题目

英语翻译
In passenger cars,the final drive usually consists merely of a hypoid bevel-gear drive.The geometry of the bevel-drive pinion and of the crown wheel determines the final-drive ratio (i0=2.24~4.93 for standard-production vehicles) (Fig.3-18).The hypoid gear is in common use today due mainly to the fact that the offset pinion allows the propeller shaft to be set below (for cars),or above (for commercial vehicles) the crown wheel center.This gives either a reduction in the propeller shaft tunnel,which causes a bump in the vehicle floor,or in the case of a commercial vehicle a reduction in the angle though which the universal joint has to operate.
In commercial vehicles,the necessary final-drive ratio can only rarely be accommodated in one stage (bevel-gear drive).For this reason,use is usually made of more elaborate final-drive systems:
1) single-reduction axle (up to i0=7) ,
2) transmission-type axle with front-or top-mounted bevel-gear drive,
3) double-reduction

提问时间：2020-07-26

答案

在乘用车,最后驱动器通常由只是一个双曲线锥齿轮传动.该锥驱动齿轮及冠轮的几何形状决定的最终传动比（i0 = 2.24～标准生产汽车4.93）（图3-18）.准双曲面齿轮的普遍使用,主要是由于今天的事实,抵消小齿轮轴螺旋桨允许设置如下（汽车）,或以上（商用车辆）的冠轮中心.这使得无论是在螺旋桨轴隧,这将导致在车辆地板上撞,或在商业车辆而言,虽然在该角度万向节已减少了操作减少.
在商业车辆,必要的最终传动比只能很少能容纳一个阶段（伞齿轮驱动器）.出于这个原因,通常由使用更精细的最终驱动系统：
1）单减桥（最高至I0 = 7）,
2）传输型轴与前端或顶部安装的伞齿轮传动,
3）双减桥（总传动比达至I0 = 9）,
4）小齿轮轴（轮毂中直齿轮传动）,
5）行星减速桥枢纽（在特殊情况下也可移位）.
大冠车轮下的差别减少离地间隙.在小齿轮轴与行星集线器减少车桥,差速器和半轴较小的情况下,可通过把减少.这使得即使在高功率输出的情况下,实现对车辆有足够的离地间.
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