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越野车 车架 制动 系统 设计 CAD 原创

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四驱越野车车架及制动系统设计含6张CAD图-原创.zip,越野车,车架,制动,系统,设计,CAD,原创

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液压制动系统当踩下制动踏板，您希望该车辆停下。液压制动踏板控制两个部分。首先，在液压作用下，由于采用细小的软管或金属线因此不必占用很大的空间。其次，液压机构提供了一个很大的优势，由一个很小的力踩在制动踏板上，会产生很大的力作用于车轮上。制动踏板连接在充满制动液的制动液压缸的活塞上，液压缸由活塞和油箱组成。现代主缸其实是两个独立的腔体。这种结构称之为双回路系统，因为前腔连接到前制动器与后腔连接到后制动器。（有些车辆是对角连接）。两个腔实际是分离的，允许紧急制动时一个系统失效另一个系统起作用。整个液压系统是从主缸到车轮都充满制动液。当制动踏板放松时，活塞在总泵中移动，在整个液压回路中产生压力。回路中充满液压力，强制轮（鼓式制动器）或（盘式制动器）压迫制动蹄或制动盘。压力压迫制动蹄或制动片作用于制动鼓或制动盘最终是车辆停止。此外，制动踏板控制一个灯的开关，刹车灯的踏板放松时，开关回到正常位置而灯灭。每一个鼓式制动器包含两个活塞，二个并排放置，向相反方向推动施加制动力。盘式制动器中，轮缸都是制动钳（有的可能有多达4个或是1个 ）的一部分。所有活塞都使用某种类型的橡胶密封，防止液压液泄漏出活塞，以及用橡胶密封防尘或污垢和水分进入轮缸。当制动踏板被释放，弹簧推动总泵活塞移动到总泵活塞在正常位置。回流阀允许液体流向轮缸或流回制动总缸。当制动液流向制动轮缸，多余的液体回流，补偿已被活塞移动距离的液压油。液压油若泄露也由回油阀回流。所有双回路制动系统使用一个开关来激活，并监控液压油的压力。开关阀门位于警告位置安装在主缸主阀门附近。活塞每次从前回路和后回路之间循环。当结束制动是压力是平衡的，活塞位置是稳定的，但是当一个回路有泄漏，在更大的制动系统压力下将迫使偏向活塞一方或另一方，关闭开关，就启动警示灯. 点火开关起动发动机时或驻车制动时报警灯也是被激活的。前盘，后鼓制动系统也有一个计量阀，以防止前，后制动器有制动间隙。用以确保前盘式制动器一般不会单独使用，停止汽车。压力控制阀也可以用来限制压力，以防止在后轮制动中锁定。制动蹄和制动片使用相似材料。制动蹄或制动块由金属信号板和摩擦衬片组成。衬片是由粘结剂(被胶合)粘结或铆接的。通常，铆接的衬片效果比较好，但是粘结的衬片是更能充分表现摩擦材料的性能。摩擦材料在不同的制造商中生产是不同的，并且大致的类型可被分为：石棉类，有机类，半金属类，金属类。在不同的类型中成分和成分的百分比是不同的。一般来说，有机和非金属石棉化合物是常用的，容易在电子设备中有好的表现。但是对于高温操作来，他们可能不是您的耐用或山地驾驶的最佳的选择。在许多情况下，这些衬片将比有些金属化合物片更快速磨损，因此您经常得将替换他们。但是，当使用这些制动衬片时，电子设备将有更长的寿命。 半金属刹车片或金属化合物的表现因成分的不同而有所不同。一般来说，金属含量越高，性能越好，摩擦材料的散热性将越好。所以使它们更适合重型汽车使用，但是，金属和半金属为更容易发生啸叫，在大多数情况下，金属化合物比非金属片更容易发生啸叫。因此需要更经常更换衬片。当你想确定什么类型的刹车片是适合你，请记住，在今天现代汽车制动系统是汽车的预期相匹配的表现性能之一。原始设备制造商从规格材质到刹车材料感觉并不能给你提供帮助。所以在你改变刹车材料前，先谈谈你的零件供应商，以帮助决定什么是最适合您的刹车片。记住若你经常使用例如拖曳，停止并且频繁驾驶，行驶在山路和赛跑也许都对性能材料有更高的要求因此需要你经常更换刹车片。一些特殊的材料也用在刹车片中，其中有芳纶，碳材料。这些材料具有极其良好的刹车性能，山区驾驶或在赛场上驾驶都表现很好。耐磨性可能更胜于金属材料，而许多的其他性能更像非金属。附 录Hydraulic Brake SystemsWhen you step on the brake pedal,you expect the vehicle to stop.The brake pedal operates a hydraulic that is used for two reasons.First,fluid under pressure can be carried to all parts of the vehicle by small hoses or metal lines without taking up a lot of room of causing routing problems.Second,the hydraulic fluid offers a great mechanical advantage-little foot pressure is required on the pedal,but a great deal of pressure is generated at the wheels.The brake pedal is linked to a piston in the brake master cylinder containing a small piston and a fluid reservoir. Modern master cylinders are actually two separate cylinders.Such a system is called a dual circuit,because the front cylinder is connected to the front brakes and the rear cylinder to the rear brakes.(Some vehicles are connected diagonally).The two cylinders are actually separated,allowing for emergency stopping power should one part of the system fail. The entire hydraulic system from the master cylinder to the wheels is full of hydraulic brake fluid.When the brake pedal is depressed,the piston in the master cylinder are forced to move,exerting tremendous force on the fluid in the lines.The fluid has nowhere to go,and forces the wheel cylinder pistons(drum brakes) or caliper pistons(disc brakes) to exert pressure on the brake shoes or pads.The friction between the brake shoe and wheel drum or the brake pad and rotor (disc) slows the vehiche and eventually stops it. Also attached to the brake pedal si a switch that lights the brake lights as the pedal is depressed.The lights stay on until the brake pedal is released and returns to its normal position. Each wheel cylinder in a drum brake system contains two pistons,one at either end,which push outward in opposite directions.In disc brake systems,the wheel cylinders are part of the caliper (there can be as many as four or as few as one ).Whether disc or drum type,all pistons use some type of rubber seal to prevent leakage around the piston,and a rubber dust boot seals the outer of the wheel cylinders against dirt and moisture. When the brake pedal is released,a spring pushes the master cylinder pistons back to their normal positions.Check valves in the master cylinder piston allow fluid to flow toward the wheel cylinders or calipers as the piston returns.Then as the brake shoe return springs pull the brake shoes back to the released position,excess fluid returns to the master cylinder through compensating ports,which have been uncovered as the pistons move back.Any fluid that has leaked from the system will also be replaced through the compensating ports. All dual circuit brake systems use a switch to activate a light,warning of brake failure.The switch si located in a valve mounted near the master cylinder.A piston in the valve reveives pressure on each end from the front and rear brake circuits.When the pressures are balanced,the piston remains stationary,but when one circuit has a leak,greater pressure during the application of the brakes will force the piston to one side or the other,closing the switch and activating the warning light.The light can also be activated by the ignition switch during engine starting or by the parking brake. Front disc,rear drum brake systems also have a metering valve to prevent the front disc brakes from engaging before the rear brakes have contacted the drums.This ensures that the front brakes will not normally be used alone to stop the vehicle.A proportioning valve is also used to limit pressure to the rear brakes to prevent rear wheel lock-up during hard braking. Brake shoes and pads are constructed in a similar.The pad or shoe is composed of a metal backing plate and a priction lining.The lining is either bonded(glued) to the metal,or riveted.Generally,riveted linings provide superior performance,but good quality bonded linings are perfectly adequate.4ABSTRACTA drive train for a four wheel drive vehicle including a front difforential engaged with a front drive shaft and front axles through a front differential gear set. The front differential includes a front bi-directional overrunning clutch that controls transmission of torque transfer between the front drive shaft and the front axles. A rear differential is engaged with rear axles and the transmission through a rear differential gear set. The rear differential includes a rear bi-directional overrunning clutch that controls torque transfer between the transmission and the rear axles. The differentials are configured with a gear ratio that is within five percent of a l: 1 gear ratio.TRUE FOUR WHEEL DRIVE SYSTEM FOR VEHICLERELATED APPLICATIONThis application is related to and claims priority from U.S. Provisional Application 61/677,820, the disclosure of which is incorporated herein by reference in its entirety.FIELD OF THE INVENTIONThe invention relates to drive systems and, more particularly, to an improved drive system designed to provide substantially true four wheel drive capability.BACKGROUNDprovide four wheel drive capability. Those systems are all designed to engage all four wheels but also allow a speed differential across the axle. However, many of those systems do not provide true four wheel drive where each wheel provides substantially the same speed during all drive conditions. Instead, the systems permit some degree of slippage. Current Four Wheel Drive Bi-Directional Overrunning Clutch Systems I illustrates the drive system for a conventional four wheel drive vehicle with a front bi-directional overrul111ing clutch. The drive system includes four wheels. The rear left wheel RLW is connected to a rear differential RD through a rear left axle RLA. The right rear wheel RRW is com1ected to the rear differential RD through a rear right axle RRA. The front left wheel FLW is col111ected to a front differential FD through a front left axle FLA. The front right wheel FRW is connected to the front differential FD through a front right axle FRA.mission T through a rear drive shaft RDS. The front differential FD is connected to the transmission T through a front drive shaft EDS. Straight Line Operation: During straight line driving while the vehicle is in a four wheel on demand mode (i.e., four wheel drive engages only when needed) both rear wheels RLW, RRW are the primary drive wheels and are co1111ected through the rear differential RD to rotate at the same speed. In a non-slip condition of the rear wheels, the front drive shaft FDS is engaged to the front differential FD, but the front axles FLA, FRA are not engaged with the front differential. That is, the front axles FLA, FRA and front wheels FLW, FRW are generally in an overrun condition such that the front differential FD is not driving the front axles FLA, FRA and, therefore, not transmitting any torque to the front wheels. This means that the front wheels FLW. FRW are free to rotate at their actual ground speeds. In order for the front wheels to be engaged, the rear wheels must slip (break traction) or spin increase speed approximately 20% faster than the front wheels. While driving in a straight line, once the rear wheels slip 20%, the overrunning condition in the front differential ED is overcome and both front axles are engaged. This results in the transmission T transmitting torque to the front wheels thru the front drive which is geared in a way that decreases the vehicles ground speed. When the ground speed has increased so as to cause the rear wheel speed to be rotating less than 20% faster than the ground speed, or the speed of the rear wheel has decreased so as to be rotating less than 20% faster than the ground speed, the front wheels will start to overrun again and no torque will be transmitted to the front wheels. Turning Operation: In a comer all four wheels are trying to rotate at different speeds, This is shown on the chart in FIG. 4 which depicts wheel revolutions vs. turning radius for all four wheels. For a vehicle with alocked rear axle or solid axle (i.e., an axle where the rear axles RLA, RRA are connected, either physically or through gearing, such that they always rotate at the same speed) the ground speed is dictated by the rear outside wheel due to vehicle dynamics (i.e., the rear outside wheel has to cover more circumferential distance than the rear inside wheel when turning around a common axis.) Since both rear wheels are rotating at the same speed and the rear outside wheel is the drive wheel the rear inside wheel is beginuing to scrub or drag on the ground. This can cause inefficiencies, turf wear and/or tire wear. The primary reason conventional bi-directional ovemnming clutch four wheel drive systems have a 20% under drive is for turning. With the rear outside wheel dictating ground speed the front inside wheel will go slower than the rear outside wheel as shown in FIG. 4. If there is no under drive the bi-directional oveITllllling clutch for the front inside axle would engage and begin to drive torque. This would cause the front inside wheel to travel at an incorrect speed and would create inefficiencies, turf wear, tire wear and, more importantly, torque steer. As mentioned above, during a tum the rear outside wheel is dictating ground speed, the rear inside wheel is scrubbing or dragging, and the front wheels are overrunning. Referring to FIG. 5 which depicts the percentage difference between the front and rear wheel speeds versus the turning radius of a locked rear axle, once the rear outside wheel slips or spins a certain percentage, dictated by vehicle geometry and turning radius. the bi-directional overru1ming clutch controlling the transfer of torque to the front inside wheel will engage and drive torque through the front inside wheel At this time both rear wheels and the front inside wheel are driving torque and their speed is dictated by the drive line, not ground speed. The front outside wheel is still ovemmning allowing it to spin at the rotational speed dictated by ground speed and vehicle geometry. When both rear wheels and the front inside wheel slip a certain percentage, again dictated by vehicle geometry and the turning radius, the bidirectional clutch controlling torque transfer to the front outside wheel will engage and torque will be transmitted to all four wheels, even though three of the wheels would be slipping. Wedging The existing drive system is prone to a condition called wedging. Wedging occurs when torque is being driven through the bidirectional over-numing clutch and a rapid direction change occurs. This can cause the rollers in the clutch to be positioned or locked on the wrong side of the clutch profile preventing the output hubs from overru1ming. The effect causes the front drive to act like a solid axle, but with the 20% speed difference in the drive line it results in scrubbing of the front tires. This condition can cause excessive tire wear and turf wear. This also effects steering effort and stability of the vehicle. The vehicle will try to maintain a straight line due to the effect of the front drive acting like a solid axle.Because of the wedging condition in the current systems precautions are put into place to help reduce wedging. One of these precautions is the use of a cut-off switch so that when the vehicle is shifted from the forward direction to the reverse direction so as to automatically disengage the bi-directional overrum1ing clutch (for example, shutting off the coil that is indexing the roll cage). This system also uses the cut-off switch when transitioning from the reverse direction to the forward direction. Another way to reduce wedging is the use of a switch, when the brakes are applied, that will interrupt power to the 4 wheel drive system. Many other methods can be used to reduce wedging, but none are 100% percent effective with the 20% difference in drive line speeds. Conventional Drive Systems:A common conventional drive system would have the same vehicle layout as in FIG. 1, but the mechanisms in the front and rear differentials would be different. Most common drive systems have an open differential with the ability to be locked into a solid axle in both the front and rear differentials. The drive line in a conventional system would also be using a drive line that is geared to a 1: 1 ratioStraight Line Operation: During straight line driving while the vehicle is in four wheel drive and all the axles are unlocked, all four wheels are rotating at the same speed. This is due to the drive line being geared at 1:1 ratio and the front and rear differentials are being driven at the same speed and no differentiation is needed across the axles. This is also the case when any or both of the front and rear differentials are in a locked position creating a solid axle. Turning operation:Conventional four wheel drive systems will normally have the rear differential locked and the front drive will be in the open state until the solid axle mode is selected by the user. During turning with a solid axle in the rear differential and an open differential in the front, only one tire is turning at the correct ground speed. Due to vehicle dynamics the rear outside wheel is considered the drive wheel and is turning at ground speed. The inside rear wheel is being driven at the same speed as the rear outside, but the ground speed is slower. This causes the inside rear wheel to scrub or slip during a tum. (0023 Since the two front wheels are connected to an open differential, they are allowed to differentiate across the axle, However, the differential is being driven at an incorrect speed. That is, the front open differential takes the input speed and averages it across the axle. In a normal non slip condition the average speed across the axle is centered about the middle of he vehicle. Since the rear outside wheel is traveling at a different speed ( or arc) than the average of the two front wheels, both front wheels are scrubbing when in a tum causing un-needed drive line torque or drive line bind. Once the operator selects the solid axle mode of the vehicle, both front wheels are locked together and they now rotate at the same speed. When turning, the outside front wheel is going slower than what ground speed dictates, thus causing the wheel to scrub. At the same time the inside front wheel is going faster than the ground speed dictates causing it to, likewise, scrub. Due to the wheels being driven at the wrong speeds in a comer, conventional drive systems are not very efficient. They cause severe turf damage or wear due to the tires scrubbing. They also cause tire wear due to the scrubbing. The tires being driven at the wrong speeds also cause issues with steering and turning performance of the vehicle. The difference between ground and actual wheel speed results in the wheels trying to straighten the vehicle out. This causes increased wear in steering components, as well as rider fatigue since increased input is needed to maintain the vehicle in the tum. Many manufacturers have added power steering to try to minimize operator input when cornering because of the four wheel drive operations. A need therefore exists for an improved four wheel drive system that incorporates bi-directional overrunning clutches in a drive system that minimizes scrubbing in all wheels while permitting 1.1 or near 1: 1 gear ratio between the front and rear axles. SUMMARY OF THE INVENTIONThe present invention is directed to drive train for a four wheel drive vehicle. The drive train includes a front drive shaft connected to a transmission. Two front axles with each axle connected to a corresponding front wheel. A front differential is engaged with the front drive shaft and the front axles through a front differential gear set. The front differential includes a front bi-directional overrunning clutch that controls transmission of torque transfer between the front drive shaft and the front axles. The front bi-directional ovemmning clutch includes a front clutch housing connected to the front drive shaft so as to be rotatable by the front drive shaft, the front clutch housing including an inner cam surface. A front roller assembly is located inside the front clutch housing and adjacent to the cam surface. The front roller assembly includes a roll cage with a plurality of rollers arranged in two sets within slots formed in the roll cage, the rollers are rotatable inside the slots. A plurality of springs are arranged in the roll cage to position the rollers within the slots. The roll cage is rotatable within the front clutch housing. (0029 Two front hub are located in the front clutch housing. Each hub is positioned radially inward from a set of the rollers located between an outer surface of the front hub and the im1er cam surface. Each front hub is engaged with an axial end of one of the front axles so as to rotate in combination with the axle. The front hubs are independently rotatable within the roll cage and the front clutch housing. A front engagement control assembly is located within the housing and controls engagement and disengagement of the front bi-directional overrunning clutch. The front engagement control assembly includes an electromechanical device that is controllable for impeding rotation of the roll cage relative to the front clutch housing so as to index the roll cage relative to the front clutch housing. When the engagement control assembly is activated and the roll cage is indexed relative to the clutch housing, the front bi-directional overrunning clutch is configured to transmit torque from the front drive shaft to the front axles when the front clutch housing is rotating faster than the front axles. Also, when the vehicle is traveling straight the front differential is configured to begin to transmit torque from the front drive shaft to the front axles at a first speed. The gear train including two rear axles, each axle com1ected to a corresponding rear wheel. A rear differential is engaged with the rear axles and the transmission through a rear differential gear set. The rear differential including a rear differential housing and a rear bi-directional overrunning clutch that controls torque transfer between the transmission and the rear axles. The rear bi-directional overrunning clutch includes a rear clutch housing located within the rear differential !musing and rotatable by the transmission, the rear clutch housing including an inner cam surface. A rear roller assembly is located inside the rear clutch housing and adjacent to the cam surface. The rear roller assembly includes a roll cage with a plurality of rollers arranged in two sets within slots formed in the roll cage. The rollers are rotatable inside the slots. A plurality of springs are arranged so as to position the rollers within the slots. The roll cage is rotatable within the rear clutch housing. Two rear hubs are located in the rear clutch housing. Each hub is positioned radially inward from a set of the rollers located between an outer surface of the rear hub and the im1er cam surface. Each rear hub is engaged with an axial end of one of the rear axles so as to rotate in combination with the axle. The rear hubs are independently rotatable within the roll cage and the rear clutch housing.The rollers in each set of the rear roller assembly are adapted to wedgingly engage the corresponding rear hub to the rear clutch housing when one of either the rear hub or rear clutch housing is rotating faster than the other so as to transmit torque from whichever is faster to whichever is slower. The differentials are configured such that when the vehicle is traveling straight and the rear differential is transmitting torque to the rear axles. The rear differential is configured to rotate the rear axles at a second speed, and where the difference between the first speed and the second speed is five percent or less. In one preferred embodiment, the difference between the first speed and the second speed is less than about three percent. In another embodiment there is substantially no difference between the first speed and the second speed.In one embodiment, the front bi-directional overrunning clutch includes an armature plate that is engaged or connected with the front roll cage such that the armature plate rotates with the roll cage. The front engagement control assembly impedes rotation of the roll cage relative to the front clutch housing by engaging the amiature plate so as to index the roll cage relative to the clutch housing.Preferably the hubs are substantially coaxially aligned with each other within the housing. and are adapted to rotate about a common axis within the housing. In one embodiment, the rear differential is part of a transaxle which is engaged with the transmission. 。 In another embodiment the front differential is part of a transaxle which is engaged with the transmission. The foregoing and other features of the invention and advantages of the present invention will become more apparent in light of the following detailed description of the preferred embodiments, as illustrated in the accompanying figures. As will be realized, the invention is capable of modifications in various respects, all without departing from the invention. Accordingly, the drawings and the description are to be regarded as illustrative in nature, and not as restrictive.摘要一种用于四轮驱动车辆的传动系统，包括与前驱动轴接合的前差速器和通过前差速齿轮组的前轴。 前差速器包括前双向超越离合器，其控制前驱动轴和前轴之间的扭矩传递的传递。 后差速器通过后差速齿轮组与后轴和变速器接合。 后差速器包括控制变速器和后轴之间的扭矩传递的后双向超越离合器。差速器构造成具有百分之五内1：1的齿轮比误差比。真正的四轮驱动系统车辆相关申请本申请与美国临时申请61 / 677,820相关并要求其优先权，其公开内容通过引用整体并入本文。本发明涉及驱动系统，更具体地，涉及一种设计成提供基本上真实的四轮驱动能力的改进的驱动系统。背景提供四轮驱动能力。 这些系统都被设计成接合所有四个车轮，但也允许在车轴上有速度差。 然而，这些系统中的许多不提供真正的四轮驱动，其中每个轮在所有驱动条件期间提供基本相同的速度。 相反，系统允许一定程度的滑动。正确的四轮驱动双向超越离合器系统图1示出了用于具有前部双向超越离合器的常规四轮驱动车辆的驱动系统。 驱动系统包括四个轮子。 后左轮RLW通过后左轮轴RLA连接到后差速器RD。 右后轮RRW通过右后轮RRA连接到后差速器RD。 前左轮FLW通过左前车轴FLA与前差速器FD连接。 右前轮FRW经由右前轮FRA与前差速器FD连接。单元T通过后传动轴RDS。 前差速器FD通过前驱动轴EDS连接到变速器T.直线操作在车辆处于四轮按需模式（即，四轮驱动仅在需要时接合）的直线行驶期间，两个后轮RLW，RRW都是主驱动轮，并且通过后差速器RD联接以旋转 以相同的速度。 在后轮的防滑状态下，前驱动轴FDS接合到前差速器FD，但是前轴FLA，FRA不与前差速器接合。 也就是说，前轴FLA，FRA和前轮FLW，FRW通常处于超速状态，使得前差速器FD不驱动前轴FLA，FRA，因此不向前轮传递任何扭矩。 这意味着前轮FLW。 FRW可以以其实际地速度自由旋转。为了使前轮接合，后轮必须滑动（断开牵引）或旋转增加速度比前轮快大约20。 当在直线上行驶时，一旦后轮滑动20，则克服前差速器ED中的超速状况，并且两个前轴接合。 这导致变速器T通过以减小车辆地速的方式来使变速的前驱动器将扭矩传递到前轮。 当地速增加以致使后轮速度比地速的旋转小于20，或者后轮的速度已经减小以便比地速更快地旋转小于20时 ，前轮将再次开始超速，并且没有扭矩将被传递到前轮。转向操作：在角落中，所有四个轮子都试图以不同的速度旋转。这在图1中的图表上示出。 图4示出了所有四个车轮的车轮转数对转弯半径。 对于具有锁定的后轴或实心轴（即，其中后轴RLA，RRA被物理连接或通过齿轮连接，使得它们总是以相同的速度旋转的轴）的车辆，地速由后外侧 由于车辆动力学（即，当围绕公共轴线转动时，后外轮必须覆盖比后内轮更多的圆周距离）。由于两个后轮以相同的速度旋转，并且后外轮是驱动轮 后内侧轮开始在地面上擦洗或拖曳。 这可能导致效率低下，草皮磨损和/或轮胎磨损。主要原因是传统的双向四通离合器四轮驱动系统力的20%用于转向。 由于后外轮确定地速，前内轮将比后外轮慢，如图3所示。 如果没有低于驱动，用于前内轴的双向偏心离合器将接合并开始驱动扭矩。 这将导致前内侧车轮以不正确的速度行驶，并且将产生低效率，草皮磨损，轮胎磨损，并且更重要的是，扭矩转向。如上所述，在转弯期间，后外轮轮流地面速度，后内轮是擦洗或拖曳，并且前轮是超速的。参考图1。图5示出了一旦后外轮滑动或旋转一定百分比（由车辆几何形状和转弯半径决定）时，前后车轮速度相对于锁定后车轴的转动半径的百分比差异。控制到前内轮的转矩传递的双向超越离合器将接合并通过前内轮驱动转矩。此时，后轮和前内轮都是驱动转矩，并且它们的速度由驱动线决定，不是地速。前外轮仍然是超速的，允许其以由地速和车辆几何形状决定的旋转速度旋转。当两个后轮和前内轮滑动一定百分比，再次由车辆几何形状和转弯半径决定时，控制到前外轮的扭矩传递的双向离合器将接合，并且扭矩将被传递到所有四个车轮中，即使其中的三个车轮将滑动。楔入现有的驱动系统倾向于称为楔入的状态。 当扭矩通过双向超越离合器被驱动并且发生快速方向改变时，发生楔入。 这可能导致