??????Many front and rear axles of heavy-duty vehicles have become further to increase the reduction ratio of the drive axle, and even add wheel-side reducers. In the United Kingdom, many bus front and rear axle assemblies use worm gear single-stage main reducers.
???????When the car is turning or driving on uneven roads, the left and right wheels of the front and rear axle assembly of the heavy-duty vehicle have unequal travel at the same time, so the speed should also be different. In addition, even if the car runs straight on a flat road, the left and right wheel strokes of the front and rear axle assemblies of the car are the same. Sometimes, due to differences in the manufacturing error of the outer diameter of the tire, the degree of tread wear, tire pressure or tire load, etc. The rolling radius causing them is not equal, resulting in different speeds.
Therefore, the front and rear axle assemblies of heavy-duty vehicles require the drive axle to transmit torque to the left and right drive wheels while enabling them to rotate at different angular speeds that meet the aforementioned kinematic requirements. This requirement is fulfilled by the differential. The simple symmetrical conical planetary gear differential, because of its simple structure and stable and reliable operation, has been widely used in various automobiles.
??????If the internal friction is not taken into account, the differential of the front and rear axle assembly of this heavy-duty vehicle distributes the torque equally to the left and right axles. Therefore, in a car equipped with this simple symmetrical conical planetary gear differential, when the adhesion coefficient of the left and right drive wheels and the road are different and one drive wheel slips and loses traction, the other attached heavy vehicle front and rear axles The drive wheels of the assembly will also lose traction.
??????In this case, the front and rear axles of heavy-duty vehicles always improve the passing ability of off-road vehicles. The differential lock can be used to lock the left and right half shafts together; or the cam type with high friction pair, worm gear type and with Self-locking differentials such as gears and free wheels of friction plates, so that the torque of the driving axle is transmitted to the non-slip driving wheels as much as possible, so as to make full use of the adhesion of the driving wheels to generate Sufficient traction to enable the car to continue driving.