As we all know, when a car is turning, the outer wheel travels longer than the inner wheel; when the car is driving straight on uneven roads, the length of the curve traveled by the wheels on both sides is not equal; even if the road is very straight, due to the tires Manufacturing dimensional errors, different degrees of wear, different loads or different inflation pressures, the rolling radii of each tire cannot actually be equal. If both wheels are fixed on the same rigid shaft and the angular velocity of the two wheels is equal, the wheels will inevitably appear The phenomenon of sliding while rolling.

The sliding of the wheels on the road will not only accelerate tire wear and increase the power consumption of the car, but also may cause deterioration of steering and braking performance. If the driven gear of the main reducer simultaneously drives the driving wheels on both sides through a whole shaft, the wheels on both sides can only rotate at the same speed. In order to ensure that the driving wheels on both sides are in a pure rolling state, it is necessary to use two half shafts to connect the wheels on both sides respectively, and the driven gear of the main reducer drives the half shafts and wheels on both sides through the differential, so that they can be used differently. Angular velocity rotation. This type of differential installed between the driving wheels on both sides of the same drive axle is called an inter-wheel differential.

Generally, the differential is mainly composed of planetary gears, planetary gear carriers (differential housing), half-shaft gears and other parts. The power of the engine enters the differential through the transmission shaft, directly drives the differential housing, and then is driven by the planetary wheel to the left. Two half shafts on the right and left, respectively driving the left and right wheels. When the vehicle is traveling straight, the resistance on the left and right wheels is equal, and the planetary gears in the differential housing only revolve with the housing and will not rotate.
When the vehicle turns, the inner wheel will produce greater resistance. The different forces on the two half shafts will cause the planetary gears in the middle to rotate, and there will be a difference in speed between the two half shafts. The outer wheels turn faster than the inner wheels so that the vehicle can turn smoothly.

The characteristic of the differential when traveling in a straight line is that the resistance of the left and right driving wheels is roughly the same. The power output from the engine is first transmitted to the differential housing to start the rotation of the differential housing. Next, we need to transfer the power from the housing to the left and right half shafts. We can understand that the half shaft gears on both sides "compete" with each other. Because the resistance of the wheels on both sides is the same, neither of them can break each other, so the differential case The planetary gears in the body revolve with the housing without rotating at the same time. The two planetary gears mesh with the two half-shaft gears to rotate at the same speed, so that the car can drive in a straight line!

Assuming that the vehicle is now turning to the left, the distance traveled by the left-hand drive wheel is relatively short, and relatively speaking, more resistance will be generated. The differential housing is connected to the output shaft by a gear. The speed of the differential housing does not change when the speed of the drive shaft does not change. Therefore, the left half shaft gear will rotate more slowly than the differential housing. It is equivalent to that the planetary gear drives the left half shaft more laboriously. At this time, the planetary gear will generate autobiography, which will transmit more torque to the right half shaft gear. Due to the revolution of the planetary gear plus its own autobiography, the right half shaft will be caused. The shaft gear will increase the speed on the basis of the speed of the differential housing, so that the right wheel will turn faster than the left wheel, so that the vehicle can achieve a smooth turn