When we discuss the off-road performance of a car, we often hear the words "differential lock". If you are not interested in off-road, ordinary car owners may be relatively unfamiliar with this term. Even if some car owners know a little about it, it is easy to confuse the differential lock with the differential. So what is a differential lock and what? It's the differential again, let's talk about it today.

Differential main grasping speed difference

Before talking about the differential, let's look at an example.

In the school days, we started sports and walked into the field. Each class needs to walk around the playground runway in a square array. When the runway turns, the teacher usually emphasizes that the students on the outside of the queue need to walk in large strides, while the students on the inside need to walk slowly. Walk slowly or even stand still to ensure the integrity of the Founder. If the inside and outside students maintain their previous speed when turning a corner, the team will definitely disperse.

In fact, the vehicle is the same as the phalanx. When driving in a straight line, the four wheels rotate at the same speed to drive the vehicle forward. When encountering a curve, the speed of the inner and outer wheels must be different. What happens if the wheels spin at the same speed? The wheels on the left and right sides will inevitably interfere with each other, resulting in difficult turning and even accidents.

Because of this, engineers invented the differential. As the name implies, the differential is a device that exists to adjust the difference in speed between the left and right wheels.

With the differential, when the vehicle is traveling in a straight line, because the left and right wheels receive the same resistance, the planetary gear does not rotate, and the power is transmitted to the two half shafts. At this time, the left and right wheels rotate at the same speed (equivalent to a rigid connection); When the vehicle turns, the left and right wheels receive different resistance. The planetary gear rotates around the half shaft and rotates at the same time, so as to absorb the difference in resistance, so that the wheels can rotate at different speeds to ensure the smooth cornering of the vehicle.

Is everything going well with a differential? No, the differential still has a "BUG" for the hardcore SUV, that is, the faster the wheel speed (here can be understood as skidding), the more power it can obtain, and the side with the grip will be because of the lower speed. Unable to get power, as a result, he could not move, causing the car to get stuck.

In order to prevent the differential from messing up when necessary, engineers developed two things: a limited slip differential and a differential lock.

Differential lock special lock differential

As an upgrade of the ESP, the limited-slip differential increases the power of the wheel on the other side by applying a customized power to the slippery wheel. The differential lock is more extreme. It directly hard-connects the two half axles into one axle, so that the wheel on the side with the grip can obtain full power, thereby obtaining a strong ability to escape.

Not only four-wheel drive vehicles, even front-drive or rear-drive vehicles will also be equipped with a limited-slip differential that uses a multi-disc clutch to achieve more precise power distribution between the drive wheels on both sides and achieve more efficient power transmission, but it is more powerful In the extreme off-road environment, the limited slip differential will inevitably encounter the situation of overheating of the clutch plates, and because the hard connection of the half shafts on both sides cannot be realized, the passability is not strong.

For the hardcore SUV, the differential lock is indispensable for the four-wheel drive system to play the best role. Wheel skidding is common in off-roading, and even in extreme cases only one wheel has grip. If there is no differential lock, the power will be continuously output to the slippery wheels, resulting in wasted power. Therefore, hardcore SUVs are generally equipped with differential locks, which have become an important indicator of the performance of an off-road SUV.

Many hardcore SUVs now use differential locks and limited slip differentials together. The hardcore SUV is not only equipped with a central differential lock and a rear wheel differential lock on the four-wheel drive model, but also an electronic limited slip differential. In the absence of concerns about damaging the front axle, this hardcore SUV can also have a passing performance no weaker than three locks.

It is worth noting that the differential lock should be closed in time after the vehicle is out of trouble. Of course, many hardcore SUVs are now able to automatically detect the speed and turn off the differential lock. If the vehicle speed exceeds 30km/h (smart four-wheel drive) or 60km/h (time-sharing four-wheel drive), the vehicle will automatically close the differential lock to ensure safety.

In general, the differential is a necessary device to ensure the normal driving of the vehicle (especially when turning), and the differential lock is an off-road equipment that exists to allow the vehicle to better escape. For ordinary vehicles, it is not necessary to install a differential lock, but for a four-wheel drive hardcore SUV, the differential lock is too important. "The statement.