A differential is a group of gears that lead the wheels to drive at diverse speeds when the vehicle is going around the corners. In other words, a differential makes the wheels spin at two different speeds. The differential does this using a set of gearwheels. In this article, we discuss different types of differentials used.
What actually happens is that, if one of the wheels slows down in spin while the vehicle is taking a turn, the wheel spin is replaced by a turn force that exerts itself on the slower spinning wheel. Thus it does not affect the rotation of the main gear wheels in the differential, allowing them to spin in the same speed, despite itself getting slowed down.
When we think of wheels spinning in different speeds, there is an important distinction that has to be made. That is, the difference between driving and driven wheels (free wheels that are not attached to the drive-shaft). When the vehicle is taking a turn, there is still difference between two driven wheels, but there is no drag on the ground, because they are free. But in case of driving wheels, without a differential, both the wheels will be rotated with the same speed and they would experience drag.
Front engine, Front-wheel drive:
In a front engine, front-wheel drive or a rear engine, rear-wheel drive, there is no need of a driving column that runs through the floor of the vehicle. The differentials directly receive rotational input from the engine and transfer it to the wheels.
Front engine, Back wheel drive:
In this case, the differential receives rotation from the drive shaft which connects the engine to the rear.
Four wheel drives:
In a two wheel drive system, only two wheels are powered, and the other two are free and driven. This means that torque generated by the engine is received only by two wheels. So, to increase the torque, the other two wheels have to be powered also. When all the four wheels of a vehicle is powered, it is called a four-wheel drive There are two kinds of four-wheel drive systems, the 4WD and
The All-wheel drive.
The two kinds of four-wheel drives arise out of two technical possibilities. 1) All the four wheels are powered, that is, power is distributed to all the wheels, 2) All four wheels are powered with a differential between them, that is, the rear axle is made able to rotate at speeds without any regard to the front axle or vice-versa while making a turn, or while driving in a complex terrain.
But in addition to the benefits, a lot of other complications arise when extra differentials are introduced. Usually these are met with the addition of supportive mechanisms.