壳体设计规范

1、 introduction 介绍 function overview 功能概述 gearbox types 壳体类型 design guidelines 设计指南 gears & shafts, bearings, fasteners, flanges, flange sealing, ribs, joints, radii, wall thickness, corrosion, surface treatment, nvh 齿轮、轴，轴承、紧固件、凸 缘、凸缘密封、筋、过渡连接，倒圆 角，壁厚，腐蚀，表面处理、噪音 materials options 材料选择 material weight

2、 材料重量 suitable casting options 铸造类 型 sand casting 砂型铸造 gravity die重力铸造 die casting压铸 low pressure低压 high pressure高压 casting tolerance comparison铸造公差比较 material comparison材料比较 heat treatment - comparison热处理 - 比较 material machinability材料可加工性能 typical transmission case materials 传统变速箱壳体材料 pro/e casing

3、modelling process pro / e的 建模过程 typical design process典型的设计过程 casing design - summary外壳设计 - 总结 case study mg vs aluminium 案例分析 - 镁合金与铝合金比较 the aim of this guide is to help the designer to make an informed choice when designing a transmission case or casings. the choices taken will depend on many fac

4、tors such as: 本指南的目的是帮助设计人员在设计变速箱外壳时，作出正确的选择。需要考虑的因素如下： time时间 available time to design and or manufacture 设计和制造所用时间 cost成本 cost targets (of design, materials,manufacturing and processes) 成本目标（设计，材料，制造） number of units 组件数量 small, medium of large volumes 小件，中件，大件 function功能 structural, non structura

5、l, loaded vs non- loaded 结构性或者非结构性功能，承载或者非承载结构 size尺寸 overall size of transmission, castability, machinability, 变速器外形尺寸，铸造性能，机械加工 性能 complexity 复杂性 influenced by size and function compromised by castability / machinability 受尺寸、功能、铸造性能/可加工性的影 响 material材料 iron, aluminum or magnesium alloys 铁，铝合金或镁合金

6、environment 环境 external regime, package as well as recyclability of materials 外部政策，包装以及材料可回收性 duty 工况 life, duty cycle, load regime, torque and power 路谱，负载，扭矩和动力 weight重量 target vehicle weight, transmission target weight see materials 目标车辆的重量，变速箱的目标重量-由变速箱材料决定 vehicle type车辆类型 transverse, longitudin

7、al, fwd, rwd, 2wd,4wd 横置，纵置，前轮驱动，后轮驱动，两轮驱动， 四轮驱动 to provide a suitable housing so that speed and torque can be transmitted from the input via shafts, gears or pulleys to the output. these speeds and torques can be 一个结构合理的壳体，可以使速度和扭矩从发动机经过 输入轴，齿轮或滑套传到输出轴。使速度和扭矩达到如下变化： continuous 连续 stepped 阶梯 constan

8、tly changing 不断变化的 speeds and torques impart loads as a result of the gears, shaft and differentials. the housing react these loads and forces 齿轮，轴和差速器的速度和转矩最终以力的形式作用到 壳体 provide an oil reservoir for cooling and lubrication 为变速箱冷却和润滑提供油路系统 in addition mount or support other sub systems such as为其他子系统

9、 提供安装支撑，如下： drive clutches 驱动离合器 csc engine starter motors 发动机起动马达 manual shifter systems 手动换档系统 shift mechanisms, rails & forks, cable brackets 换挡机构、手柄、拨叉、拉线支架 hydraulic shifter systems 液压换挡系统 automated manual shift mechanisms 自动换挡系统 wet clutches powershift etc pumps,accumulators, coolers, filters

10、etc 湿式离合器 - 动力换档原件，如泵，蓄能器，冷却器，过滤 器等 park brakes 驻车制动 depending on the type of loads and installation casings can be divided into two types: 根据载荷的不同，可将壳体分为两类： non structural the loads the casing sees are from the shafts and gears only with the casing hanging off the engine and the vehicle side member

11、 非结构性壳体-齿轮和轴作用到壳体上的作用 力最后作用到发动机和车辆侧梁 private vehicles 乘用车 commercial vehicles 商用车 structural 结构性壳体 tractor chassis- transaxles 牵引 车底盘-驱动桥 the transmission case is an integral part of the chassis. 变速箱是底盘的一个组成部 分 motor-sport applications 赛车的应用 transaxle designs vehicle loads going through the casing s

12、uch as tractor transaxle suspension hard points located on them. 驱动桥设计 - 车辆荷载通过变 速箱壳体悬置部位传递到它们 non structural motor-sport transaxle tractor transaxle牵引车驱动桥 these are the main components for transferring speed and torque in a transmission 在变速箱结构中，这些是用于传递速度和扭矩主要组件。 as a result they impart the followin

13、g type of loads on the casing 齿轮和轴从下面几个方面影响作用到壳体上的作用力： separating loads are effectively trying to push the each shaft and gear apart. 分离载荷（径向力）有效地将每个轴和齿轮推开。 tangential loads act normal to the base circle are a result of the gears reacting against each other. 垂直于基圆的切向力是齿轮之间相互作用的结果 axial loads act alo

14、ng the rotating axis of the gear and shaft. 轴向载荷沿齿轮和轴的轴向传递。 helical gears over spur gears will result in having to consider axial load effects.the larger the helix angle the larger the load. other gear forms that impart axial loads include bevel and hypoid gearing 斜齿轮与直齿轮相比，必须考虑轴向载荷的影响。螺旋角越大轴向载荷越大。锥

15、齿轮和 准双曲面齿轮也必须考虑轴线载荷的影响 the bearings are the elements that actually interact with the casing. it is here that the gearing loads pass through the rolling elements into the casing. the size and type are very much dependant on the loads anticipated as well as the layout of the rotating parts within it.

16、轴承是直接与外壳相互作用的元件。齿轮力最终通过轴承 内部的旋转件传递到外壳。轴承尺寸和类型的选择依赖于受力大小以 及内部旋转件的布局。 deep groove ball - 深沟球轴承 cylindrical roller圆柱滚子轴承 taper roller圆锥滚子轴承 the seating / mounting of the bearings in the casings needs careful consideration 壳体轴承的安装需要进行充分的考虑 bore bore 轴承孔 this will ensure that the bearing retains it shape

17、 when loaded 这将确保轴承在受力时形状保持不变。 needs to be manufactured to tight tolerances to ensure the bore is round and concentric to the shaft axis. 需要严格按照公差加工，以确保该孔的圆度并且于轴的轴线同心。 the amount of interference / clearance depends on the type of bearing and load 轴承与轴承孔之间的配合间隙取决于轴承类型和轴承力 typical transmission applica

18、tions the outer race is held in the casing with a interference fit. 传统的变速箱应用，轴承外圈与壳体采用过盈配合 for bearings that require some adjustment during build a transition fit can be employed. 一些需要调整的轴承，一般采用过度配合。 general recommendations 一般建议 aluminum - 0.001mm of interference per mm of diameter. 铝合金壳-直径方向每毫米过盈量为

19、0.001mm magnesium - 0.0015mm of interference per mm of diameter. 镁合金壳-直径方向每毫米过盈量为0.0015mm abutmentabutment止口 this diameter should conform to bearing manufacturers recommendations. in addition the radii (or undercut) between the abutment and bore should be also as per bearing manufacturers recommenda

20、tions else the bearing will not seat correctly and influence any preload values. 该直径应符合轴承制造商的建议。此外，轴承挡圈与轴承孔之间的倒圆角，应该也 是按照轴承制造商建议，否则轴承将不能正确安装和影响轴承作用到壳体上力的分布。 extraction extraction 拆卸拆卸 suitable consideration should be given to bearing (full or part such as outer race) extraction.this could take the f

21、orm of slots in the abutment face to allow a pulling tool. 适当考虑轴承（全部或部分，如外圈）的拆卸。可以采取在接触面增加槽的方式来 允许拆卸工具将轴承拆除。 bearing cagesbearing cages轴承保持架 in the case of taper roller bearings provision for bearing cage clearance may be required 在使用圆锥滚子轴承的情况下， 可能需要考虑轴承保持架的间隙。 lubrication lubrication 润滑润滑 the beari

22、ng will require adequate oil flow to ensure correct operation as well as cooling to extend the bearings life. 为提高轴承寿命，轴承将需要足够的润滑油，以确保正常的工作，以及冷却。 suitable galleries or slots to allow the oil to enter the bearing need to be designed. 设计时，需要设计合理的油槽或者油道，以保证润滑油能够对轴承进行润滑。 too many or positioned in the wro

23、ng place relative to the separation loads can lead to a reduction in both the casing and bearing stiffness. 油道或油槽布置不合理会产生相应的分离力，从而降低壳体和轴承的刚度 two similar approaches to directing oil to bearings (also up the shaft center drilling) 两种相似的润滑轴承的方法（轴中心钻孔也可以） preload and torque values - metric coarse pitch

24、series 预紧力和预紧扭矩- 公制粗牙系列 thread size grade 8.8 nominal preload pt n torque nm torque tolerance nm m4x0.735652.90.4 m5x0.857655.80.9 m6x181619.81.5 (m7x1)1173316.42.5 m8x1.251486023.83.2 (m9x1.25)19529353.7 m10 x1.523548474.3 m12x1.7534226825.9 (m14x2)466901318.2 m16x26374220412 fasteners in this case

25、 refers to mounting of casings halves or covers using threaded bolts and screws 用于连接变速箱壳体的紧固件包括螺栓和 螺钉。 the fasteners ensure when properly loaded that the joint face integrity is not impeded and therefore maintain the transmissions oil carrying capacity. 当变速箱传递扭矩时，连接螺栓确保壳体 连接面不分离，从而保证连接面的密封性 能。 to do

26、 this a suitable number of fasteners correctly spaced and sized having the correct torque applied will ensure this. 为了满足以上要求，必须正确的布置紧固件的数量，选择合适大小的紧固件以及预紧扭矩。 however a few rules should be employed to help. for tapping and drill depths refer the existing ricardo guidelines. 可以根据一些简单规则来选择紧固件。根据现有的里卡多手册

27、来确定攻丝和钻孔的深度。 spacing between bolts will determine the contact patch between the two casing halves around the flange ensuring a good seal. as a rule of thumb should be no greater than 8 x bolt 螺栓间的间隔将决定两壳体接触面间的密封性能。作为一个经验法则，螺栓间距不大于8*螺栓直径。 recommended thread engagement 有效啮合长度 有效啮合长度 fastener grade 紧固件

28、等级 female thread material内螺纹材料 grey cast iron 灰铸铁 steel 钢 aluminium 铝合金 up to 8.81.5d1.0d2.0d 10.91.5d1.2d2.5d 11.92.0d1.2d2.5d 12.92.0d1.5d3.0d source ricardo fastener guidelines extract only 螺纹孔尺寸-粗牙 clearances for tightening the fastener should be considered. typical methods include 必须考虑紧固件工具的安装空

29、间。 典型的安装方法包括： spanners, open, and ring 呆扳手、梅花扳手 power operated tools with socket driving tools. 使用套头的电动工具 bolt patterns with a high number bolts as well as being built in high volumes will use the latter therefore full consideration should be given to these tools and there preferred clearances. 将来，会

30、出现很多在体积大的结构 上装配很多螺栓的情况，因此必须考虑 在这种情况下，安装工具所需的安装间 隙。 对于六角头紧固件安装间距要求 source ricardo fastener guidelines 1.5 2 x d not recommended 不建议 al 1 x d mg - 1.125xd al-1xd mg 1.125xd d flange joints 凸缘连接 flange joint stiffness will ensure the fasteners will do their job correctly 凸缘连接处刚度将确保紧固件正确地完成他们 的工作 mg spe

31、cific 镁合金的特别要求 allow for the lower modulus compressive property.允许较低的抗压模量属性 use large fillets可以使用大倒角 avoid tapping breaking through boss 通过凸台避免攻丝破坏 smooth transition of form 过度形式平稳 make flanges 50% cast iron bolt patterns compared to cast iron 与铸铁相比螺栓的要求 smaller bolts小螺栓 half the spacing间距减 differen

32、t arrangements for improving flange stiffness without adding more material 在不增加材料的前提下，提高凸缘强度的不同方法 pull direction 拔模方向 6mm min land width for sealant 为了密封，宽度最小为6mm o ring arrangement o型密封圈结构 good sealing solution low volume only 降低结构体积的同时提高密 封性 motorsport typical application赛车的典型应用 caution o ring can

33、 expand and extrude 注意-o型密封圈可能被挤压变形 to overcome this some applications use a trapezoid shaped groove 为了克服这种情况，使用梯形沟槽 ric ard o plc 20 06 cast 45 x 2 or radius chamfer ensures beading of silicon sealant沿半径方向45倒角确保硅密封胶 密封良好 prevents contamination of gearbox 防止污染变速箱 not recommended 不推荐 joint of unequal

34、 section 变截面过渡连接 连接端面与主体的筋一般在 过渡处有过渡角 aluminium & magnesium铝、镁 height of wall in mm draft in degrees taper per 25mm 0.40150.11 1.0090.16 2.5060.26 6.3040.44 10.0030.52 16.002.50.7 25.0020.87 over 2520.87 largerthan 200mm = 1possible minium wall thickness - pressure die casting 最薄壁厚-压力铸造 sizemin thic

35、kness small10cm0.9mm medium300cm1.5mm largeover 300cm1.5-2.5mm unprotected aluminium & magnesium is more resistant to atmosphere than mild stee 没有采取保护措施的情况下，铝和镁比低碳钢更不容易生锈 corrosion resistance decreases slightly as wall thickness increases 随着壁厚的增加，壳体耐腐蚀性略有降低 galvanic corrosion between dissimilar mate

36、rials e.g steel and magnesium 考虑异性材料间的电偶腐蚀，例如钢铁和镁 good design can reduce the effects 好的设计能够减少以下影响 ensuring adequate drainage 确保合理的排水 washer/spacer to prevent direct contact between dissimilar materials 在异性材料之间增加垫片/间隙，防止的直接接触 bolt head design 螺栓头设计 good casting design to prevent dust and water accumu

37、lation 好的壳体设计能够防止灰尘和水分积聚 use of surface treatments on transmission casings 表面处理工艺被用在变速箱壳体设计中 none for automotive underbonnet applications also the case for magnesium applications 镁合金变速箱使用该工艺 painting civil aircraft 喷漆-民用飞机 hard anodising military aircraft 硬质阳极氧化- 军用飞机 keronite good design 好的设计 bad d

38、esign 不好的设计 electrolyte accumulation 电解质积累 effective drainage 有效的排水 example : steel washer & mg casing example : use a hard anodised aluminium washer with mg casings 在镁合金壳体上使用硬质阳极氧化铝垫圈 painting civil aviation 喷漆-民航 recommended minimum protection 推荐最低保护措施 preceded by a chromate conversion coating to

39、act as a key for the paint 由铬酸盐转化为涂层这个过程是喷漆 工艺的关键 hard anodise military aviation硬质阳极氧化- 军用航空 forms thick abrasion resistant coating 表面形成厚的耐磨涂料 inherent porosity requiring sealing to form a duplex film 形成双面膜提高固有孔隙的密封性 keronite produces a hard ceramic layer preliminary for magnesium 在镁的表面产生一层坚硬的陶瓷层 in

40、creases abrasive wear resistance - 增加 耐磨性 provides corrosion protection- 提供防腐蚀 保护 reduces fatigue strength of treated alloy less than hard anodising 降低合金处理时的疲劳强度 -比硬阳极氧化低 transmission noise 变速箱噪音 result of transmission errors 变速箱设计错误所致 shaft stiffness 轴刚度 gear micro geometry 齿轮微观几何 housing flex 壳体柔性

41、 poor housing design can magnify these errors 壳体的错误设计可以放 大这些错误 large flat areas on casings can flex壳体上大面积平面区域 增大壳体柔性 change the frequency of these panels by 通过一下方式改变平面固有频率 ribs 筋 step 阶梯特征 stepped surface cast iron gray灰铸铁 advantages优点 cheapest castable material价格便宜 good castability良好的铸造性能 strength强

42、度 very large castings possible可铸造超大型铸件 thermal expansion similar to steel热膨胀性跟钢 类似 disadvantages缺点 weight重量 machinability of hard outer skin外表面的可加工 能力 aluminium alloy 铝合金 advantages over iron 相比铸铁的优势 many casting techniques available铸造工艺多样性 sand砂型铸造 gravity die重力铸造 low pressure die低压铸造 high pressure

43、 die高压铸造 heat treatable to improve properties通过热处理来 提高毛坯性能 high resistance to shock loading高耐冲击性能 machinability加工性能 good corrosion resistance 良好的耐腐蚀性 disadvantages over iron- 相对于铸铁的缺点 thermal expansion needs to be accounted for when supporting gears and shaft需要考虑热膨胀对齿轮和轴孔的 影响 magnesium alloy 镁合金 adv

44、antages over aluminium 相对于铝合金的优点 strength to weight ratio强度重量比 machinablity v good 加工性能良好 damping ability阻尼能力 excellent die casting properties 卓越的压铸性能 thin wall sections possible 壁可以更薄 extended die life 模具寿命更长 faster material flow材料流动性能更好 higher pressures possible压力可以更高 disadvantages over aluminium-

45、 相对于铝合金的缺 点 low elastic modulus弹性模量低 high notch sensitivity缺口敏感性高 low hardness硬度低 corrosion hazard potential 潜在的腐蚀危险 recycle ability回收能力 as with all analysis, approximations in models, loading and interpretation exist, and real components may vary in geometry and properties from those assumed. hence

46、 analysis results should be used only as a tool for guiding the design process and for reducing risk of poor performance during development and validation testing. where analysis results are described as acceptable, it is implied only that the risk of poor performance is considered acceptable to pro

47、ceed to the next stage of the design and development process, unless otherwise stated. while the analysis may reduce the amount of testing required to prove a design, it should not be considered a replacement for validation testing unless specifically stated by ricardo. materials-why weight 材料-重量因 素

48、 why weight is an issue in transmission casings 为什么在变 速箱壳体设计时需考虑重量因素 cost 成本 reduced weight is reduced material cost 降低重量就 是在降低成本 to reduce overall vehicle weight 降低整车重量 improvements in vehicle performance提高整车如下性 能 acceleration加速性能 emissions排放 fuel consumption燃油经济性 improvements in safety提高安全性能 braki

49、ng effort制动性能 crash energy碰撞能量 获得同 样载荷 时体积 质量对 比 as with all analysis, approximations in models, loading and interpretation exist, and real components may vary in geometry and properties from those assumed. hence analysis results should be used only as a tool for guiding the design process and for r

50、educing risk of poor performance during development and validation testing. where analysis results are described as acceptable, it is implied only that the risk of poor performance is considered acceptable to proceed to the next stage of the design and development process, unless otherwise stated. w

51、hile the analysis may reduce the amount of testing required to prove a design, it should not be considered a replacement for validation testing unless specifically stated by ricardo. suitable casting processsand casting 铸造工艺砂型铸造 sand casting砂型铸造砂型铸造 the pouring of molten metal into a sand mould熔融金属的

52、 浇注到一个砂型 advantages优点 low equipment cost- 设备成本低 largest size of castings possible- 可铸造尺寸较大铸件 suited to complex shapes and cores- 适用于形状复杂的 件 very low gas porosity possible-气密性好 versatile- 多功能 as with all analysis, approximations in models, loading and interpretation exist, and real components may var

53、y in geometry and properties from those assumed. hence analysis results should be used only as a tool for guiding the design process and for reducing risk of poor performance during development and validation testing. where analysis results are described as acceptable, it is implied only that the ri

54、sk of poor performance is considered acceptable to proceed to the next stage of the design and development process, unless otherwise stated. while the analysis may reduce the amount of testing required to prove a design, it should not be considered a replacement for validation testing unless specifi

55、cally stated by ricardo. suitable casting processsand casting 铸造工艺砂型铸造 disadvantages缺点 wall thickness limitations- 壁厚有一定限制 poor linear tolerance 4mm/m- 铸造公差难以保证，4 毫米/米 rough surface finish 6.5-12.5 microns-表面粗糙，粗糙 度为6.5-12.5微米 coarser grain size than permanent mould castings- 表面颗 粒比金属型铸造大 as with al

56、l analysis, approximations in models, loading and interpretation exist, and real components may vary in geometry and properties from those assumed. hence analysis results should be used only as a tool for guiding the design process and for reducing risk of poor performance during development and val

57、idation testing. where analysis results are described as acceptable, it is implied only that the risk of poor performance is considered acceptable to proceed to the next stage of the design and development process, unless otherwise stated. while the analysis may reduce the amount of testing required

58、 to prove a design, it should not be considered a replacement for validation testing unless specifically stated by ricardo. suitable casting process gravity die casting铸造工艺 重力铸造 gravity die casting重力铸重力铸造造 the pouring of molten metal into a permanent mould under gravity or low pressure在重力或低压的作用下将熔融金

59、属的 压入金属性模具中 advantages优点 low cost than die casting- 比压铸成本低 higher casting rate than sand- 比砂铸铸造效率高 finer grain size 更高的表面质量 high quality castings -铸件质量更好 less finishing & polishing required - 表面抛光要求低 as with all analysis, approximations in models, loading and interpretation exist, and real component

60、s may vary in geometry and properties from those assumed. hence analysis results should be used only as a tool for guiding the design process and for reducing risk of poor performance during development and validation testing. where analysis results are described as acceptable, it is implied only th