# Truck differential introduction

Update:06-06-2018
Abst:

As we all know, when the car is turning, the ou […]

As we all know, when the car is turning, the outer wheel is longer than the inner wheel; when the car is traveling straight on the uneven road, the length of the curve of the wheels on both sides is not equal; even if the road is very straight, due to the tire Manufacturing dimensional error, different degree of wear, different load or inflation pressure, the rolling radius of each tire can not be equal. If the wheels on both sides are fixed on the same rigid shaft, the angular speed of the two wheels is equal, then the wheel must appear. The phenomenon of sliding while rolling.

The sliding of the wheel on the road surface not only accelerates tire wear, increases the power consumption of the car, but also may cause deterioration in steering and braking performance. If the driven gear of the final drive gear drives the drive wheels on both sides through a single 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 pure rolling state, it is necessary to use two half shafts to connect the two wheels respectively, and the driven gear of the final drive drives the two side axles and the wheels through the differential respectively, so that they can be used differently. The angular velocity is rotated. The differential between the drive wheels on either side of the same transaxle is called the inter-wheel differential.。

The general differential is mainly composed of planetary gears, planetary gear carriers (differential shells), half shaft gears, etc. The power of the engine enters the differential through the transmission shaft, directly drives the differential case, and then the left by the planetary wheels. The right two half shafts drive the left and right wheels respectively. When the vehicle goes straight, the left and right wheels are subjected to the same resistance, and the planetary gears in the differential case only revolve around the casing and do not rotate.
When the vehicle turns, the inner wheel will generate more resistance. The different forces on the two side axles will cause the middle planetary gear to rotate, and the two side axles will have a difference in rotation speed. The outside is faster than the inner wheel, so the vehicle can make a smooth turn.

When the differential travels in a straight line, the resistance of the left and right drive wheels is approximately the same. The power output from the engine is first transmitted to the differential housing to cause the differential housing to begin to rotate. Next, we must transfer the power from the shell to the left and right axles. We can understand that the two side gears are “competitive” with each other. Since the resistance of the two wheels is the same, neither of them can slap each other, so the differential shell The planetary gears in the body revolve around the casing without rotating, and the two planetary gears mesh with the two half-shaft gears at the same speed, so that the car can travel straight!

Assuming that the vehicle is now turning to the left, the distance traveled by the left drive wheel is relatively short, which will result in greater resistance. The differential housing is connected to the output shaft through the gear. The rotation speed of the differential housing does not change when the rotation speed of the transmission shaft is constant, so the left side shaft gear will rotate slower than the differential housing. It is equivalent to the planetary gear to drive the left half shaft more laboriously. At this time, the planetary gear will generate autobiography, and more torque will be transmitted to the right side gear. Due to the revolution of the planetary gear plus its own autobiography, the right half will be caused. The shaft gear will increase in speed based on the speed of the differential housing, so that the right wheel rotates faster than the left wheel, thus enabling the vehicle to achieve a smooth turn.