资源描述
41附录Automobile differential deviceThe motor car engine power after the coupling, the transmission gearbox, the drive shaft, the final biography delivers driving axle about to assign again for semi axis actuates the wheel, in this transmission of power way, driving axle is last always becomes, its major component is the reduction gear and the differential device. The reduction gear function is decelerates increases rectangular, this function depends entirely on between the gear and the gear meshes completes, compared with is easy to understand. But the differential device quite is difficult to understand that, what is called the differential device, why wants “the difference fast“?The automobile differential device is actuation host. Its function is while to two side semi axis transmissions powers, allows nearby two semi axis to revolve by the different rotational speed, satisfies two side wheels to the form which purely rolls not to make same lengge the travel as far as possible, reduces the tire and the ground friction.automobile when the corner the wheel trajectoryis a circular arc, if the automobile ten left is curved, the circular arc central point in left side, in the same time, the arc which right flank the wheel walks compared to a left side turn of Zichang, in order to balance this difference left side, wants wheel slow, right side wheel quick, makes up the distance with the different rotational speed the difference.If back wheel makes a whole, is unable to achieve two sides wheels the rotational speed difference, also is cannot achieve the automatic control. In order to solve this problem, 42as early as in 100 years ago, French Reynold car companys founder Louis Reynold designed the differential device this gadget ordinary differential device by the planet gear, planetary gear, components and so on rear axle shaft gear has been composed. The engine power classics and commentaries moving axis enters the differential device, the direct drive planetary gear frame, leads left, right two again by the planetary gear semi axis, separately actuates left, the right wheel. The differential device design request satisfies: (leftsemi axis rotational speed) (rightsemi axis rotational speed) =2 (planetary gear rotational speed). When automobile go alone, is left, the right wheel and a planetary gear three rotational speed equally is at the state of equilibrium, but when automobile curve three states of equilibrium are destroyed, cause an inside turn of rotational speed to reduce, a flank turn of rotational speed increases.This kind of adjustment is automatic, here involves “the smallest energy consumption principle“, also is on the Earth all objects all favors to consumes energy the smallest condition. For example admits a grain of bean in a bowl, the bean can automatically pause in the bowl bottom but cannot pause in the bowl wall, because the bowl bottom is the energy lowest position (potential energy), its automatic selection static (kinetic energy is smallest) but cannot the unceasing movement. Similar truth, wheel when curve also can automatically tend to the energy consumption lowest condition about, when automatically adjusts a turn of rotational speed.works as the curve according to the radius of turn, because outside side wheel has the phenomenon which slippery tows, in side wheel has wheelspin the phenomenon, two driving gears this time can opposite have two directions to attach the thrust augmentation, because “the smallest energy consumption principle“, inevitably causes two side wheels the rotational speeds to be different, thus destroyed three balances relations, 43and through semi axis reflected to the rear axle shaft gear on, forces the planet gear to have the rotation, makes the flank semi axis rotational speed to speed up, the inside semi axis rotational speed reduces speed, Thus realizes two sidecars turn of rotational speeds difference.On the automobile uses the gear drive the part to have driving axle, the transmission gearbox, the engine, the azimuth training gear and so on always becomes, the different part uses a form different size not gear. In all kinds of gear, some one name named “the hyperbolic curve“ the gear, matches in the market in the steam also to have specially uses in its lubricating oil to be called “the hyperbolic curve gear oil“. This kind of gear uses on the driving axle main gear box.On the passenger vehicle main gear box generally uses the hyperbolic curve gear. This is because the hyperbolic curve gear compares with the spiral bevel gear, former revolution noise few, work steadier, turns the tooth intensity to be higher, moreover also has the drive gear spool thread to be allowed the relative driven gear disalignment characteristic, this point regarding the，automobile technical performance count for much, engineer to be allowed in not to change the engine the position size to be allowed directly to change driving axle the ground clearance, also is changes the entire vehicle the ground clearance.Some automobiles produce the passenger vehicle and the movement leisure vehicle on the identical frame, its chassis parameter transformation also has used hyperbolic curve gear this characteristic. Because has these merits, at present automobile driving axle already tended to uses the hyperbolic curve gear, in fact recent years imported the automobile basically was uses the hyperbolic curve gear, the domestically produced automobile also has many vehicle types to use the hyperbolic curve gear, and already more and more many in center, on the heavy freight vehicle obtained uses.when the hyperbolic 44curve gear worked, between the tooth face can have in a big way relatively skids, also the tooth face pressure was very big, the tooth face lubricant film is easily destroyed. In order to reduce the friction, enhances the efficiency, must have to use includes guards against blows the wound chemical additive special-purpose hyperbolic curve gear oil, cannot use other gear oil to replace, otherwise will cause the tooth face rapid attrition and the abrasion, seriously will affect the automobile the running status.汽车的差速器汽车发动机的动力经离合器、变速器、传动轴，最后传送到驱动桥再左右分配给半轴驱动车轮，在这条动力传送途径上，驱动桥是最后一个总成，它的主要部件是减速器和差速器。减速器的作用就是减速增矩，这个功能完全靠齿轮与齿轮之间的啮合完成，比较容易理解。而差速器就比较难理解，什么叫差速器，为什么要“差速”？汽车差速器是驱动轿的主件。它的作用就是在向两边半轴传递动力的同时，允许两边半轴以不同的转速旋转，满足两边车轮尽可能以纯滚动的形式作不等距行驶，减少轮胎与地面的摩擦。汽车在拐弯时车轮的轨线是圆弧，如果汽车向左转弯，圆弧的中心点在左侧，在相同的时间里，右侧轮子走的弧线比左侧轮子长，为了平衡这个差异，就要左边轮子慢一点，右边轮子快一点，用不同的转速来弥补距离的差异。如果后轮轴做成一个整体，就无法做到两侧轮子的转速差异，也就是做不到自动调整。为了解决这个问题，早在一百年前，法国雷诺汽车公司的创始人路易斯.雷诺就设计出了差速器这个玩意。普通差速器由行星齿轮、行星轮架（差速器壳）、半轴齿轮等零件组成。发动机的动力经传动轴进入差速器，直接驱动行星轮架，再由行星轮带动左、右两条半轴，分别驱动左、右车轮。差速器的设计要求满足：（左半轴转速）+（右半轴转速）=2（行星轮架转速）。当汽车直行时，左、右车轮与行星轮架三者的转速相等处于平衡状态，而在汽车转弯时三者平衡状态被破坏，导致内侧轮转速减小，外侧轮转速增加。这种调整是自动的，这里涉及到“最小能耗原理”，也就是地球上所有物体都倾向于耗能最小的状态。例如把一粒豆子放进一个碗内，豆子会自动停留在碗底而绝不会停留在碗壁，因为碗底是能量最低的位置（位能），它自动选择静止（动能最小）而不会不断运动。同样的道理，车轮在转弯时也会自动趋向能耗最低的状态，自动地按照转弯半径调整左右轮的转速。当转弯时，由于外侧轮有滑拖的现象，内侧轮有滑转的现象，两个驱动轮此时就会产生两个方向相反的附加力，由于“最小能耗原理”，必然导致两边车轮的转速不同，从而破坏了三者的平衡关系，并通过半轴反映到半轴齿轮上，迫使行星齿轮产生自转，使外侧半轴转速加快，内侧半轴转速减慢，从而实现两边车轮转速的差异。汽45车上用到齿轮传动的部件有驱动桥、变速器、发动机、方向机等总成，不同的部件采用形式不同大小不一的齿轮。在各式各样的齿轮中，有一种名叫“双曲线”的齿轮，在汽配市场上还有专门用于它的润滑油叫做“双曲线齿轮油”。这种齿轮用在驱动桥的主减速器上。轿车上的主减速器一般采用双曲线齿轮。这是因为双曲线齿轮与螺旋锥齿轮比较，前者运转噪音少，工作更平稳，轮齿强度较高，而且还具有主动齿轮轴线可以相对从动齿轮轴线偏移的特点，这一点对于汽车的技术性能非常重要，工程师可以在不改变发动机的位置尺寸就可以直接改变驱动桥的离地间隙，也就是改变整部车的离地间隙。有些汽车在同一车架上生产轿车和运动休闲车，其底盘的参数变换也是利用了双曲线齿轮这一特性。由于有这些优点，目前汽车的驱动桥已经趋向于用双曲线齿轮，实际上近年进口汽车基本上是采用双曲线齿轮，国产汽车也有许多车型采用双曲线齿轮，并已经越来越多地在中、重型货车上得到采用。但双曲线齿轮工作时，齿面间会有较大的相对滑动，且齿面压力很大，齿面油膜容易被破坏。为减少摩擦，提高效率，必须要采用含有防刮伤添加剂的专用双曲线齿轮油，绝不能用其它的齿轮油代替，否则将使齿面迅速磨损和擦伤，严重影响汽车的运行状态。
展开阅读全文