The automobile differential is the main part of the dri […]
The automobile differential is the main part of the drive axle. Its function is to allow the two semi-axles to rotate at different speeds while transmitting power to the two semi-axles, so that the wheels on both sides can run at unequal distances in the form of pure rolling as much as possible, reducing the friction between the tires and the ground.
This adjustment of the differential is automatic, which involves the "minimum energy consumption principle", that is, all objects on the earth tend to consume the least energy. For example, if you put a bean in a bowl, the bean will automatically stay at the bottom of the bowl and never on the wall of the bowl, because the bottom of the bowl is the position with the lowest energy (potential energy), and it automatically chooses to be static (minimum kinetic energy) instead of Will keep moving. In the same way, the wheels will automatically tend to the lowest energy consumption state when turning, and automatically adjust the speed of the left and right wheels according to the turning radius.
When turning, due to the slipping phenomenon of the outer wheel and the slipping phenomenon of the inner wheel, the two driving wheels will produce two additional forces in opposite directions at this time. Due to the "minimum energy consumption principle", it will inevitably lead to the wheels on both sides. The rotation speeds are different, which destroys the balance of the three, and is reflected on the half shaft gears through the half shafts, forcing the planetary gears to rotate, so that the outer half shaft speed is accelerated, and the inner half shaft speed is slowed down, thereby realizing the speed of the wheels on both sides. difference.
If the drive wheels on both sides of the drive axle are rigidly connected by a single shaft, the two wheels can only rotate at the same angle. In this way, when the car turns, because the outer wheels move more than the inner wheels, the outer wheels will have slip while rolling, and the inner wheels will slip while rolling. Even if the car is driving straight, it will cause wheel slippage due to uneven road surface or unequal tire rolling radius (tire manufacturing error, different wear, uneven load or unequal air pressure) although the road is straight.
Sliding wheels will not only aggravate tire wear, increase power and fuel consumption, but also make it difficult to turn the car and worsen braking performance. In order to prevent the wheels from sliding as much as possible, the structure must ensure that the wheels can rotate at different angles.
Inter-axle differential: usually the driven wheel is supported on the main shaft with bearings to enable it to rotate at any angle, while the driving wheel is rigidly connected to two half shafts, and a differential is installed between the two half shafts. This kind of differential is also called an inter-axle differential.