12吨摆臂式自卸汽车改装设计【说明书+CAD】
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南京理工大学泰州科技学院毕业设计(论文)外文资料翻译系系部：部： 机械工程 专专 业：业： 机械工程及自动化 姓姓 名：名： 吴炜 学学 号：号： 05010140 外文出处：外文出处： 附附 件：件： 1.外文资料翻译译文；2.外文原文。 指导教师评语： 签名： (用外文写) 年 月 日注：注：请将该封面与附件装订成册。附件附件 1 1：外文资料翻译译文：外文资料翻译译文黏性连接器用作前轮驱动时限制滑移对汽车牵引和操纵的影响1 基本概念黏性连接器主要地被认为是在四轮驱动的汽车上驱动路线的部件。然而在近些年的发展中，在主流的前轮驱动设备中这种装置将成为主要角色，这个观点是有可能的。在欧洲和日本前轮驱动轿车产量的施用已经证明黏性连接器不仅对于光滑路面的汽车牵引，而且在正常行驶条件下对于操纵性和稳定性都有所改善。这篇文章展现了一系列地面测试试验，显示黏性连接器对前轮驱动汽车牵引和操纵的影响。试验证明仅有轻微转向扭转的时候，牵引力才会改善。前轮驱动的汽车在直线行驶时，影响发动机转矩的因素被确定出来。确定关键汽车设计参数，对前轮驱动的汽车的限制滑移差速器适合性有极大地影响。转弯试验展现出黏性连接器在前轮驱动的汽车上独立转弯时的影响。进一步的试验证明安装黏性限制滑移差速器的汽车在加速和转弯时节气门频繁关闭的情况下显示出一个理想的稳定性。2 黏性连接器 黏性连接器被广泛认为是驱动列车的组成部件。在这篇文章中仅仅给出它的基本功能和原理的简明概要。黏性连接器是根据液体摩擦的原理和依靠速度差来运转的。正如图 1 所示黏性连接器的滑动控制特性和驱动观察系统的对比。这表明传送到前轮的驱动扭转力是由一个优化的扭转力分配检测器自动控制的。在前轮驱动的汽车上黏性连接器可以安装在差速器的内侧或者一根中间轴的外面。内部的这种设计方式有很大的优点。首先，在中间轴区域可以得到足够的空间来提供符合要求的黏性特性。这和当今前轮轴差速器只留下有限的空间相对比。其次，差速器架和转送轴套只需要很小的修改。而且差速器壳体的生产也仅仅只有一点影响。引用作为一个选择性的事很容易做到尤其当轴和黏性单元作为一个整体单元被共给时。最后，中间轴使为等长的的侧偏轴提供横向安装发动机是可能的，横向地安装发动机对于减小扭转力的操纵是很重要的（后面第四部分说明了） 。这种特殊的设计也为有实际意义的重量和黏性单元费用的降低给出了很好的可能性。GKN Viscodrive 正在发展一种低重量和低成本的黏性连接器。通过使用仅仅两个标准化的直径、标准化的盘，塑料轮毂和挤压成型的材料造成的储存室它能很容易地被截成不同的长度，使用一个宽的黏性范围是可能的。在图 3 中显示出这种发展的一个例子。3 牵引力的影响作为一个扭转力平衡装置，一个开的差速器提供相等的力到两个驱动轮上。它也允许每个车轮在扭转没结束转弯时以不同的速度转动。然而，这种特性当道路表面滑动系数为限制扭转力传递到两轮的左、右附着变动时是不利的，它能被低滑动系数的轮子支持。安装黏性限制滑移差速器,在高的值的路面上它可能利用高车轮潜在性的附着。例如，当一个车轮传递的最大扭转力超出表面滑动系数允许值或者以一个高的侧面加速度转弯时，两个车轮的速度是不同的.在黏性连接器中产生的自锁扭转力抵抗速度差的增加并且传递合适的扭转力到车轮上它具有更好的牵引力潜能。可以看出牵引力的不同导致汽车瞬间向低滑动系数值()一侧跑偏，为了保持汽车直线行驶驾驶员必须施加一个相反的扭转力来补偿。通过黏性连接器的液体摩擦原理和从打开到锁死柔和的传递结果,这是很可能的。报告称平均操纵轮扭转力和为保持带有一个开式的并且黏性的差速器在加ST速期间在滑动系数的路面上直线行驶应输入的平均正确的相对的转向操纵。相互对照开式差速器和那些黏性连接器是相对大的。然而，在绝对条件下它们是小的。主观地说，转向装置的影响是不明显的。扭转力操纵也受几个运动参数影响这些参数将在这篇文章下个部分解释。4 影响转向装置扭转力的因素 牵引力引起一个从头到尾的增加来反应每个车轮。因为带有限制滑动差速器的车轮在滑动系数的路面上加速时会出现不同的牵引力，所以从头到尾反应每个车轮的变化也是不同的。不幸的是，这个作用将导致一个不期望的朝低滑动系数一侧的反应，也就是说在不同的牵引力下产生相同的跑偏方向。降低从头到尾的弹力是黏性限制滑动差速器像其它任何形式差速器一样在前轴的成功应用所必须具备的。普遍地用下面的公式计算一个车轮的驱动力TVFF 牵引力TF车轮垂直载荷VF利用的附着系数这些驱动力导致在车轮之间每个车轮的转向装置扭转力经过车轮干扰常数 e干扰后与每个车轮的转向装置扭转力是不同的，给出下面的等式。cos()ioeH hH lTeFF 这里 扭转力矩差值eT e车轮干扰常数 主销倾角高滑动系数一侧下标ih低滑动系数一侧下标ol 在带有开式差速器前轮驱动汽车的情况下，是很不明显的，因为扭转力基ST数是不大于 1.35 的。(/)H hiH loFF然而，因为应用了限制滑动差速器，这个影响是很有意义的。这样车轮干扰常数 e 就应该尽可能的小。不同的车轮载荷也会导致的增加所以差别也要尽eTAeTA可能的小。当扭转力通过铰接“CV 连接”传递时，在主动一侧（下标 1）和从动一侧（下标 2） ，必须反应垂直平面相对于连接平面的不同的第二个力矩产生了。第二个力矩（M）大小和方向用于下面的式子计算：主动一侧12tan(/2)/tanvvMTTA从动一侧 22tan(/2)/tanvvMTTA2TdynTF rA2(,Tf T连接系统）这里 纵向连接角v 产生的连接角 产生变化的轮子半径dynr平均扭转力矩损失T当每个装置的转向扭转力以及轮子之间的转向装置扭转力不同时，将围绕着主销轴线变动，如下所示：2cosMAcosT 22(tan/2/sin)(tan/2/tan)vvw hivvw liTTTT这里 转向装置扭转力矩差T W轮子一侧的下标因此很明显不仅不同的驱动扭转力而且黏性驱动轴长度的不同也是一个因素。说道图 7 中的力矩多边形，的旋转方向或者各自地变化，都取决于轮子中心2MT到变速箱输出的位置。如图 7 所示由于半轴的正常位置（轮子中心低于变速箱的输出点）第二个力矩产生和驱动力一样的旋转方向。由于改进的悬挂装置设计（车轮中心高于变速箱输出点，也就是说，为负值）第二个力矩抵消了由驱动力引起的力矩。这样v为了得到带一个限制滑动差速器前轴好的适应性，设计要求：1）纵向弯曲角近似或者负值（）且左侧和右侧的值相等；2）等长度的侧轴。0v0vv第二力矩在转向装置的影响不仅仅是上面描述的限制直接反应。从连接轴到车轮侧面和变速箱侧面之间的连接点间接反应也会产生，如下所示：由纵向平面的半轴连接产生的间接反应因为扭转力传递没有损失并且两个在连接轴上的第二个力矩都相互vwvd补偿。然而，事实上（有扭转力损失） ，第二个力矩出现不同： 21DWDWMMM 22DWTTT第二个力矩不同点是：22()tan/2/sintan/2/tanDWWWVDWvwWvwMTTTTT为了简化应用给出和fTVDVWVDTT wT(tan/2 1/sin1/tan)DWvvvMTA需要在两个连接处都有抵抗反应的力这里DWM。由连接处引起的干扰常数 f，一个附加的转向装置扭转力矩也围/DWDWFML 绕着主销轴线变动： cos/fDWTMfL A A这里 每个车轮的转向装置扭转力矩fT 转向装置扭转力矩差fT f连接处干扰系数 L连接轴（半轴）的长度由于 f 值小，理想值是 0，的影响较小。fT5 转弯时的效应扭转时由于驱动轮的速度不相等，黏性连接器也提供一个自琐的扭转力矩。在平稳转向过程中，速度较慢的内侧车轮被外侧车轮黏性连接器施加的一个附加的驱动力。前轮驱动力的汽车稳定状态下转向时的牵引力。不同的牵引力和导致一个侧偏力矩 MCOG，它必须被一个较大的侧偏flDfrDflD力补偿，因此在前轴有一个大的滑动角 af。因此前驱动轮的汽车自动转向装置上黏性连接器的影响趋向一个在转向装置状态下的特性。这个运动方式整体上和所有转向操纵下在稳定状态下转弯移动时的现代汽车操纵方式的偏重心相一致.合适的试验结果如图表 11 所示。安装有开式差速器的汽车饿安装有黏性连接器的汽车在稳定状态下转弯时的对比所示在转弯时不对称的牵引力干扰也会改进汽车的直线行驶。每一次偏离正常的直线方向都会引起车轮以轻微的不同半径滚动。驱动力和产生的侧偏力矩差会使汽车重新回到直线行驶。虽然这些方向的偏离引起仅仅很小的车轮滚动半径差，但是旋转的偏差尤其在高速时对于一个黏性连接器前差速器是足够将汽车带到直线上行驶的。安装有开式差速器的高动力前轮驱动汽车当以低档加速离开紧急转角时通常旋转它们的内侧车轮。安装有限制滑动黏性差速器，这个旋转是有限的并且有不同车轮的速度差产生的扭转力为外侧的驱动轮提供附加的牵引力效果。装有黏性限制滑动差速器的前轮驱动汽车在转道上加速时的牵引力特别地当行驶或加速离开一个 T 形交叉路口加速能力就这样被改善（也就是说在 T 形路口横切向右或向左从停止位置加速） 。显示了装有开式差速器和装有黏性限制滑动差速器在稳定状态下转弯过程中加速试验的结果。装有一个开式差速器的前轮驱动汽车在半径为 40m 的湿沥青弯曲路面上加速特性（实验过程中安装有转向装置轮角测试仪）装有一个黏性连接器的前轮驱动汽车在半径为 40m 的湿沥青弯曲路面上加速特性（实验过程中安装有转向装置轮角测试仪）安装有一个开式差速器的汽车平均加速度为同时装有黏性连接CSDM22.0/m s器的汽车平均加速度达到（被发动机功率限制） 。在这些试验中，由内侧22.3/m s的从动轮引起的最大速度差，被从带有开式差速器的 240rpm 减少到带有黏性连接器的 100rpm。在弯道上加速行驶时，前轮驱动的汽车通常处在操纵状态下要多于其匀速行驶的状态。前轮传递侧偏力潜能降低的原理是由于重心移到后轴车轮并且在驱动轮上增加了纵向力。在一个开式环形控制循环测试中这个能够看出在开始加速以后（时间为 0 在图表 13 和 14 中）偏跑速度（跑偏率）的降低。从图表 13 和 14中还可以看出开始加速时装有开式差速器汽车的跑偏率比装有黏性连接器汽车的下降的更快。然而，在开始加速大约 2 秒后，黏性连接的汽车的跑偏率下降斜率增加高于装有开式差速器 的汽车。安装有限制滑动前差速器的汽车在转弯过程中加速时具有一个更稳定的最初反应比装有开式差速器的汽车，降低它的操纵状态。这是因为内侧驱动轮的高滑动通过黏性连接器产生一个增加的驱动力到外侧车轮。前轮牵引力的不平衡导致在行驶方向上的偏跑力矩，反对操纵状态。CSDM当驱动轮的附着限制是超出的,安装黏性连接器的汽车处于操纵状态比安装有开式差速器的汽车更明显(这里,开始加速后 2 秒)。在非常低的摩擦力表面，例如雪或者冰，当装有限制滑动差速器的汽车在曲线路面上加速时更强的操纵性被期望因为通过黏性连接器连接的驱动轮更容易旋转（动力转向装置） 。然而，这个特性能很容易地被驾驶员或者自动节气门调节牵引系统控制。在这些情况下比后轮驱动的汽车更容易控制。在转弯过程中当加速时它能够防止动力过分操纵。考虑到，所有的情况，装配有一个黏性连接器的汽车在加速过程中具有稳定的加速行动方式在光滑路面上只有小的缺点。通过突然释放加速器，在转弯过程中节气门关闭的反应，通常导致前轮驱动的汽车改换方向（节气门关闭超出了操纵） 。高动力的模型能得到高侧偏加速度显示出最大规模的反应。这个节气门关闭反应有几个原因例如运动学上的影响，或者，当汽车降低速度试着以一个较小的转变半径通过时。然而，实质上的原因，是动力的重心从后轴转移到前轴，这会导致前轴降低滑动角。后轴增加滑动角。因为，后轴车轮不传递驱动力矩，在这种情况下在后轴上的影响比前轴上的影响更大。在节气门关闭之前。 。安装有黏性限制滑动差速器前轮驱动的汽车当转变时关闭节气门后移动立刻产生的制动力随着内侧的车轮继续比外侧车轮更慢的转动，黏性联结器给外侧车轮提供更大的制动力。由于前轮力的不同围绕着汽车重量的中心会产生一个抵消正常fB转向反应的侧偏力矩 MCOG.。将安装有开式差速器的汽车和装有黏性联结器的在关闭节气门的移动过程中转向方式进行比较时，如图表 16 和 17 所示，安装有黏性差速器的两个驱动轮子之间速度差是降低的。在转弯半径为 40 米（不封闭的环形）的湿沥青路面上安装有开式差速器前轮驱动汽车的节气门关闭特性在转弯半径为 40 米（不封闭的环形）的湿沥青路面上安装有黏性联结器前轮驱动汽车的节气门关闭特性安装有开式差速器的汽车侧偏速度（侧偏率） ，和相对的侧偏角（除汽车保持继续在稳定状态下转弯的侧偏角之外）在节气门关闭后（时间为零如图表 14 和15）显示一个非常明显的增加。在安装有一个黏性的限制滑动差速器的汽车上节气门关闭后侧偏率的突然增加和相对侧偏角的增加都有很大的降低。例如在一个弯道上随着半径的增加，一上正常的驾驶一个超大号的前轮驱动汽车的人通常仅仅的惯常的空档的操纵装置下的汽车操纵方式，然后驾驶员忽然惊奇并且在节气门突然的释放后会有有力的操纵反应。如果驾驶员对情况的反应不正确汽车将进一步恶化汽车离开车道到曲线的内侧的事故是这个事件的验证。因此黏性联结器为一个正常的驾驶员改善节气门关闭的行为方式当保持可控制，可预言的并且安全驾驶时。7 总结总之，黏性联结器在前轴差速器的试用能被证实。它也明确地影响整个汽车的控制和稳定，只是稍微地，但是可以接受的在扭转力操纵上的影响。为了减小不想要的扭转力操纵的影响一个基本的设计准则被给出：1 由于纵向载荷改变产生的警觉反应必须尽可能的小2 主销轴线和车轮中心之间的距离必须尽可能的小3 垂直弯曲角变化范围应该接近零（或者为负值）4 两侧的垂直弯曲角应该一样5 侧轴应该等长扭转力操纵上最小影响是联结处干扰常数的理想值为零。带有和不带有 ABS制动，仅对黏性联结器仅有轻微的影响。在前轮驱动的汽车上，黏性限制滑动差速器显著提高了牵引力。有独立转向装置的前轮驱动汽车，在转向时会轻微影响黏性限制滑动差速器。前轴安装有黏性联结器的汽车，在转弯过程中关闭气门和改进加速的措施，使汽车更稳定而且更安全。附件附件 2 2：外文原文：外文原文The Effect of a Viscous Coupling Used as a Front-Wheel Drive Limited-Slip Differential on Vehicle Traction and Handling 1 ABCTRACTThe viscous coupling is known mainly as a driveline component in four wheel drive vehicles. Developments in recent years, however, point toward the probability that this device will become a major player in mainstream front-wheel drive application. Production application in European and Japanese front-wheel drive cars have demonstrated that viscous couplings provide substantial improvements not only in traction on slippery surfaces but also in handing and stability even under normal driving conditions.This paper presents a serious of proving ground tests which investigate the effects of a viscous coupling in a front-wheel drive vehicle on traction and handing. Testing demonstrates substantial traction improvements while only slightly influencing steering torque. Factors affecting this steering torque in front-wheel drive vehicles during straight line driving are described. Key vehicle design parameters are identified which greatly influence the compatibility of limited-slip differentials in front-wheel drive vehicles.Cornering tests show the influence of the viscous coupling on the self steering behavior of a front-wheel drive vehicle. Further testing demonstrates that a vehicle with a viscous limited-slip differential exhibits an improved stability under acceleration and throttle-off maneuvers during cornering.2 THE VISCOUS COUPLINGThe viscous coupling is a well known component in drivetrains. In this paper only a short summary of its basic function and principle shall be given.The viscous coupling operates according to the principle of fluid friction, and is thus dependent on speed difference. As shown in Figure 1 the viscous coupling has slip controlling properties in contrast to torque sensing systems.This means that the drive torque which is transmitted to the front wheels is automatically controlled in the sense of an optimized torque distribution.In a front-wheel drive vehicle the viscous coupling can be installed inside the differential or externally on an intermediate shaft.This layout has some significant advantages over the internal solution. First, there is usually enough space available in the area of the intermediate shaft to provide the required viscous characteristic. This is in contrast to the limited space left in todays front-axle differentials. Further, only minimal modification to the differential carrier and transmission case is required. In-house production of differentials is thus only slightly affected. Introduction as an option can be made easily especially when the shaft and the viscous unit is supplied as a complete unit. Finally, the intermediate shaft makes it possible to provide for sideshafts of equal length with transversely installed engines which are important to reduce torque steer.This special design also gives a good possibility for significant weight and cost reductions of the viscous unit. GKN Viscodrive is developing a low weight and cost viscous coupling. By using only two standardized outer diameters, standardized plates, plastic hubs and extruded material for the housing which can easily be cut to different lengths, it is possible to utilize a wide range of viscous characteristics.3 TRACTION EFFECTSAs a torque balancing device, an open differential provides equal tractive effort to both driving wheels. It allows each wheel to rotate at different speeds during cornering without torsional wind-up. These characteristics, however, can be disadvantageous when adhesion variations between the left and right sides of the road surface (split-) limits the torque transmitted for both wheels to that which can be supported by the low- wheel.With a viscous limited-slip differential, it is possible to utilize the higher adhesion potential of the wheel on the high-surface.When for example, the maximum transmittable torque for one wheel is exceeded on a split-surface or during cornering with high lateral acceleration, a speed difference between the two driving wheels occurs. The resulting self-locking torque in the viscous coupling resists any further increase in speed difference and transmits the appropriate torque to the wheel with the better traction potential.It can be seen in Figure 4 that the difference in the tractive forces results in a yawing moment which tries to turn the vehicle in to the low-side, To keep the vehicle in a straight line the driver has to compensate this with opposite steering input. Though the fluid-friction principle of the viscous coupling and the resulting soft transition from open to locking action, this is easily possible.Reported are the average steering-wheel torque Ts and the average corrective opposite steering input required to maintain a straight course during acceleration on a split-track with an open and a viscous differential. The differences between the values with the open differential and those with the viscous coupling are relatively large in comparison to each other. However, they are small in absolute terms. Subjectively, the steering influence is nearly unnoticeable. The torque steer is also influenced by several kinematic parameters which will be explained in the next section of this paper.5EFFECT ON CORNERINGViscous couplings also provide a self-locking torque when cornering, due to speed differences between the driving wheels. During steady state cornering, as shown in figure 10, the slower inside wheel tends to be additionally driven through the viscous coupling by the outside wheel.Tractive forces for a front-wheel drive vehicle during steady state cornering The difference between the Tractive forces Dfr and Dfl results in a yaw moment MCOG, which has to be compensated by a higher lateral force, and hence a larger slip angle af at the front axle. Thus the influence of a viscous coupling in a front-wheel drive vehicle on self-steering tends towards an understeering characteristic. This behavior is totally consistent with the handling bias of modern vehicles which all under steer during steady state cornering maneuvers. Appropriate test results are shown in figure 11.Figure 11: comparison between vehicles fitted with an open differential and viscous coupling during steady state cornering.The asymmetric distribution of the tractive forces during cornering as shown in figure 10 improves also the straight-line running. Every deviation from the straight-line position causes the wheels to roll on slightly different radii. The difference between the driving forces and the resulting yaw moment tries to restore the vehicle to straight-line running again.Although these directional deviations result in only small differences in wheel travel radii, the rotational differences especially at high speeds are large enough for a viscous coupling front differential to bring improvements in straight-line running.High powered front-wheel drive vehicles fitted with open differentials often spin their inside wheels when accelerating out of tight corners in low gear. In vehicles fitted with limited-slip viscous differentials, this spinning is limited and the torque generated by the speed difference between the wheels provides additional tractive effort for the outside driving wheel.Tractate forces for a front-wheel drive vehicle with viscous limited-slip differential during acceleration in a bend The acceleration capacity is thus improved, particularly when turning or accelerating out of a T-junction maneuver (i.e. accelerating from a stopped position at a “T” intersection-right or left turn).the results of acceleration tests during steady state cornering with an open differential and with viscous limited-slip differential.Accelerations characteristic for a front-wheel drive vehicle with an open differential on wet asphalt at a radius of 40m (fixed steering wheel angle throughout test).Acceleration Characteristics for a Front-Wheel Drive Vehicle with Viscous Coupling on Wet Asphalt at a Radius of 40m (Fixed steering wheel angle throughout test)The vehicle with an open differential achieves an average acceleration of 2.0 2/smwhile thevehicle with the viscous coupling reaches an average of 2.3 (limited by 2/smengine-power). In these tests, the maximum speed difference, caused by spinning of the inside driven wheel was reduced from 240 rpm with open differential to 100 rpm with the viscous coupling.During acceleration in a bend, front-wheel drive vehicles in general tend to understeer more than when running at a steady speed. The reason for this is the reduction of the potential to transmit lateral forces at the front-tires due to weight transfer to the rear wheels and increased longitudinal forces at the driving wheels. In an open loop control-circle-test this can be seen in the drop of the yawing speed (yaw rate) after starting to accelerate (Time 0 in Figure 13 and 14). It can also be taken from Figure 13 and Figure 14 that the yaw rate of the vehicle with the open differential falls-off more rapidly than for the vehicle with the viscous coupling starting to accelerate. Approximately 2 seconds after starting to accelerate, however, the yaw rate fall-off gradient of the viscous-coupled vehicle increases more than at the vehicle with open differential.The vehicle with the limited slip front differential thus has a more stable initial reaction under accelerating during cornering than the vehicle with the open differential, reducing its understeer. This is due to the higher slip at the inside driving wheel causing an increase in driving force through the viscous coupling to the outside wheel. The imbalance in the front wheel tractive forces results in a yaw moment acting in CSDMdirection of the turn, countering the understeer.When the adhesion limits of the driving wheels are exceed, the vehicle with the viscous coupling understeers more noticeably than the vehicle with the open differential (here, 2 seconds after starting to accelerate). On very low friction surfaces, such as snow or ice, stronger understeer is to be expected when accelerating in a curve with a limited slip differential because the driving wheels-connected through the viscous coupling-can be made to spin more easily (power-under-steering). This characteristic can, however, be easily controlied by the driver or by an automatic throttle modulating traction control system. Under these conditions a much easier to control than a rear-wheel drive car. Which can exhibit power-oversteering when accelerating during cornering. All things, considered, the advantage through the stabilized acceleration behavior of a viscous coupling equipped vehicle during acceleration the small disadvantage on slippery surfaces.Throttle-off reactions during cornering, caused by releasing the accelerator suddenly, usually result in a front-wheel drive vehicle turning into the turn (throttle-off oversteering ). High-powered modeles which can reach high lateral accelerations show the heaviest reactions. This throttle-off reaction has several causes such as kinematic influence, or as the vehicle attempting to travel on a smaller cornering radius with reducing speed. The essential reason, however, is the dynamic weight transfer from the rear to the front axle, which results in reduced slip-angles on the front and increased slip-angles on the rear wheels. Because the rear wheels are not transmitting driving torque, the influence on the rear axle in this case is greater than that of the front axle. The driving forces on the front wheels before throttle-off (see Figure 10) become over running or braking forces afterwards.Baraking Forces for a Front-Wheel Drive Vehicle with Viscous Limited-Slip Differential Immediately after a Throttle-off Maneuver While CorneringAs the inner wheel continued to turn more slowly than the outer wheel, the viscous coupling provides the outer wheel with the larger braking force. The force difference fBbetween the front-wheels applied around the center of gravity of the vehicle causes a yaw moment that counteracts the normal turn-in reaction.GCM0When cornering behavior during a throttle-off maneuver is compared for vehicles with open differentials and viscous couplings, as shown in Figure 16 and 17, the speed difference between the two driving wheels is reduced with a viscous differential.Throttle-off Characteristics for a Front-Wheel Drive Vehicle with an open Differential on Wet Asphalt at a Radius of 40m (Open Loop)Throttle-off Characteristics for a Front-Wheel Drive Vehicle with Viscous Coupling on Wet Asphalt at a Radius of 40m (Open Loop)The yawing speed (yaw rate), and the relative yawing angle (in addition to the yaw angle which the vehicle would have maintained in case of continued steady state cornering) show a pronounced increase after throttle-off (Time=0 seconds in Figure 14 and 15) with the open differential. Both the sudden increase of the yaw rate after thrott
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