a special transmission fluid sent under pressure by an Oil Pump through the Valve Body to control the Clutches and the Bands in order to control the planetary gear sets
· Seals and Gaskets are used to keep the oil where it is supposed to be and prevent it from leaking out
· The Torque Converter which acts like a clutch to allow the vehicle to come to a stop in gear while the engine is still running
· The Governor and the Modulator or Throttle Cable that monitor speed and throttle position in order to determine when to shift
· On newer vehicles shift points are controlled by Computer which directs electrical solenoids to shift oil flow to the appropriate component at the right instant
Planetary Gear Sets
Automatic transmissions contain many gears in various combinations In a manual transmission gears slide along shafts as you move the shift lever from one position to another engaging various sized gears as required in order to provide the correct gear ratio In an automatic transmission however the gears are never physically moved and are always engaged to the same gears This is accomplished through the use of planetary gear sets
The basic planetary gear set consists of a sun gear a ring gear and two or more planet gears all remaining in constant mesh The planet gears are connected to each other through a common carrier which allows the gears to spin on shafts called pinions which are attached to the carrier
One example of a way that this system can be used is by connecting the ring gear to the input shaft coming from the engine connecting the planet carrier to the output shaft and locking the sun gear so that it can＇t move In this scenario when we turn the ring gear the planets will walk along the sun gear (which is held stationary) causing the planet carrier to turn the output shaft in the same direction as the input shaft but at a slower speed causing gear reduction (similar to a car in first gear)
If we unlock the sun gear and lock any two elements together this will cause all three elements to turn at the same speed so that the output shaft will turn at the same rate of speed as the input shaft This is like a car that is in third or high gear Another way that we can use a Planetary gear set is by locking the planet carrier from moving then applying power to the ring gear which will cause the sun gear to turn in the opposite direction giving us reverse gear
The illustration on the right shows how the simple system described above would look in an actual transmission The input shaft is connected to the ring gear (Blue) The Output shaft is connected to the planet carrier (Green) which is also connected to a Multidisk clutch pack The sun gear is connected to a drum (yellow) which is also connected to the other half of the clutch pack Surrounding the outside of the drum is a band (red) that can be tightened around the drum when required to prevent the drum with the attached sun gear from turning
The clutch pack is used in this instance to lock the planet carrier with the sun gear forcing both to turn at the same speed If both the clutch pack and the band were released the system would be in neutral Turning the input shaft would turn the planet gears against the sun gear but since nothing is holding the sun gear it will just spin free and have no effect on the output shaft To place the unit in first gear the band is applied to hold the sun gear from moving To shift from first to high gear the band is released and the clutch is applied causing the output shaft to turn at the same speed as the input shaft
Many more combinations are possible using two or more planetary sets connected in various ways to provide the different forward speeds and reverse that are found in modern automatic transmissions
Some of the clever gear arrangements found in four and now five six and even seven and eightspeed automatics are complex enough to make a technically astute lay person＇s head spin trying to understand the flow of power through the transmission as it shifts from first gear through top gear while the vehicle accelerates to highway speed On modern vehicles (mid ＇80s to the present) the vehicle＇s computer monitors and controls these shifts so that they are almost imperceptible
Clutch Packs
A clutch pack consists of alternating disks that fit inside a clutch drum Half of the disks are steel and have splines that fit into groves on the inside of the drum The other half have a friction material bonded to their surface and have splines on the inside edge that fit groves on the outer surface of the adjoining hub There is a piston inside the drum that is activated by oil pressure at the appropriate time to squeeze the clutch pack together so that the two components become locked and turn as one
OneWay Clutch
A oneway clutch (also known as a sprag clutch) is a device that will allow a component such as ring gear to turn freely in one direction but not in the other This effect is just like that of a bicycle where the pedals will turn the wheel when pedaling forward but will spin free when pedaling backward
A common place where a oneway clutch is used is in first gear when the shifter is in the drive position When you begin to accelerate from a stop the transmission starts out in first gear But have you ever noticed what happens if you release the gas while it is still in first gear The vehicle continues to coast as if you were in neutral Now shift into Low gear instead of Drive When you let go of the gas in this case you will feel the engine slow you down just like a standard shift car The reason for this is that in Drive a oneway clutch is used whereas in Low a clutch pack or a band is used
Bands
A band is a steel strap with friction material bonded to the inside surface One end of the band is anchored against the transmission case while the other end is connected to a servo At the appropriate time hydraulic oil is sent to the servo under pressure to tighten the band around the drum to stop the drum from turning
Torque Converter
On automatic transmissions the torque converter takes the place of the clutch found on standard shift vehicles It is there to allow the engine to continue running when the vehicle comes to a stop The principle behind a torque converter is like taking a fan that is plugged into the wall and blowing air into another fan which is unplugged If you grab the blade on the unplugged fan you are able to hold it from turning but as soon as you let go it will begin to speed up until it comes close to the speed of the powered fan The difference with a torque converter is that instead of using air it uses oil or transmission fluid to be more precise
A torque converter is a large doughnut shaped device (10 to 15 in diameter) that is mounted between the engine and the transmission It consists of three internal elements that work together to transmit power to the transmission The three elements of the torque converter are the Pump the Turbine and the Stator The pump is mounted directly to the converter housing which in turn is bolted directly to the engine＇s crankshaft and turns at engine speed The turbine is inside the housing and is connected directly to the input shaft of the transmission providing power to move the vehicle The stator is mounted to a oneway clutch so that it can spin freely in one direction but not in the other Each of the three elements have fins mounted in them to precisely direct the flow of oil through the converter
With the engine running transmission fluid is pulled into the pump section and is pushed outward by centrifugal force until it reaches the turbine section which starts it turning The fluid continues in a circular motion back towards the center of the turbine where it enters the stator If the turbine is moving considerably slower than the pump the fluid will make contact with the front of the stator fins which push the stator into the one way clutch and prevent it from turning With the stator stopped the fluid is directed by the stator fins to reenter the pump at a helping angle providing a torque increase As the speed of the turbine catches up with the pump the fluid starts hitting the stator blades on the backside causing the stator to turn in the same direction as the pump and turbine As the speed increases all three elements begin to turn at approximately the same speed
Since the ＇80s in order to improve fuel economy torque converters have been equipped with a lockup clutch (not shown) which locks the turbine to the pump as the vehicle speed reaches approximately 45 50 MPH This lockup is controlled by computer and usually won＇t engage unless the transmission is in 3rd or 4th gear
Hydraulic System
The Hydraulic system is a complex maze of passages and tubes that sends transmission fluid under pressure to all parts of the transmission and torque converter The diagram at left is a simple one from a 3speed automatic from the ＇60s The newer systems are much more complex and are combined with computerized electrical components Transmission fluid serves a number of purposes including shift control general lubrication and transmission cooling Unlike the engine which uses oil primarily for lubrication every aspect of a transmission＇s functions is dependant on a constant supply of fluid under pressure This is not unlike the human circulatory system (the fluid is even red) where even a few minutes of operation when there is a lack of pressure can be harmful or even fatal to the life of the transmission In order to keep the transmission at normal operating temperature a portion of the fluid is sent through one of two steel tubes to a special chamber that is submerged in antifreeze in the radiator Fluid passing through this chamber is cooled and then returned to the transmission through the other steel tube A typical transmission has an average of ten quarts of fluid between the transmission torque converter and cooler tank In fact most of the components of a transmission are constantly submerged in fluid including the clutch packs and bands The friction surfaces on these parts are designed to operate properly only when they are submerged in oil
Oil Pump
The transmission oil pump (not to be confused with the pump element inside the torque converter) is responsible for producing all the oil pressure that is required in the transmission The oil pump is mounted to the front of the transmission case and is directly connected to a flange on the torque converter housing Since the torque converter housing is directly connected to the engine crankshaft the pump will produce pressure whenever the engine is running as long as there is a sufficient amount of transmission fluid available The oil enters the pump through a filter that is located at the bottom of the transmission oil pan and travels up a pickup tube directly to the oil pump The oil is then sent under pressure to the pressure regulator the valve body and the rest of the components as required
Valve Body
The valve body is the control center of the automatic transmission It contains a maze of channels and passages that direct hydraulic fluid to the numerous valves which then activate the appropriate clutch pack or band servo to smoothly shift to the appropriate gear for each driving situation Each of the many valves in the valve body has a specific purpose and is named for that function For example the 23 shift valve activates the 2nd gear to 3rd gear upshift or the 32 shift timing valve which determines when a downshift should occur
The most important valve and the one that you have direct control over is the manual valve The manual valve is directly connected to the gear shift handle and covers and uncovers various passages depending on what position the gear shift is placed in When you place the gear shift in Drive for instance the manual valve directs fluid to the clutch pack(s) that activates 1st gear It also sets up to monitor vehicle speed and throttle position so that it can determine the optimal time and the force for the 1 2 shift On computer controlled transmissions you will also have electrical solenoids that are mounted in the valve body to direct fluid to the appropriate clutch packs or bands under computer control to more precisely control shift points
Computer Controls
The computer uses sensors on the engine and transmission to detect such things as throttle position vehicle speed engine speed engine load brake pedal position etc to control exact shift points as well as how soft or firm the shift should be Once the computer receives this information it then sends signals to a solenoid pack inside the transmission The solenoid pack contains several electrically controlled solenoids that redirect the fluid to the appropriate clutch pack or servo in order to control shifting Computerized transmissions even learn your driving style and constantly adapt to it so that every shift is timed precisely when you would need it
Because of computer controls sports models are coming out with the ability to take manual control of the transmission as though it were a stick shift allowing the driver to select gears manually This is accomplished on some cars by passing the shift lever through a special gate then tapping it in one direction or the other in order to upshift or downshift at will The computer monitors this activity to make sure that the driver does not select a gear that could over speed the engine and damage it
Another advantage to these smart transmissions is that they have a self diagnostic mode which can detect a problem early on and warn you with an indicator light on the dash A technician can then plug test equipment in and retrieve a list of trouble codes that will help pinpoint where the problem is
Governor Vacuum Modulator Throttle Cable
These three components are important in the noncomputerized transmissions They provide the inputs that tell the transmission when to shift The Governor is connected to the output shaft and regulates hydraulic pressure based on vehicle speed It accomplishes this using centrifugal force to spin a pair of hinged weights against pullback springs As the weights pull further out against the springs more oil pressure is allowed past the governor to act on the shift valves that are in the valve body which then signal the appropriate shifts
Of course vehicle speed is not the only thing that controls when a transmission should shift the load that the engine is under is also important The more loads you place on the engine the longer the transmission will hold a gear before shifting to the next one
There are two types of devices that serve the purpose of monitoring the engine load the Throttle Cable and the Vacuum Modulator A transmission will use one or the other but generally not both of these devices Each works in a different way to monitor engine load
The Throttle Cable simply monitors the position of the gas pedal through a cable that runs from the gas pedal to the throttle valve in the valve body
The Vacuum Modulator monitors engine vacuum by a rubber vacuum hose which is connected to the engine Engine vacuum reacts very accurately to engine load with high vacuum produced when the engine is under light load and diminishing down to zero vacuums when the engine is under a heavy load The modulator is attached to the outside of the transmission case and has a shaft which passes through the case and attaches to the throttle valve in the valve body When an engine is under a light load or no load high vacuum acts on the modulator which moves the throttle valve in one direction to allow the transmission to shift early and soft As the engine load increases vacuum is diminished which moves the valve in the other direction causing the transmission to shift later and more firmly
Seals and Gaskets
An automatic transmission has many seals and gaskets to control the flow of hydraulic fluid and to keep it from leaking out There are two main external seals the front seal and the rear seal The front seal seals the point where the torque converter mounts to the transmission case This seal allows fluid to freely move from the converter to the transmission but keeps the fluid from leaking out The rear seal keeps fluid from leaking past the output shaft
A seal is usually made of rubber (similar to the rubber in a windshield wiper blade) and is used to keep oil from leaking past a moving part such as a spinning shaft In some cases the rubber is assisted by a spring that holds the rubber in close contact with the spinning shaft
A gasket is a type of seal used to seal two stationary parts that are fastened together Some common gasket materials are paper cork rubber silicone and soft metal
Aside from the main seals there are also a number of other seals and gaskets that vary from transmission to transmission A common example is the rubber Oring that seals the shaft for the shift control lever This is the shaft that you move when you manipulate the gear shifter Another example that is common to most transmissions is the oil pan gasket In fact seals are required anywhere that a device needs to pass through the transmission case with each one being a potential source for leaks
文档香网(httpswwwxiangdangnet)户传
《香当网》用户分享的内容，不代表《香当网》观点或立场，请自行判断内容的真实性和可靠性！
该内容是文档的文本内容，更好的格式请下载文档