车辆专业-YC1040轻型载货汽车驱动桥毕业设计说明书模板.doc
车辆专业-YC1040轻型载货汽车驱动桥毕业设计【含CAD图纸、说明书】
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中国重汽HOWO 悍将 117马力 4.2米轻卡1、整车性能参数序 号主 要 内 容参 数1发动机最大功率 (kw)852发动机最大输出扭矩 (N.m)3253主减速比 5.3754轮距 (mm)18256轴距 (mm)33607变速器一档传动比6.08满载后桥载荷 (kg)41009汽车满载重心高度 (mm)86510路面附着系数0.911轮胎7.50-16LT 6PR12最高转速 (r/min)220013整车重量 (kg)2305压缩包内含有CAD图纸和说明书,咨询Q 197216396 或 11970985轻型载货汽车驱动桥设计作 者 姓 名:指 导 教 师:单 位 名 称:机械工程与自动化学院专 业 名 称:车辆工程 Drive axle design 毕业设计(论文)任务书毕业设计(论文)题目:轻型载货汽车驱动桥设计基本内容:(1) 满足如下设计参数要求:总质量:6000kg;装载质量:3000kg;轴距:4000mm;后轮距1500mm;钢板弹簧座中心距离:865mm;满载时前轴荷1900kg;满载时后轴荷4100kg;最大功率70kw/3200r/min;最大转矩200Nm/2200r/min;(2) 进行总体方案分析,总体参数设计和计算,完成总体设计全部内容;(3) 进行零部件设计好校核计算,标准件选择和校核等;(4) 完成总体和主要零部件二维设计;(5) 撰写毕业设计说明书(6) 翻译一篇与汽车相关的外文文献毕业设计(论文)专题部分:题目:基本内容:学生接受毕业设计(论文)题目日期第周指导教师签字: 年月日II 摘 要轻型汽车在商用汽车生产中占有很大的比重,而且驱动桥在整车中十分重要。驱动桥作为汽车四大总成之一,它的性能的好坏直接影响整车性能,而对于载货汽车显得尤为重要。为满足目前当前载货汽车的快速、高效率、高效益的需要时,必须要搭配一个高效、可靠的驱动桥。设计出结构简单、工作可靠、造价低廉的驱动桥,能大大降低整车生产的总成本,推动汽车经济的发展,并且通过对汽车驱动桥的学习和设计实践,可以更好的学习并掌握现代汽车设计与机械设计的全面知识和技能,所以本题设计一款结构优良的轻型货车驱动桥具有一定的实际意义。本文首先确定主要部件的结构型式和主要设计参数,在分析驱动桥各部分结构形式、发展过程及其以往形式的优缺点的基础上,确定了总体设计方案,采用传统设计方法对驱动桥各部件主减速器、差速器、半轴、桥壳进行设计计算并完成校核。最后运用CAXA完成装配图和主要零件图的绘制。关键词:轻型货车;驱动桥;主减速器;差速器;半轴;桥壳II东北大学毕业设计 Abstract Abstract Pickup trucks take a large proportion of commercial vehicles production, and the drive axle is one of the most important structure. Drive axle is the one of automobile four important assemblies, Its performance directly influence on the entire automobile, especially for the truck .Because using the big power engine with the big driving torque satisfied the need of high speed, heavy-loaded, high efficiency, high benefit today truck, must exploiting the high driven efficiency single reduction final drive axle is becoming the trucks developing tendency. Design a simple, reliable, low cost of the drive axle, can greatly reduce the total cost of vehicle production, and promote the economic development of automobile and automotive drive axle of the study and design practice, can better learn and to master modern automotive design and mechanical design of a comprehensive knowledge and skills, so the title of the fine structure of the design of a pickup vehicle drive axle has a certain practical significance.In this paper, first of all determine the structure of major components and the main design parameters, the analysis of the various parts of the structure of the bridge drive type, the form of the development process and its advantages and disadvantages of the past, determined on the basis of the design program, using the traditional design method of various parts of the drive axle Main reducer, differential, axle, axle housing was designed to calculate and complete the check. Finally complete the final assembly drawing by using CAXA and mapping the main components.Keywords: Pickup truck; Drive axle; final drive; Differential; Axle; Drive Axle housingIII东北大学毕业设计 目录 目 录毕业设计(论文)任务书摘 要ABSTRACT第 1 章 绪 论11.1 选题背景目的及意义11.2 国内外驱动桥研究状况21.3 设计主要内容和预期成果4第2章 驱动桥的总体方案确定5 2.1 驱动桥结构种类和设计要求52.1.1 汽车车桥的种类 52.1.2 驱动桥的种类52.1.3 驱动桥的组成62.1.4 驱动桥的设计要求6 2.2 主减速器结构方案的确定72.2.1 主减速比的计算72.2.2 主减速器的齿轮类型82.2.3 主减速器的减速形式92.2.4 主减速器从动锥齿轮的支持形式及安装方法11 2.3 差速器结构方案的确定13 2.4 半轴形式的确定14 2.5 桥壳形式的确定15 2.6 本章小结16第3章 主减速器设计17 3.1 概述17 3.2 主减速器齿轮参数的选择与强度计算173.2.1 主减速器齿轮计算载荷的确定173.2.2 主减速器齿轮参数的选择193.2.3 螺旋锥齿轮的强度计算223.2.4 主减速器的轴承计算30 3.3 主减速器齿轮材料及热处理37 3.4 主减速器斜齿圆柱齿轮的参数选择和设计计算38 3.5 本章小结41第4章 差速器的设计43 4.1 对称式圆锥行星齿轮式差速器的设计计算444.1.1 行星齿轮数444.1.2 行星齿轮球面半径和节锥距444.1.3 行星齿轮和半轴齿轮齿数444.1.4 行星齿轮和半轴齿轮节锥角及模数444.1.5 半轴齿轮与行星齿轮齿形参数454.1.6 压力角454.1.7 行星齿轮安装孔直径及其深度的确定45 4.2 对称式圆锥行星齿轮差速器的材料47 4.3 对称式圆锥行星齿轮差速器的强度计算48第5章 驱动车轮的传动装置设计49 5.1 半轴的设计与计算49 5.2 半轴的结构设计及材料与热处理52第6章 驱动桥壳的设计53 6.1 桥壳的受力分析及强度计算53 6.1.1 桥壳的静弯曲应力计算53 6.1.2 在不平路面冲击作用下的桥壳强度计算55 6.1.3 汽车以最大牵引力行驶时的桥壳强度计算56 6.1.4 汽车紧急制动时的桥壳强度计算57 6.1.5 受最大侧向力时的桥壳强度计算59第7章 经济性和环保性分析61第8章 结论62致谢63参考文献64附录 65 第1章 绪 论1.1 选题背景目的及意义在我国轻型货车占有较大市场,据中国汽车工业协会统计,截至2007年底,国内轻型货车(1.8吨16时,取=0。=1612.43.2.2 主减速器齿轮参数的选择1、 主、从动齿数的选择 选择主、从动锥齿轮齿数时应考虑如下因素:为了磨合均匀,之间应避免有公约数;为了得到理想的齿面重合度和高的轮齿弯曲强度,主、从动齿轮齿数和应不小于40;为了啮合平稳,噪声小和具有高的疲劳强度对于商用车一般不小于6;主传动比较大时,尽量取得小一些,以便得到满意的离地间隙。对于不同的主传动比,和应有适宜的搭配。主减速器的传动比为6.14,初定主动齿轮齿数z1=21,从动齿轮齿数z2=43。2、从动锥齿轮节圆直径及端面模数的选择 根据从动锥齿轮的计算转矩(见式3.1和式3.2并取两式计算结果中较小的一个作为计算依据,按经验公式选出: (3.5) 式中:直径系数,取=1316;计算转矩,取,较小的。取=6675.46。计算得,=244.78301.26mm,初取=301mm。 选定后,可按式算出从动齿轮大端模数,并用下式校核 (3.6) 式中:模数系数,取=0.30.4;计算转矩,取。 =5.677.53由GB/T12368-1990,取=7,满足校核。所以有:=147mm =301mm。3、螺旋锥齿轮齿面宽的选择 通常推荐圆锥齿轮从动齿轮的齿宽F为其节锥距的0.3倍。对于汽车工业,主减速器螺旋锥齿轮面宽度推荐采用:=0.155=46.66mm,可初取=50mm。一般习惯使锥齿轮的小齿轮齿面宽比大齿轮稍大,使其在大齿轮齿面两端都超出一些,通常小齿轮的齿面加大10%较为合适,在此取=55。4、螺旋锥齿轮螺旋方向 主、从动锥齿轮的螺旋方向是相反的。螺旋方向与锥齿轮的旋转方向影响其所受的轴向力的方向。当变速器挂前进挡时,应使主动锥齿轮的轴向力离开锥顶方向。这样可使主、从动齿轮有分离的趋势,防止轮齿因卡死而损坏。所以主动锥齿轮选择为左旋,从锥顶看为逆时针运动,这样从动锥齿轮为右旋,从锥顶看为顺时针,驱动汽车前进。5、 旋角的选择 螺旋角是在节锥表面的展开图上定义的,齿面宽中点处为该齿轮的名义螺旋角。螺旋角应足够大以使1.25。因越大传动就越干稳,噪声就越低。在一般机械制造用的标准制中,螺旋角推荐用35。6、法向压力角a的选择 压力角可以提高齿轮的强度,减少齿轮不产生根切的最小齿数,但对于尺寸小的齿轮,大压力角易使齿顶变尖及刀尖宽度过小,并使齿轮的端面重叠系数下降,一般对于“格里森”制主减速器螺旋锥齿轮来说,载货汽车可选用20压力角。7、主从动锥齿轮几何计算计算结果如表3.1 表3.1 主减速器齿轮的几何尺寸计算用表序号项 目计 算 公 式计 算 结 果1主动齿轮齿数212从动齿轮齿数433模数74齿面宽b=55mm=50mm5工作齿高10.92mm6全齿高=12.131mm7法向压力角=208轴交角 =909节圆直径=147mm=301mm10节锥角arctan=90-=26.03=63.9711节锥距A=A=167mm12周节t=3.1416 t=21.99mm13齿顶高=9.03mm=1.89mm14齿根高=3.101mm=10.241mm15径向间隙c=c=1.211mm16齿根角=1.065=3.5117面锥角;=29.58=65.03518根锥角=24.9=60.12819外圆直径=163mm=303mm20节锥顶点止齿轮外缘距离=146.5mm=71.8mm21理论弧齿厚=14.27mm=8.82mm22齿侧间隙B=0.3050.4060.32mm23螺旋角=353.2.3螺旋锥齿轮的强度计算1、损坏形式及寿命在完成主减速器齿轮的几何计算之后,应对其强度进行计算,以保证其有足够的强度和寿命以及安全可靠性地工作。在进行强度计算之前应首先了解齿轮的破坏形式及其影响因素。齿轮的损坏形式常见的有轮齿折断、齿面点蚀及剥落、齿面胶合、齿面磨损等。它们的主要特点及影响因素分述如下:(1)轮齿折断 主要分为疲劳折断及由于弯曲强度不足而引起的过载折断。折断多数从齿根开始,因为齿根处齿轮的弯曲应力最大。 疲劳折断:在长时间较大的交变载荷作用下,齿轮根部经受交变的弯曲应力。如果最高应力点的应力超过材料的耐久极限,则首先在齿根处产生初始的裂纹。随着载荷循环次数的增加,裂纹不断扩大,最后导致轮齿部分地或整个地断掉。在开始出现裂纹处和突然断掉前存在裂纹处,在载荷作用下由于裂纹断面间的相互摩擦,形成了一个光亮的端面区域,这是疲劳折断的特征,其余断面由于是突然形成的故为粗糙的新断面。 过载折断:由于设计不当或齿轮的材料及热处理不符合要求,或由于偶然性的峰值载荷的冲击,使载荷超过了齿轮弯曲强度所允许的范围,而引起轮齿的一次性突然折断。 为了防止轮齿折断,应使其具有足够的弯曲强度,并选择适当的模数、压力角、齿高及切向修正量、良好的齿轮材料及保证热处理质量等。齿根圆角尽可能加大,根部及齿面要光洁。(2)齿面的点蚀及剥落 齿面的疲劳点蚀及剥落是齿轮的主要破坏形式之一,约占损坏报废齿轮的70%以上。它主要由于表面接触强度不足而引起的。点蚀:是轮齿表面多次高压接触而引起的表面疲劳的结果。由于接触区产生很大的表面接触应力,常常在节点附近,特别在小齿轮节圆以下的齿根区域内开始,形成极小的齿面裂纹进而发展成浅凹坑,形成这种凹坑或麻点的现象就称为点蚀。一般首先产生在几个齿上。在齿轮继续工作时,则扩大凹坑的尺寸及数目,甚至会逐渐使齿面成块剥落,引起噪音和较大的动载荷。在最后阶段轮齿迅速损坏或折断。减小齿面压力和提高润滑效果是提高抗点蚀的有效方法,为此可增大节圆直径及增大螺旋角,使齿面的曲率半径增大,减小其接触应力。在允许的范围内适当加大齿面宽也是一种办法。齿面剥落:发生在渗碳等表面淬硬的齿面上,形成沿齿面宽方向分布的较点蚀更深的凹坑。凹坑壁从齿表面陡直地陷下。造成齿面剥落的主要原因是表面层强度不够。例如渗碳齿轮表面层太薄、心部硬度不够等都会引起齿面剥落。当渗碳齿轮热处理不当使渗碳层中含碳浓度的梯度太陡时,则一部分渗碳层齿面形成的硬皮也将从齿轮心部剥落下来。(3)齿面胶合 在高压和高速滑摩引起的局部高温的共同作用下,或润滑冷却不良、油膜破坏形成金属齿表面的直接摩擦时,因高温、高压而将金属粘结在一起后又撕下来所造成的表面损坏现象和擦伤现象称为胶合。它多出现在齿顶附近,在与节锥齿线的垂直方向产生撕裂或擦伤痕迹。轮齿的胶合强度是按齿面接触点的临界温度而定,减小胶合现象的方法是改善润滑条件等。(4)齿面磨损 这是轮齿齿面间相互滑动、研磨或划痕所造成的损坏现象。规定范围内的正常磨损是允许的。研磨磨损是由于齿轮传动中的剥落颗粒、装配中带入的杂物,如未清除的型砂、氧化皮等以及油中不洁物所造成的不正常磨损,应予避免。汽车主减速器及差速器齿轮在新车跑合期及长期使用中按规定里程更换规定的润滑油并进行清洗是防止不正常磨损的有效方法。汽车驱动桥的齿轮,承受的是交变负荷,其主要损坏形式是疲劳。其表现是齿根疲劳折断和由表面点蚀引起的剥落。在要求使用寿命为20万千米或以上时,其循环次数均以超过材料的耐久疲劳次数。因此,驱动桥齿轮的许用弯曲应力不超过210.9Nmm.表3.2给出了汽车驱动桥齿轮的许用应力数值。 表3.2汽车驱动桥齿轮的许用应力 ( Nmm)计算载荷 主减速器齿轮的许用弯曲应力主减速器齿轮的许用接触应力差速器齿轮的许用弯曲应力,中的较小者7002800980210.91750210.9 实践表明,主减速器齿轮的疲劳寿命主要与最大持续载荷(即平均计算转矩)有关,而与汽车预期寿命期间出现的峰值载荷关系不大。汽车驱动桥的最大输出转矩和最大附着转矩并不是使用中的持续载荷,强度计算时只能用它来验算最大应力,不能作为疲劳损坏的依据。2、主减速器螺旋锥齿轮的强度计算(1)单位齿长上的圆周力 在汽车主减速器齿轮的表面耐磨性,常常用其在轮齿上的假定单位压力即单位齿长圆周力来估算,即 (3.7)式中:单位齿长上的圆周力,N/mm; P作用在齿轮上的圆周力,N,按发动机最大转矩和最大附着力矩两种载荷工况进行计算。按发动机最大转矩计算时: (3.8)式中:发动机输出的最大转矩,在此取200; 变速器的传动比; 主动齿轮节圆直径,在此取49mm.;按上式计算一档时: Nmm直接档时: Nmm。表3.3 许用单位齿长上的圆周力 (Nmm)类别档位一档二档直接档轿车893536321载货汽车1429250公共汽车982214牵引汽车536250按最大附着力矩计算时: (3.9)式中:汽车满载时一个驱动桥给水平地面的最大负荷,对于后驱动桥还应考虑汽车最大加速时的负荷增加量,在此取40180N; 轮胎与地面的附着系数,在此取0.85; 轮胎的滚动半径,在此取0.405m;按上式=1838.13 Nmm。虽然附着力矩产生的p很大,但由于发动机最大转矩的限制p最大只有986.13 N/mm可知,校核成功。(2)轮齿的弯曲强度计算 汽车主减速器螺旋锥齿轮轮齿的计算弯曲应力为 (3.10)式中:齿轮计算转矩,对从动齿轮,取,较小的者即=6675.46和=1612.4来计算;对主动齿轮应分别除以传动效率和传动比得=1132.51,=273.54;超载系数,1.0; 尺寸系数=0.7245; 载荷分配系数取=1; 质量系数,对于汽车驱动桥齿轮,档齿轮接触良好、节及径向跳动精度高时,取1;J计算弯曲应力用的综合系数,见图3.1,=0.242,=0.181。求综合系数J的齿轮齿数图3.1 弯曲计算用综合系数J按计算: 主动锥齿轮弯曲应力=359.45 Nmm700 Nmm从动锥齿轮弯曲应力=507.27 Nmm700 Nmm按计算:主动锥齿轮弯曲应力=116.08 Nmm210.9 Nmm从动锥齿轮弯曲应力=122.53 Nmm210.9Nmm综上所述由表3.2,计算的齿轮满足弯曲强度的要求。(3)轮齿的接触强度计算 螺旋锥齿轮齿面的计算接触应力(Nmm)为: (3.11)式中:主动齿轮计算转矩分别为=1132.51,=273.54;材料的弹性系数,对于钢制齿轮副取232.6;主动齿轮节圆直径,49mm;,同3.10;尺寸系数,=1; 表面质量系数,对于制造精确的齿轮可取1; F齿面宽,取齿轮副中较小值即从动齿轮齿宽50mm;大齿轮齿数 J 计算应力的综合系数,J =0.135,见图3.2所示。小齿轮齿数接触强度计算用J图3.2 接触强度计算综合系数J按计算,=2749.782800 Nmm 按计算,=1351.411750 Nmm由表3.2轮齿齿面接触强度满足校核。(4)主动齿轮轴的弯矩 如图3.3所示为主动齿轮受力及弯矩图。图3.3 主动齿轮轴弯矩图 危险截面上的合成弯曲应力为 : (3.12)式中: 弯曲截面系数,,D=35mm;主动齿轮计算转矩为273.54危险截面弯矩,主动齿轮径向力为3091.05N。经计算,=66.7MPa=230MPa所以主动齿轮轴满足要求。3.2.4主减速器的轴承计算轴承的计算主要是计算轴承的寿命。设计时,通常是先根据主减速器的结构尺寸初步确定轴承的型号,然后验算轴承寿命。影响轴承寿命的主要外因是它的工作载荷及工作条件,因此在验算轴承寿命之前,应先求出作用在齿轮上的轴向力、径向力、圆周力,然后再求出轴承反力,以确定轴承载荷。1、作用在主减速器主动齿轮上的力如图3.4所示锥齿轮在工作过程中,相互啮合的齿面上作用有一法向力。该法向力可分解为沿齿轮切向方向的圆周力、沿齿轮轴线方向的轴向力及垂直于齿轮轴线的径向力。 图3.4 主动锥齿轮工作时受力情况为计算作用在齿轮的圆周力,首先需要确定计算转矩。汽车在行驶过程中,由于变速器挡位的改变,且发动机也不全处于最大转矩状态,故主减速器齿轮的工作转矩处于经常变化中。实践表明,轴承的主要损坏形式为疲劳损伤,所以应按输入的当量转矩进行计算。作用在主减速器主动锥齿轮上的当量转矩可按下式计算:(3.13)式中:发动机最大转矩,在此取200Nm;,变速器在各挡的使用率,可参考表3.4选取0.5,2,5,15,77.5;,变速器各挡的传动比6.01,3.82,2.44,1.55,1;,变速器在各挡时的发动机的利用率,可参考表3.4选取50,60,70,70,60。表3.4及的参考值变速器档位车型轿车公共汽车载货汽车III挡IV挡IV挡IV挡带超速档IV挡IV挡带超速档V挡80I IIIIIIVV19901420750.82.51680.72627651415501311850.53.57590.5251577.5IIIIIIIVV60 60507065606065605050707060607070606050607060506070705060707060注:表中,其中发动机最大转矩,;汽车总重,。经计算=193.732 Nm齿面宽中点的圆周力P为:=9459.57N (3.14)式中:T作用在该齿轮上的转矩。主动齿轮的当量转矩; 该齿轮齿面宽中点的分度圆直径。对于螺旋锥齿轮 所以:40.96mm =251.64mm; 从动齿轮的节锥角80.753。计算螺旋锥齿轮的轴向力与径向力根据条件选用表3.5中公式。表3.5 圆锥齿轮轴向力与径向力主动齿轮轴向力径向力螺旋方向旋转方向右左顺时针反时针右左反时针顺时针主动齿轮的螺旋方向为左;旋转方向为顺时针:=7204.88 N (3.15)= 3091.05 N (3.16)从动齿轮的螺旋方向为右:旋转方向为逆时针: =3091.05(N) (3.17) =7204.88(N) (3.18)式中:齿廓表面的法向压力角20; 主动齿轮的节锥角26.07;从动齿轮的节锥角63.97。2、主减速器轴承载荷的计算轴承的轴向载荷就是上述的齿轮的轴向力。但如果采用圆锥滚子轴承作支承时,还应考虑径向力所应起的派生轴向力的影响。而轴承的径向载荷则是上述齿轮的径向力,圆周力及轴向力这三者所引起的轴承径向支承反力的向量和。当主减速器的齿轮尺寸,支承形式和轴承位置已初步确定,计算出齿轮的轴向力、径向力圆周力后,则可计算出轴承的径向载荷。对于采用悬臂式的主动锥齿轮和跨置式的从动锥齿轮的轴承径向载荷,如图3.5所示图3.5 主减速器轴承的布置尺寸轴承A,B的径向载荷分别为= (3.19) (3.20)式中:已知=9459.57N,=3091.05N,=7204.88N , 40.96mm, a=43mm,b=26mm,c=69mm。所以,轴承A的径向力=5929.29 N 轴承B的径向力=12255.52 N轴承的寿命为 s (3.21)式中: 为温度系数,在此取1.0;为载荷系数,在此取1.2;Cr额定动载荷,N:其值根据轴承型号确定。此外对于无轮边减速器的驱动桥来说,主减速器的从动锥齿轮轴承的计算转速为 r/min (3.22)式中:轮胎的滚动半径,0.405m; 汽车的平均行驶速度,km/h;对于载货汽车和公共汽车可取3035 km/h,在此取32.5 km/h。所以有上式可得=213.45 r/min主动锥齿轮的计算转速=213.456.14=1310.58 r/min。所以轴承能工作的额定轴承寿命: h (3.23)式中: 轴承的计算转速,1310.50r/min。若大修里程S定为100000公里,可计算出预期寿命即 = h (3.24) 所以=3076.9 h对于轴承A和B,在此并不是单独一个轴承,而是一对轴承,根据尺寸,在此选用30207型轴承,d=35mm,D=72mm,Cr=54.2KN,e=0.37对于轴承A,在此径向力=5929.29N,轴向力A=7204.88N,所以=1.21eX=0.4,Y=1.6当量动载荷 Q= (3.25)式中:冲击载荷系数在此取1.2;所以,Q=1.2(0.45929.29+1.67204.88)=16679.4N。由于采用的是成对轴承=2Cr,所以轴承的使用寿命为:=6514.5 h3076.9 h=所以轴承A符合使用要求。对于轴承B,径向力=12255.53N,轴向力A=7204.88,所以=0.47eX=0.4,Y=1.6当量动载荷 Q= (3.26)式中:冲击载荷系数在此取1.2;所以,Q=1.2(0.412255.53+1.67204.88)=19715.7N=3731.02 h3076.9 h=所以轴承B符合使用要求。 对于从动齿轮的轴承C,D的径向力R= (3.27) (3.28)已知:P=9459.57N,=3091.05N,=7204.88N,a=240mm,b=124mm.c=116mm所以,轴承C的径向力:=4887.4N;轴承D的径向力:=9939.38N根据尺寸,轴承C,D均采用32103,其额定动载荷Cr为82.8KN,D=100mm,d=65mmT=23mm,e=0.35对于轴承C,轴向力A=3091.05N,径向力=4887.4N,并且=0.63e, X=0.4,Y=1.7所以Q=1.2(0.43091.051.79939.38)=2176.03N =6716.17所以轴承C满足使用要求。对于轴承D,轴向力A=0N,径向力R=23100.5N,X=1,Y=0。所以Q=9939.38N=91507.36 h 所以轴承D满足使用要求12。3.3 主减速器齿轮材料及热处理驱动桥锥齿轮的工作条件是相当恶劣的,与传动系的其它齿轮相比,具有载荷大,作用时间长,载荷变化多,带冲击等特点。其损坏形式主要有齿轮根部弯曲折断、齿面疲劳点蚀(剥落)、磨损和擦伤等。根据这些情况,对于驱动桥齿轮的材料及热处理应有以下要求:1、具有较高的疲劳弯曲强度和表面接触疲劳强度,以及较好的齿面耐磨性,故齿表面应有高的硬度;2、轮齿心部应有适当的韧性以适应冲击载荷,避免在冲击载荷下轮齿根部折断;3、钢材的锻造、切削与热处理等加工性能良好,热处理变形小或变形规律易于控制,以提高产品的质量、缩短制造时间、减少生产成本并将低废品率;4、选择齿轮材料的合金元素时要适合我国的情况。汽车主减速器用的螺旋锥齿轮以及差速器用的直齿锥齿轮,目前都是用渗碳合金钢制造。在此,齿轮所采用的钢为20CrMnTi用渗碳合金钢制造的齿轮,经过渗碳、淬火、回火后,轮齿表面硬度应达到5864HRC,而心部硬度较低,当端面模数8时为2945HRC。对于渗碳深度有如下的规定:当端面模数m5时, 为0.91.3mm 当端面模数m58时,为1.01.4mm由于新齿轮接触和润滑不良,为了防止在运行初期产生胶合、咬死或擦伤,防止早期的磨损,圆锥齿轮的传动副(或仅仅大齿轮)在热处理及经加工(如磨齿或配对研磨)后均予与厚度0.0050.010mm的磷化处理或镀铜、镀锡。这种表面不应用于补偿零件的公差尺寸,也不能代替润滑。对齿面进行喷丸处理有可能提高寿命达25。对于滑动速度高的齿轮,为了提高其耐磨性,可以进行渗硫处理。渗硫处理时温度低,故不引起齿轮变形。渗硫后摩擦系数可以显著降低,故即使润滑条件较差,也会防止齿轮咬死、胶合和擦伤等现象产生。3.4 主减速器斜齿圆柱齿轮的参数选择与设计计算二级主减采用斜齿圆柱齿轮。1.选用七级精度,材料选择选择小齿轮的材料为40Cr (调质)硬度为280HBS,大齿轮的材料为45钢(调质),硬度为240 HBS,二者材料硬度相差40HBS;初选小齿轮的齿数为15,大齿轮的齿数为45,初选螺旋角为14;2.按齿面接触强度设计根据公式 d选=1.6;由文献7图10-30选择区域系数ZH=2.433;由文献7图10-26查得=0.7, =0.78,所以=+=1.48;材料的弹性影响系数为Z=189.8MPa;文献7表10-21d查得小齿轮的接触疲劳强度极限=600 Mpa,大齿轮的为=550 Mpa;文献7由式10-13计算应力循环次数 N1=2.8810 N2=1.37110;文献7由图10-19取接触疲劳寿命系数K=0.95,K=0.98;计算接触疲劳许用应力 取失效概率为1%, 安全系数为S=1,由式10-12得 =576 Mpa,=539 Mpa,许用接触应力为=(576+539)/2=557.5 Mpa;取齿宽系数为=1;小齿轮传递的转矩为5371.5310;把所有数据代入以上的公式得到d;3.计算圆周速度v=6.09m/s ;4.计算齿宽以及模数mnt b= d=174.48 , mnt=11.29, h=2.25mnt =25.4, b/h=6.87;5.纵向重合度为=1.189;使用系数为KA=1,由文献7图10-8得动载荷系数K=1.11,由表10-4查得K=1.450;由文献7图10-13查得 K=1.35;由文献7表10-3查得K=K=1.2 所以载荷系数为K=KA K K K=1.931;6.按实际的载荷系数校正所算得的分度圆直径为d1= d=184.95;7.由齿面接触计算模数m=11.96;8.按齿根弯曲强度设计: 计算载荷系数 K=KA K KK=1.798;螺旋影响系数=0.87;计算当量齿数 Z=16.41 Z=49.23;查得齿形系数 Y=3.09, Y=2.35,由表10-5查得Y=1.50,Y=1.70;小齿轮的弯曲疲劳强度极限=500 Mpa.大齿轮的为=380 Mpa;计算弯曲疲劳安全系数 s=1.4,1=303.57, 2=236.14;计算大小齿轮的Y Y/1 =0.01527, Y Y/2=0.01692大齿轮的数值大代入最初公式计算得出mn9.30;疲劳强度计算的法面模数mn大于由齿根弯曲疲劳强度计算的法面模数,取mn=10,可满足弯曲强度.但为了同时满足接触疲劳强度,需按接触疲劳强度算得的分度圆直径来计算应有的齿数,于是由Z=17.95.选择Z=17,则Z=173.03=51.51,选择Z=50;9.几何尺寸计算:a=310.28mm 取为310mm;按圆整后的中心距修正螺旋角arccos=13.83;计算大小齿轮的分度圆直径 d=156.19mm 取为156mm;用以上公式计算得 =464.32mm 取为464mm;计算齿轮的宽度为 =158mm, 圆整后取mm;计算得出齿顶圆 小齿轮直径为180mm , 大齿轮的直径为486mm;齿根圆 小齿轮的直径为140mm,大齿轮的直径为446mm。3.5 本章小结本章根据所给参数确定了主减速器计算载荷、并根据有关的机械设计、机械制造的标准对齿轮参数进行合理的选择,最后对螺旋锥齿轮的相关几何尺寸参数进行列表整理,并且对主动、从动齿轮进行强度校核。对主减速器齿轮的材料及热处理,主减速器的润滑给以说明。东北大学毕业设计 第4章 差速器的设计 第4章 差速器的设计根据汽车行驶运动学的要求和实际的车轮,道路以及它们之间的相互关系表明:汽车在行使过程中,左右车轮在同一时间内所滚过的路程往往是不相等的,左右两轮胎内的气压不等、胎面磨损不均匀、两车轮上的负荷不均匀而引起车轮滚动半径不相等;左右两轮接触的路面条件不同,行使阻力不等等。这样,如果驱动桥的左、右车轮刚性连接,则不论转弯行使或直线行使,均会引起车轮在路面上的滑移或滑转,一方面会加剧轮胎磨损、功率和燃料消耗,另一方面会使转向沉重,通过性和操纵稳定性变坏。为此,在驱动桥的左右车轮间都装有轮间差速器。差速器是个差速传动机构,用来在两输出轴间分配转矩,并保证两输出轴有可能以不同的角速度转动,用来保证各驱动轮在各种运动条件下的动力传递,避免轮胎与地面间打滑。汽车差速器有齿轮式、凸轮式、蜗轮式和牙嵌自由轮式等多种结构型式。普通的对称式圆锥齿轮差速器由差速器左右壳,两个半轴齿轮,四个行星齿轮,行星齿轮轴,半轴齿轮垫片及行星齿轮垫片等组成。如图4.1所示。由于其具有结构简单、工作平稳、制造方便、用于公路汽车上也很可靠等优点,故广泛用于各类车辆上。图4.1 普通的对称式圆锥行星齿轮差速器1,12-轴承;2-螺母;3,14-锁止垫片;4-差速器左壳;5,13-螺栓;6-半轴齿轮垫片;7-半轴齿轮;8-行星齿轮轴;9-行星齿轮;10-行星齿轮垫片;11-差速器右壳4.1 对称式圆锥行星齿轮差速器的设计计算4.1.1 行星齿轮数n通常情况下,货车的行星齿轮数n=4;4.1.2 行星齿轮球面半径Rb和节锥距A 行星齿轮球面半径Rb反映了差速器锥齿轮节锥矩的大小和承载能力;Rb=Kb (4.1)式中:Kb行星齿轮球面半径系数,Kb=2.52-2.99;Td计算转矩,为8628.25Nm;将各参数代入式(4.1),有:Rb=61.32 mm 选为62mm; A=(0.98-0.99) Rb=0.99x62=61.38mm 选为 62mm;4.1.3 行星齿轮和半轴齿轮齿数z1和z2为了使轮齿有较高的强度,z1一般不少于10。半轴齿轮齿数z2在1425选用。大多数汽车的半轴齿轮与行星齿轮的齿数比在1.52.0的范围内,且半轴齿轮齿数和必须能被行星齿轮齿数整除。查阅文献,经方案论证,初定半轴齿轮与行星齿轮的齿数比=1.5,半轴齿轮齿数z2=24,行星齿轮的齿数 z1=16。4.1.4 行星齿轮和半轴齿轮节锥角1、2及模数m行星齿轮和半轴齿轮节锥角1、2分别为 1= (4.2) 2= (4.3)将各参数分别代入式(4.2)与式(4.3),有:1=3341,2=5619锥齿轮大端模 m= (4.4)将各参数代入式(4.4),有:m=4.3;最终取模数m=5;4.1.5 半轴齿轮与行星齿轮齿形参数按文献1设计计算方法进行设计和计算,结果见表4.1。4.1.6 压力角目前,汽车差速器的齿轮大都采用22.5的压力角,齿高系数为0.8。最小齿数可减少到10,并且在小齿轮(行星齿轮)齿顶不变尖的条件下,还可以由切向修正加大半轴齿轮的齿厚,从而使行星齿轮与半轴齿轮趋于等强度。由于这种齿形的最小齿数比压力角为20的少,故可以用较大的模数以提高轮齿的强度。在此选22.5的压力角。4.1.7 行星齿轮安装孔直径及其深度L的确定=8628.25Nm ; ; 134.4 ; l=0.5=67.2; =27.99 L=1.131; 式中:T0差速器壳传递的转矩,Nm;n行星齿轮数;传动效率,取为0.9;c 支承面许用挤压应力,取69 MPa;表4.1半轴齿轮与行星齿轮参数序号项目计算公式计算结果1行星齿轮齿数10,应尽量取小值=162半轴齿轮齿数=1425=243模数=5mm4齿面宽b=(0.250.30)A;b10m19mm5工作齿高=8mm6周节t=3.1416mt=15.7087全齿高8.991mm8压力角22.59轴交角=9010节圆直径; 11节锥角,=3341,=561912节锥距=62mm13齿顶高; =5.03mm =2.97mm14齿根高=1.788-;=1.788-=3.91mm;=5.97mm15径向间隙=-=0.188+0.051=0.991mm16齿根角=;=3.61 =5.5017面锥角;=39.19 =59.9318根锥角; =30.07 =50.8219外圆直径;mmmm20节圆顶点至齿轮外缘距离mmmm21理论弧齿厚=9.142 mm=9.708mm22齿侧间隙=0.2450.330 mm=0.25mm23弦齿厚=9.28mm=9.58mm24弦齿高=7.80mm=3.57mm4.2 对称式圆锥行星齿轮差速器的材料差速器齿轮和主减速器齿轮一样,基本上都是用渗碳合金钢制造,目前用于制造差速器锥齿轮的材料为20CrMnTi、20CrMoTi、22CrMnMo和20CrMo等。由于差速器齿轮轮齿要求的精度较低,所以精锻差速器齿轮工艺已被广泛应用。4.3 对称式圆锥行星齿轮差速器的强度计算差速器齿轮的尺寸受结构限制,而且承受的载荷较大,它不像主减速器齿轮那样经常处于啮合传动状态,只有当汽车转弯或左、右轮行使不同的路程时,或一侧车轮打滑而滑转时,差速器齿轮才能有啮合传动的相对运动。因此,对于差速器齿轮主要应进行弯曲强度计算。轮齿弯曲应力w(MPa)为 (4.5)式中:n差速器行星齿轮的数目;J综合系数,取0.225;F半轴齿轮齿宽,mm;d2半轴齿轮大端分度圆直径,mm;T差速器一个行星齿轮给予一个半轴齿轮的转矩(Nm),T=0.6 T/n;T为计算转矩;k、ks、km、kv、m 与以上说明相同;将各参数代入式中,有:w=734.57 Mpa ; Mpa差速器齿轮的ww=980 MPa,=210.9 Mpa,所以齿轮弯曲强度满足要求。东北大学毕业设计 第5章 驱动车轮的传动装置设计 第5章 驱动车轮的传动装置设计驱动车轮的传动装置位于汽车传动系的末端,其功用是将转矩由差速器半轴齿轮传给驱动车轮。在断开式驱动桥和转向驱动桥中,驱动车轮的传动装置包括半轴和万向节传动装置且多采用等速万向节。在一般非断开式驱动桥上,驱动车轮的传动装置就是半轴,这时半轴将差速器半轴齿轮与轮毂连接起来。在装有轮边减速器的驱动桥上,半轴将半轴齿轮与轮边减速器的主动齿轮连接起来。5.1 半轴的设计与计算半轴的主要尺寸是它的直径,设计与计算时首先应合理地确定其计算载荷。半轴的计算应考虑到以下三种可能的载荷工况:a)纵向力X2最大时(X2Z2)附着系数尹取0.8,没有侧向力作用;b)侧向力Y2最大时,其最大值发生于侧滑时,为Z2中,侧滑时轮胎与地面侧向附着系数,在计算中取1.0,没有纵向力作用;c)垂向力Z2最大时,这发生在汽车以可能的高速通过不平路面时,其值为(Z2-gw)kd,kd是动载荷系数,这时没有纵向力和侧向力的作用;由于车轮承受的纵向力、侧向力值的大小受车轮与地面最大附着力的限制,即: ;故纵向力X2最大时不会有侧向力作用,而侧向力Y2最大时也不会有纵向力作用。本课题采用带有凸缘的全浮式半轴,其详细的计算校核如下: a)全浮式半轴计算载荷的确定 全浮式半轴只承受转矩,其计算转矩按下式进行:T=Temaxig1i0 (5.1)式中:差速器的转矩分配系数,对圆锥行星齿轮差速器可取0.6; ig1变速器1挡传动比; i0主减速比; 已知:Temax200Nm;ig17.64; i06.14 ;=0.6由公式(5.1)计算结果: T=0.62007.646.14=10657.8Nm在设计时,全浮式半轴杆部直径的初步选取可按下式进行: (5.2)式中d半轴杆部直径,mm; T半轴的计算转矩,Nm; T10657.8 Nm;半轴扭转许用应力,MPa; 根据上式(5.2) :得:45.11mmd47.96mm取:d=46mm; 全浮式半轴支承转矩,其计算转矩为: (5.3)三种半轴的扭转应力由下式计算: (5.4)式中半轴的扭转应力,MPa;T半轴的计算转矩,T=10657.8Nm;d半轴杆部直径,d=46mm; 将数据带入式(5.3)、(5.4)得:=557.94MPa MPa半轴花键的剪切应力为 (5.5)半轴花键的挤压应力为 (5.6)式中:T半轴承受的最大转矩,T=10657.8Nm;DB半轴花键(轴)外径,DB=57mm;dA相配的花键孔内径,dA=51.38mm;z花键齿数;z=18;Lp花键工作长度,Lp=168mm;b花键齿宽,B=4.71mm;载荷分布的不均匀系数,取0.75。 将数据带入式(5.5)、(5.6)得:=36.82Mpa Mpa=61.72MPa Mpa所以符合要求.半轴的最大扭转角为 (5.7)式中T半轴承受的最大转矩,T=10657.8Nm;L半轴长度,l=900mm;G材料的剪切弹性模量,MPa;J半轴横截面的极惯性矩, mm4; 将数据带入式(5.7)得: = 8 半轴计算时的许用应力与所选用的材料、加工方法、热处理工艺及汽车的使用条件有关。当采用40Cr,40MnB,40MnVB,40CrMnMo,40号及45号钢等作为全浮式半轴的材料时,其扭转屈服极限达到784MPa左右。在保证安全系数在1.31.6范围时,半轴扭转许用应力可取为490588MPa。当传递最大转矩时,半轴花键的剪切应力不应超过71.05MPa;挤压应力不应该超过196MPa,半轴单位长度的最大转角不应大于8/m。 5.2 半轴的结构设计及材料与热处理为了使半轴的花键内径不小于其杆部直径,常常将加工花键的端部做得粗些,并适当地减小花键槽的深度,因此花键齿数必须相应地增加,通常取10齿(轿车半轴)至18齿(载货汽车半轴)。半轴的破坏形式多为扭转疲劳破坏,因此在结构设计上应尽量增大各过渡部分的圆角半径以减小应力集中。重型车半轴的杆部较粗,外端突缘也很大,当无较大锻造设备时可采用两端均为花键联接的结构,且取相同花键参数以简化工艺。在现代汽车半轴上,渐开线花键用得较广,但也有采用矩形或梯形花键的。半轴多采用含铬的中碳合金钢制造,如40Cr,40CrMnMo,40CrMnSi,40CrMoA,35CrMnSi,35CrMnTi等。40MnB是我国研制出的新钢种,作为半轴材料效果很好。半轴的热处理过去都采用调质处理的方法,调质后要求杆部硬度为HB388444(突缘部分可降至HB248)。近年来采用高频、中频感应淬火的口益增多。这种处理方法使半轴表面淬硬达HRC5263,硬化层深约为其半径的13,心部硬度可定为HRC3035;不淬火区(突缘等)的硬度可定在HB248277范围内。由于硬化层本身的强度较高,加之在半轴表面形成大的残余压应力,以及采用喷丸处理、滚压半轴突缘根部过渡圆角等工艺,使半轴的静强度和疲劳强度大为提高,尤其是疲劳强度提高得十分显著。由于这些先进工艺的采用,不用合金钢而采用中碳(40号、45号)钢的半轴也日益增多。东北大学毕业设计(论文) 第6章 驱动桥壳的设计第6章 驱动桥壳的设计驱动桥桥壳是汽车上的主要零件之一,非断开式驱动桥的桥壳起着支承汽车荷重的作用,并将载荷传给车轮作用在驱动车轮上的牵引力、制动力、侧向力和垂向力也是经过桥壳传到悬挂及车架或车厢上。因此桥壳既是承载件又是传力件,同时它又是主减速器、差速器及驱动车轮传动装置(如半轴)的外壳。在汽车行驶过程中,桥壳承受繁重的载荷,设计时必须考虑在动载荷下桥壳有足够的强度和刚度。为了减小汽车的簧下质量以利于降低动载荷、提高汽车的行驶平顺性,在保证强度和刚度的前提下应力求减小桥壳的质量桥壳还应结构简单、制造方便以利于降低成本。其结构还应保证主减速器的拆装、调整、维修和保养方便。在选择桥壳的结构型式时,还应考虑汽车的类型、使用要求、制造条件、材料供应等。6.1 桥壳的受力分析及强度计算汽车驱动桥的桥壳是汽车上的主要承载构件之一,其形状复杂,而汽车的行驶条件如道路状况、气候条件及车辆的运动状态又是千变万化的,首先应先分析一下汽车满载静止于水平路面时桥壳最简单的受力情况,即进行桥壳的静弯曲应力计算。6.1.1 桥壳的静弯曲应力计算桥壳犹如一空心横梁,两端经轮毂轴承支承于车轮上,在钢板弹簧座处桥壳承受汽车的簧上载荷,而左、右轮胎的中心线,地面给轮胎的反力(双轮胎时则沿双胎中心),桥壳则承受此力与车轮重力之差值,即(),计算简图如6.2所示。 图6.1 桥壳静弯曲应力计算简图桥壳按静载荷计算时,在其两钢板弹簧座之间的弯矩为 Nm (6.1) 式中:汽车满载时静止于水平路面时驱动桥给地面的载荷,在此40180N; 车轮(包括轮毂、制动器等)重力,N; 驱动车轮轮距,在此为1500mm; 驱动桥壳上两钢板弹簧座中心间的距离,在此为865mm。桥壳的危险断面通常在钢板弹簧座附近。通常由于远小于,且设计时不易准确预计,当无数据时可以忽略不计所以 =9261Nm而静弯曲应力则为 MPa (6.2)式中:见(6.1); 危险断面处(钢板弹簧座附近)桥壳的垂向弯曲截面系数,具体见下:截面图如图6.3所示,其中B=160mm, H=193mm, h=127mm, =28mm,=33mm.H=193mm, 图6.2 钢板弹簧座附近桥壳的截面图垂向弯曲截面系数: =809341.35mm水平弯曲截面系数: =674656.53mm扭转截面系数: =233132160=1393920mm关于桥壳在钢板弹簧座附近的危险断面的形状,主要由桥壳的结构形式和制造工艺来确定,从桥壳的使用强度来看,矩形管状(高度方向为长边)的比圆形管状的要好。所以在此采用矩形管状。根据上式桥壳的静弯曲应力=11.44 MPa6.1.2 在不平路面冲击载荷作用下的桥壳强度计算当汽车在不平路面上高速行驶时,桥壳除承受静止状态下那部分载荷外,还承受附加的冲击载荷。在这两种载荷总的作用下,桥壳所产生的弯曲应力为 MPa (6.3)式中:动载荷系数,对于载货汽车取2.5; 桥壳在静载荷下的弯曲应力 ,MPa。根据上式 MPa6.1.3 汽车以最大牵引力行驶时的桥壳强度计算为了使计算简化,不考虑侧向力,仅按汽车作直线行驶的情况进行计算,另从安全系数方面作适当考虑。如图6.4所示为汽车以最大牵引力行驶的受力简图。图6.3 汽车以最大牵引力行驶的受力简图作用在左右驱动车轮的转矩所引起的地面对于左右驱动车轮的最大切向反作用力共为 N (6.4)根据上式可计算得=31408.06N由于设计时某些参数未定而无法计算出汽车加速行驶时的质量转移系数值,而对于载货汽车的后驱动桥可在1.11.3范围内选取,在此取1.2。 此时后驱动桥桥壳在左、右钢板弹簧座之间的垂向弯矩为 Nm (6.5)式中:,见式(6.1)下的说明。根据上式=11113.2 Nm由于驱动车轮所承受的地面对其作用的最大切向反作用力,使驱动桥壳也承受着水平方向的弯矩,对于装有普通圆锥齿轮差速器的驱动桥,由于其左、右驱动车轮的驱动转矩相等,故有 Nm (6.6)所以根据上式=4240.09Nm桥壳还承受因驱动桥传递驱动转矩而引起的反作用力矩,这时在两钢板弹簧座间桥壳承受的转矩为 = Nm (6.7) 式中:发动机最大转矩,在此为372Nm; 传动系的最低传动比; 传动系的传动效率,在此取0.9;根据上式可计算得=7993.35 Nm所以在钢板弹簧座附近的危险断面处的弯曲应力和扭转应力分别为 MPa (6.8) MPa (6.9)式中:分别为桥壳在两钢板弹簧座之间的垂向弯矩和水平弯矩,见式(6.5),和式(6.6); 分别为桥壳在危险断面处的垂向弯曲截面系数,水平弯曲截面系数和扭转截面系数。根据上式可以计算得=20 MPa =5.73 MPa由于桥壳的许用弯曲应力为500 MPa,许用扭转应力为400MPa,所以该设计的桥壳满足这种条件下的强度要求。6.1.4 汽车紧急制动时的桥壳强度计算这时不考虑侧向力,图6.5为汽车在紧急制动时的受力简图。图6.4 汽车在紧急制动时的受力简图由于设计时一些参数是未知的,所以后驱动桥计算用的汽车紧急制动时的质量转移系数不可计算,一般对于载货汽车后驱动桥取0.750.95。图6.6为汽车紧急制动时后驱动桥壳的受力分析简图,此时作用在左右驱动车轮上除了有垂向反作用力外,尚有切向反力,即地面对驱动轮的制动力,因此可求得紧急制动时桥壳在两钢板弹簧座之间的垂向弯矩及水平方向的弯矩分别为 (6.10) = (6.11)式中:,见式(6.1)下的说明; 汽车制动时的质量转移系数,计算后驱动桥时=0.85; 驱动车轮与路面的附着系数,计算时可取0.750.80,在此取0.8;根据上式可以计算得=9960.3Nm =7968.24 Nm 图6.5 汽车紧急制动时后驱动桥的受力简图桥壳在两钢板弹簧座的外侧部分处同时还承受制动力所引起的转矩,对于后驱动桥: Nm (6.12) 根据上式=11871.92 Nm所以可根据式(6.8),(6.9)计算出在钢板弹簧座附近危险断面的弯曲应力和扭转应力分别为 =24 MPa =8.5 MPa由于桥壳的许用弯曲应力为500 MPa,许用扭转应力为400 MPa,所以该设计的桥壳满足这种条件下的强度要求。 6.1.5受最大侧向力时的桥壳强度计算外轮和内轮的垂直反力为 F,F F=G0.5- (6.13)式中:侧向力附着系数; 满载质心高;1.2 m; 轮距 1500 mm;由F=0可得值将以上各值代入(5.13)中 0=G0.5- 有=0.725弯矩 M= Fb- Fr b=368mm ; r=0.509m ;F= G=40180 N M=5063N.m =3.63N/ 强度满足要求。东北大学毕业设计(论文) 第7章 经济性和环保性分析第7章 经济性和环保性分析随着目前国际上石油价格的上涨,汽车的经济性日益成为人们关心的话题,这不仅仅只对载货汽车,对于其他车型,提高其燃油经济性也是各商用车生产商来提高其产品市场竞争力的一个法宝。为了降低油耗,不仅要在发动机的环节上节油,而且也需要从传动系中减少能量的损失。这就必须在发动机的动力输出之后,在从发动机传动轴驱动桥这一动力输送环节中寻找减少能量在传递的过程中的损失。在这一环节中,发动机是动力的输出者,也是整个机器的心脏,而驱动桥则是将动力转化为能量的最终执行者。因此,在发动机相同的情况下,采用性能优良且与发动机匹配性比较高的驱动桥便成了有效节油的措施之一。此外,随着社会各界环保意识的不断提高,对汽车的燃油经济性也有了更高的要求,因而对汽车排放问题也越来越受到国家环保部门的重视。我国的汽车环保取得了很大成绩。通过狠抓汽车环保工作, 从欧到欧,已经连续上了几个台阶。业内权威人士认为, 汽车环保是一个系统工程, 涉及到多个方面, 废旧汽车回收, 零部件回收,汽车空气、清洁能源等等, 这其中, 政府应当也必须起到关键作用, 比如说, 加大力度进一步完善汽车环保相关的法津法规和标准,建立具体可行的监管机制加强监管; 在消费环节上也要适当予以政策方面的优惠; 尤其是政府要优先采购国内节能环保的汽车等等。通过这些实际步骤来有力推动自主品牌汽车的环保建设落到实处, 取得实效。随着这些技术的成功研发和不断完善, 汽车污染将被极大地降低。东北大学毕业设计(论文) 第8章 结论第8章 结 论本课题设计的轻型货车的驱动桥,采用非段开式驱动桥与非独立悬架相适应,由于结构简单、工作可靠,可以被广泛用在各种轻型载货汽车之中。本设计介绍了后桥驱动的零部件结构及其整体结构,计算了主减速器、差速器、以及半轴的结构尺寸,并对其进行了强度校核,桥壳的校核也是一个不容忽视的问题此设计从多方面对桥壳进行了校核从而保证了驱动桥的安全性。并绘制了有关零件图和装配图。本驱动桥设计满足其设计要求,结构合理,符合实际应用,具有很好的动力性和经济性,驱动桥总成及零部件的设计能尽量满足零件的标准化、部件的通用化和产品的系列化及汽车变型的要求,修理、保养方便,机件工艺性好,制造容易。汽车驱动桥设计涉及的机械零部件及元件的品种极为广泛,对这些零部件、元件及总成的制造也几乎涉及到所有的现代机械制造工艺。因此,通过对汽车驱动桥的学习和设计实践,可以更好的学习现代汽车设计与机械设计的知识和技能。东北大学毕业设计(论文) 致谢致 谢本次毕业设计历时三个多月,从选题、开题设计到绘制装配图、零件图,完成说明书。其间每一过程都得到王永富老师的悉心指导,老师严谨治学的态度和学识的渊博给我带来了深刻的印象.老师堪称良师益友,不仅教给我丰富的知识还教导我面对困难要勇于战胜的积极态度,在此表示衷心的感谢。同时还要感谢东北大学图书馆及相关书籍的作者,感谢他们为我们提供了丰富的资料。四年的大学生活就快走入尾声,我们的校园生活就要划上句号,心中是无尽的难舍与眷恋。从这里走出,对我的人生来说,将是踏上一个新的征程,要把所学的知识应用到实际工作中去。回首四年,取得了些许成绩,生活中有快乐也有艰辛。感谢老师四年来对我孜孜不倦的教诲,对我成长的关心和爱护。 毕业设计虽然结束了,大学四年的学习生活也即将结束,但这只是人生的一个新的开始。我的知识,特别是在机械专业方面的知识还刚刚是打下了一个良好的基础,学无止境,还有很多问题需要我去研究,去探索。因此,在以后的工作和学习生活中,我将继续保持对机械的无限热情,勇于探索,大胆创新,争取在本专业有所成就。 东北大学毕业设计(论文) 参考文献参考文献1 刘惟信.汽车设计.第一版.北京:清华大学出版社,2001年.275-403.2 刘惟信.驱动桥设计. 第一版.北京:清华大学出版社,2004年.3 王望予. 汽车设计. 北京:机械工业出版社, 2007.4 陈家瑞. 汽车构造. 北京:机械工业出版社,2003.5 徐灦. 机械设计手册. 北京:机械工业出版社,1991.6 机械设计手册编委会编著. 机械设计手册. 北京:机械工业出版社,2004.7 濮良贵,纪名刚. 机械设计.第八版.北京:高等教育出版社,2006.204-233.8 孙桓, 陈作模, 葛文杰. 机械原理. 第七版. 北京:高等教育出版社,2006.177-201.9 北京齿轮厂编译. 格利森锥齿轮技术资料:译文集. 北京:机械工业出版社,1983.10成大先,王德夫. 设计机械手册.第一版.化学工业出版社,2004.11 马立峰. 圆柱齿轮几何尺寸查算手册.第一版.技术标准出版社,1981.12 余志生. 汽车理论. 北京:机械工业出版社, 1990.附录英文原文:Development of Integrated Motor Assist Hybrid System: Development of the Insight, a Personal Hybrid Coupe Kaoru Aoki, Shigetaka Kuroda, Shigemasa Kajiwara, Hiromitsu Sato and Yoshio YamamotoHonda R&D Co.,Ltd.Copyright 2000 Society of Automotive Engineers, Inc.ABSTRACT This paper presents the technical approach used to design and develop the powerplant for the Honda Insight, a new motor assist hybrid vehicle with an overall development objective of just half the fuel consumption of the current Civic over a wide range of driving conditions. Fuel consumption of 35km/L (Japanese 10-15 mode), and 3.4L/100km (98/69/EC) was realized. To achieve this, a new Integrated Motor Assist (IMA) hybrid power plant system was developed, incorporating many new technologies for packaging and integrating the motor assist system and for improving engine thermal efficiency. This was developed in combination with a new lightweight aluminum body with low aerodynamic resistance. Environmental performance goals also included the simultaneous achievement of low emissions (half the Japanese year 2000 standards, and half the EU2000 standards), high efficiency, and recyclability. Full consideration was also given to key consumer attributes, including crash safety performance, handling, and driving performance.1. INTRODUCTION To reduce the automobiles impact on society and the environment requires that it be increasingly cleaner and more energy efficient. The issues of energy conservation, ambient air quality, and reduction in CO2 emissions are increasing raised as global environmental concerns. One solution for dealing with these issues is the hybrid automobile. Honda has developed and introduced to several major markets worldwide the Insight, a new generation of vehicle design. The Insight combines a hybrid power train with advanced body technology features to meet an overall goal of achieving the highest fuel economy practical.The hybrid power train is a motor assist parallel configuration, termed IMA for Integrated Motor Assist. This power train combines a highly efficient electric motor with a new small displacement VTEC engine, a lightweight aluminum body, and improved aerodynamics to realize 3.4L/100km (CO2:80g/km) on 98/69/EC fuel economy. Low emissions performance was also targeted with emission levels achieving the EU2000. In addition to recapturing deceleration energy, the integrated motor provides high torque assist during typical urban driving accelerations. This allows a significant reduction in engine displacement and higher engine efficiency. Sustained hill climbing performance and high speed cruising capability are assured by a power-toweight ratio of approximately 56kW per metric ton. New engine technology includes the application of a new VTEC (Variable valve Timing and valve lift, Electronic Control) cylinder head design promoting high efficiency and fast catalyst activation, and a new lean NOx catalyst system which promotes lean burn combustion and a reduction in emissions. Extensive friction and weight reducing features are also applied. 2. DEVELOPMENT TARGETS AND CONCEPT Development was aimed at the achievement of extremely low fuel consumption. We set a target of twice the fuel economy of the current production Civic, Hondas representative high fuel economy car at 7.0 L/100km (93/116/ EC). As a result, the Insight has the lowest fuel consumption in the world, among gasoline passenger cars.Exhaust emission performance often tends to be sacrificed for the sake of low fuel consumption. However, we also decided to match the low emissions performance achieved by other mass production cars. Consideration was also given to recyclability (another important environmental issue), crash safety performance, and the basic car characteristics including handling and styling.Summarizing the above, our development targets were as follows: The best fuel consumption performance in the world Ultra-low exhaust emissions Superior recyclability The worlds highest level of crash safety performance Advanced styling Practical features and responsive handling Comfortable two-seat configuration with personal utility space 3. POLICIES FOR FUEL CONSUMPTION REDUCTION In order to establish the technical approach for achieving the fuel consumption target, we conducted a detailed analysis of the energy consumption of the base car, a Civic equipped with a 1.5 liter engine. We found that it was useful to divide the targeted efficiency gains roughly into thirds, as shown in Fig.A 1, in order to achieve the low fuel consumption and numerous other above-mentioned goals. These divisions are as follows. Improvement of the heat efficiency of the engine itself Recovery of braking energy and employment of idle stop using a hybrid power plant Car body technologies including reduction of weight and reduced aerodynamic and rolling resistance. Figure A1. Target of double the fuel economy of CIVICAiming to establish a benchmark for 21st century automobile power trains, we developed this new Integrated Motor Assist power train. This power train simultaneously achieves both extremely low fuel consumption of 3.4L/100km, and low exhaust gas emission performance, befitting a next-generation car. This paper reports on the newly developed IMA system, including the lean burn engine, electric motor, power control unit, battery technology, and exhaust emission control technology used in the Honda Insight. 4. AIM OF THE IMA SYSTEM While developing this next-generation IMA hybrid system, we incorporated as many currently achievable technologies and techniques as possible, in order to achieve the worlds lowest fuel consumption.The following four system development themes were established in order to meet this target.1.Recovery of deceleration energy 2.Improvement of the efficiency of the engine 3.Use of idle stop system 4.Reduction of power train size and weight 5.OVERVIEW OF THE IMA SYSTEM 5.1. SYSTEM CONFIGURATION As shown in Fig.A 2, the IMA system uses the engine as the main power source and an electric motor as an auxiliary power source when accelerating. Using a motor as an auxiliary power source simplifies the overall system and makes it possible to use a compact and lightweight motor, battery, and power control unit (PCU).Figure A2. IMA SystemA permanent magnet DC brushless motor is located between the engine and the transmission. When decelerating, the rate of deceleration is calculated for each gear and the PCU controls the motor to generate electricity (recover energy), which charges a nickel-metal hydride battery. When accelerating, the amount of auxiliary power provided (hereafter called assist) is calculated from the throttle opening, engine parameters, and battery state of charge. The PCU controls the amount of current flowing from the battery to the drive motor 1.2. RECOVERY OF DECELERATION ENERGY Recovering deceleration energy through regeneration makes it possible to supplement the engines output during acceleration and reduce the amount of fuel consumed. Reducing resistance due to running losses, including engine frictional losses, increases the available energy for regeneration. In particular, minimizing the engine displacement is an effective means of reducing friction. Engine displacement reduction also has several other benefits, such as weight reduction and increased thermal efficiency. The IMA system effectively increases the amount of regeneration during deceleration by optimizing the engine and transmission specifications.1.3. REDUCTION OF ENGINE DISPLACEMENT Reducing engine displacement is a very important factor in improving fuel economy of a hybrid drive train. However, modern automobiles have to perform over a wide dynamic range. Reducing the displacement is equivalent to lowering the basic performance characteristics of the car. As shown in the output characteristics graph in Fig. A3, the IMA system assists the engine in the low rpm range by utilizing the hightorque performance characteristic of electric motors. The motor can increase overall toruque by over 50% in the lower rpm range used in normal driving. Output in the high rpm range is increased by using a Variable valve Timing and valve lift Electronic Control (VTEC) engine. Thus sufficient peak power is assured and makes it possible to use a new, small displacement 1.0 liter engine.Figure A3.Engine speed (rpm) Output performance of IMA SYSTEMAssist from the electric motor while accelerating is a very efficient means of reducing the amount of fuel consumed. 1.4. ACHIEVING LEAN BURN ENGINE OPERATION Assist from the electric motor, based upon the throttle opening, creates quite linear torque characteristics. This, in turn, improves driveability. In addition, motor assist is also provided under moderate load conditions to broaden the lean-burn operating range, bringing out the full potential of the newly developed lean burn engine. 1.5. IDLE STOP SYSTEM Stopping the engine rather than idling at stops is also an effective means for reducing fuel consumption. In order to restart the engine with the minimum amount of fuel consumption, the engine is quickly cranked to 600 rpm or more by the hightorque integrated motor before ignition occurs, as shown in Fig.A 4. This makes it possible to minimize the amount of fuel consumed, in addition to the fuel saved by not running the engine at idle. There are many issues to be considered when performing idle stop. These include judging the drivers intent to stop, preparing for the restart, providing a smooth feeling of deceleration, and minimizing vibration of the car body when the engine stops.Figure A4.Time (sec) The number of cranking in the engine start This IMA system results in the achievement of both very quick restarts and exceptionally smooth starts.6.MOTOR ASSIST MECHANISM 6.1. DEVELOPMENT OBJECTIVES By limiting the IMA motor functions to assistance and regeneration, development themes were established to achieve the following two points. 1. A simple and compact structure 2. A system weight of 10% (80 kg) or less of the completed car weight6.2. THIN PROFILE DC BRUSHLESS MOTOR A thin and compact DC brushless motor with engine assist and energy regeneration functions was coupled to the engine crank-shaft (Fig. A5).FigureA 5. Section view of Motor This is a high efficiency, compact, and lightweight permanent magnet-type three-phase synchronous electric motor with a maximum output of 10 kW. In addition to developing technologies to reduce the weight and increase efficiency, we also aimed to make the motor as thin as possible in order to achieve a compact power train. Lost wax precision casting process was used for the rotor, rotating by bending coupled to the crankshaft. This achieves high strength and lighter weight (approximately -20%) compared with normal cast products. For the rotor magnets, further improvements were made to the neodymium-sintered magnets used in the HONDA EV PLUS, realizing approximately 8% greater torque density and improved heat resistance. This design also results in a motor structure that does not require a cooling system. A split stator structure with salient pole centralized windings was developed and used to reduce the motor axial width. A split stator was adopted to drive the rotor. This makes it possible to use the salient pole centralized windings, which are both more compact and efficient than the conventional coil wave winding method, as shown in Fig.A 6. In addition, centralized distribution bus rings (Fig. A7) formed from copper sheets were used for the harness that supplies electricity to the coils on both sides of the stator. This results in an extremely compact and simple structure. These improvements achieve an extremely thin motor with a width of only 60 mm. This represents a 40% reduction in width compared to conventional technology. Wave winding Salient pole windingFigure A6. Compare of windingFigure A7. Cut view of Motor6.3. NICKEL-METAL HYDRIDE (NI-MH) BATTERY A nickel-metal hydride battery is used to store and provide electrical energy for the motor assist. This is an advanced battery which has already achieved proven results in the high specific energy version used for the HONDA EV PLUS electric vehicle. The hybrid vehicle battery features stable output characteristics, regardless of the state-of-charge status. It is also extremely durable in this application. The battery pack has an integrated structure consisting of 20 modules, each having sixD-size cells connected in series, arranged in a lattice formation. These 120 1.2 V cells are all connected in series for a total battery pack voltage of 144 V.6.4. POWER CONTROL UNIT (PCU) The PCU performs precise control of motor assist/regeneration and supplies power to the 12 V power source. It has built-in cooling functions, which give it a lightweight, efficient and compact structure. Significant weight reduction was achieved by integrating an air cooling system using highly efficient cooling fins and a magnesium heat sink case.The inverter for the drive motor, which is the most important component within the PCU, has switching elements integrated into a single module for generating the three-phase AC current. These were separate components on the EV PLUS. The drive circuit has been miniaturized and converted to an IC using high density integration. These improvements have resulted not only in significant weight reduction, but have also improved the power conversion efficiency. Further, using phase control to drive the motor at very high efficiencies reduces the amount of heat produced and makes it possible to use a lightweight and simple air-cooling system. (Fig.A 8) Figure A8.Inverter Cut view of PCU Heat Sink case7.ENGINE 7.1 DEVELOPMENT OBJECTIVES The following four points were set as development themes in order to achieve low fuel consumption over a wide range of operating conditions. 1. Improvement of thermal efficiency 2. Reduction of mechanical losses (-10% compared with conventional designs ) 3. Reduction of size and weight (lightest weight in its class) 4. Achievement of half the EU2000 standards 7.2 ENGINE OVERVIEW AND SPECIFICATIONS The engine specifications are shown in Table 1 and the main new features and their purposes are shown in Table 2. First, a displacement of approximately 1000 cm3 was considered optimal for this vehicle with the IMA system, so a 3-cylinder engine was selected to minimize combustion chamber surface-to-volume ratio and mechanical losses. (Fig. A9) 7.3 FUEL CONSUMPTION Engine displacement could be reduce considerably in the motor assist powertrain because of the motor assist enhancement of low rpm torque, and also VTEC for sufficient peak power output from the engine. A key feature of this engine is the significant improvement in combustion efficiency through lean burn technology. Technologies adopted to make this possible include new intake swirl ports, which enhance the swirl (mixture formation) inside the cylinders. A compact combustion chamber and a high compression ratio also help by improving the indicated heat efficiency. This result in significantly shorter combustion times compared to conventional lean burn engines, allowing combustion in a leaner range with a higher air-fuel ratio. This significantly improves the fuel consumption. The new high swirl ports and compact combustion chamber are evolutions based on conventional VTEC lean burn technology. In the conventional VTEC engine, swirl is produced by keeping one intake valve closed in low speed operating conditions. However, in this engine the intake valves and intake ports are arranged more vertically to produce strong eddies in the mixture flowing into the cylinders. The conventional VTEC configuration has the inlet and exhaust rocker arms each supported by a separate rocker shaft. The new VTEC mechanism shown in Fig.A10 combines these into a single rocker shaft, thus realizing a significant reduction in size. In addition, it narrows the valve included angle from 46 to 30, allowing a high swirl port shape and a very compact combustion chamber.Figure A9. Cutaway view of engineFigure A10. Section view of cylinder 7.4 REDUCTION OF MECHANICAL LOSS In addition to improvement of the indicated heat efficiency, reduction of mechanical loss is also important to improve fuel economy. To achieve this, the following the low friction technologies were used. Roller coaxial VTEC mechanism Piston micro-dimple treatment Offset cylinder structure Low tension piston rings Carburized connecting rods The roller coaxial VTEC structure (Fig.A 11) is an adaptation of technology used in the Honda S2000 (high output sportscar engine) to a single-cam VTEC mechanism. The camshaft drive loss was reduced by 70% using a needle roller bearing in the area where the rocker arm slides on the camshaft. In addition, simultaneous reduction in both weight and size were achieved by incorporating the VTEC switching piston into the roller bearing inner shaft. Piston micro-dimple treatment consists of treating the surface of the piston skirt to create a micro-dimple surface. This increases the oil film retention performance and can reduce friction by approximately 30% when lowfriction oil is used.Figure A11. Section view of Roller VTEC These effects resulted in the development of a 0W-20 grade low viscosity oil that complies with ILSAC standards. The friction reducing effects of super-low viscosity oil were measured by engine motoring. These measurement results are shown in Fig. A12. In the current technology engine, the HTHS viscosity at the limit friction value was approximately 2.5 mPas. Being used together with the advanced low friction engine, the limit value was lower than the current technology engine These low friction technologies have vastly reduced the overall engine friction, as shown in Fig. A13. In total, they have realized a reduction in friction of 10% or more compared to a conventional 1.0 liter engine design . Figure A12. Limit in friction reductionFigure A13. Engine friction7.5 WEIGHT REDUCTION The structure and materials of almost all parts in this engine have been reviewed with the aim of creating the lightest engine in the world in the 1.0 liter class. This weight reduction extends even to the skeleton structure technology and materials technology fields carburized connecting rods as used on the S2000 (high output sportscar engine). Carburization strength enhancement technology contributes greatly to increasing engine operational speed. We applied this strength enhancement technology to create a slim connecting rod design for the IMA engine. This resulted in a weight reduction of approximately 30% compared to conventional connecting rods. Most oil pans are made of steel plate or aluminum alloy. Conventional magnesium materials have had problems withstanding the high temperatures of engine oil. In contrast to conventional materials, which experience a significant drop in creep strength at 120C or higher, we have developed a new magnesium oil pan (Fig.A 14) which ensures sufficient creep strength up to 150C.Figure A14. Magnesium Oil PanThis oil pan is fastened using steel bolts with aluminum washers to prevent galvanic corrosion. The oil pan weight is 35% lighter than an aluminum oil pan, for a reduction in weight that is comparable to the ratio between the specific masses of the two metals. In order to expand the application of plastic parts, plastic materials were adopted for the intake manifold, cylinder head cover, water pump pulley, and intake system parts. These changes brought the discrete dry weight of the engine to less than 60 kg, which is the lightest weight in the world for the 1.0 liter class.7.6 EXHAUST EMISSION PERFORMANCE Technology for simultaneously achieving both lean burn and low exhaust emissions was adopted in this engine, achieving a notable reduction in NOx emissions. Combustion was improved by putting the exhaust system to the rear of the engine (Fig. A15). In addition, the exhaust manifold was integrated with the cylinder head and a NOx adsorption catalyst which reduces NOx emissions during lean burn operation was also newly developed.Figure A15. Section view of emission system 7.6.1Integrated Exhaust Manifold and Cylinder Head Conventional cylinder heads have independent exhaust ports for each cylinder and a separate exhaust manifold acts to converge these exhaust ports into a single port is then mounted to the head. However, the new head on the Insight has a structure which converges the exhaust ports into a single port inside the head, as shown in Fig. A16. This greatly reduces the weight. In addition, the small heat radiating surface area reduces the exhaust gas heat loss, thus enabling early catalyst activation.Figure A16. View of Head 7.6.2Lean NOx Catalyst The catalyst system on the Insight combines a conventional three-way catalyst with NOx adsorbing materials. The NOx conversion mechanism of the newly developed catalyst is shown in Fig. A17. The NOx in the exhaust gas is adsorbed and separated by the NOx adsorption action of the catalyst during lean engine operating conditions. Conventional three-way catalyst operation reduces part of the NOx to nitrogen and oxidizes most of the HC and CO to CO2 and H2O during lean operation. However, since the exhaust gas contains large amounts of oxygen, there is relatively little NOx reduction with the three-way catalyst and most of the NOx is stored on the surface of the adsorbing material. When the exhaust is held at the theoretical air fuel ratio (stoichiometry) or richer air-fuel ratio, the adsorbed NOx is reduced to nitrogen using HC and CO as reducing agents. The adsorbent is regenerated at the same time. Thus, NOx, HC and CO are effectively converted using the three-way catalytic action of the catalyst combined with the NOx adsorber. This type of catalyst exhibits superior conversion performance during both lean operation and stoichiometric operation by switching between lean and stoichiometry operating conditions. It is essential to create a regenerative atmosphere before the NOx adsorption capacity becomes overloaded. This catalyst directly adsorbs NOx during lean burn engine operation and the adsorbed NOx is then reduced and exhausted as harmless nitrogen (N2) during stoichiometric operation.Figure A17. Exhaust gas purification mechanism This catalyst is characterized by the direct adsorption of NOx to the catalyst surface during lean operation. Adsorption on the catalyst surface, instead of absorption as a compound inside the surface, facilitates conversion during reduction and also provides superior durability at high temperatures. This adsorptive type catalyst reduces NOx emissions during lean burn operation to 1/10 the level of the conventional three-way catalyst. It should be noted that the adsorption and conversion performance of this type of catalyst is sensitive to sulfur levels in the fuel, as sulfur can compete for the active NOx adsorbing sites. As a conventional three-way catalyst has virtually no NOx reduction during lean-operation, the lean burn operating range typically has to be reduced to keep NOx emissions down. Use of an adsorptive type catalyst maintains the full lean burn range and improves fuel economy, even while reducing NOx. This vehicle can also satisfy the EU2000 standards, making this a highly efficient lean burn engine that complies with exhaust emissions standards throughout the world. 8.CONCLUSION This paper presents a general overview of the recently developed motor assist hybrid powertrain, as well as a description of its various components and its output and emission performance. This hybrid power train simultaneously achieves ultra low fuel consumption and low exhaust emissions. It also achieves a compact, lightweight power train layout. We believe this system advances 21st century automotive technology toward regional and global environmental goals. REFERENCES 1. Aoki, Kaoru, et al.: Development an Integrated Motor Assist Hybrid System, JSAE No. 98-99 1612. Yamaguchi, Tetsuro: CVT Control in the HONDA Hybrid IMA, No. 9908 JSAE SYMPOSIUM, Latest Motive Power Transmission Technologies 99, p.37403. Ohno, Hiroshi, et al.: Development of a NOx Adsorptive Reaction Type Three-Way Catalyst, HONDA R&D Technical Review, Vol. 11 No. 2 (October 1999), p.45-50 4. Fukuo, Koichi, et al.: Development of the Ultra Low Fuel Consumption Hybrid Car Insight, HONDA R&D Technical Review, Vol. 11 No. 2 (October 1999), p.1-85. Hideki Tanaka, et al .: The Effect of 0W-20 Low Viscosity Engine Oil on Fuel Economy”, SAE Paper No.1999-01-3468,Fuels and Lubricants meeting and Exposition, Toronto, Ontario, Canada, October 1999. 6. Aoki, Kaoru, et al.: An Integrated Motor Assist Hybrid System, SAE Paper No.2000-01-2059, Government / Industry Meeting, Washington, D.C., USA中文翻译集成式发动机辅助混合动力系统 摘要 本论文介绍了用于设计和开发Honda Insight发动机的技术方法,一种新的发动机辅助混合动力汽车,其总开发目标是在广泛的行驶条件下达到当今Civic消耗量的一半,实现35km/L(日本10-15模式),3.4L/km(98/69/EC)的消耗量。为了达到这个目标,加入了许多用于包装和集成发动机辅助系统以及改善发动机效率的新技术,开发了一种新的集成式发动机辅助混合动力发动机系统。这是结合了一种低空气阻力的新型轻稆车身开发的。环境性能目标也包括了低排放(日本2000年标准的一半,EU2000标准的一半),高效率和杨回收性。对消费的关键特性全面考虑,包括碰撞安全性能,操纵性和运行特性。1 绪论为减小汽车对社会和环境的冲击要求其更干净并且能量效率更高更节能,空气质量更好。降低CO2排放问题作为全球环境焦点提出,解决这些问题的方法之一就是混合动力汽车。Honda已开发并向遍及全球的几大市场输入Insight,新一代车辆设计。 Insight将混合动力系与先进的车身技术特性相结合以符合取得实际的最高燃油经济性的总目标。混合动力系是发动机的辅助并联平行结构,把IMA叫做集成式发动机辅助。此动力系将把一个高效电动机与一个新型小排量VTEC发动机结合起来,很轻的铝车身,改良的空气动力学以实现3.4L/100km(CO2:80g/km)98/69/EC燃油经济性。低排放性能也已达到EU排放水平为目标。除减速能的重用之外,集成式发动机在典型的市区行驶加速时提供大助力扭矩,显著地减小了发动机损失,提高了发动机效率。接近56kW每吨的功率/质量比保证了稳定的爬坡能力和高速的常速行驶能力。新发动机技术包括促进高效快速的催化剂活性化的一种新VTEC(电子控制可变配气相位和气门升程)缸盖设计,促进稀薄燃烧能降低排放的新型稀NOx催化转化器,广泛的减摩及减重特色也用于其中。 2 开发目标及开发理念开发目的在于达到极低燃油消耗量。我们定
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