Hello, Guys, Differential is a system that transfers power from the engine to the wheels. The differential is designed to rotate a pair of wheels at different speeds when required and distribute the torque to each wheel. Without Differential, the tire would skit in corners cause both wheels will rotate together and the outside tire travels faster than the inside. It is at the centre of the front and rear axle on 4X4.
Courtesy : ConceptVBS
Types of Differential
Open differential splits the torque to both wheels, which is then able to rotate at different speeds. It is not good for off-road vehicles, as they typically send all the power from the driveshaft to the wheel with the least amount of traction. They are widely used in most on-road cars because they are cheap.
The locked differential is mostly used on off-road vehicles where the torque needs to flow on both wheels giving higher traction. This helps both the wheels to spin together at equal speed regardless of which axle has traction or is losing traction.
There are two ways to use the Locking differential, Automatic and Selectable locking differential. Automatic is less expensive and it does not require the driver to do anything. The differential locks when there is a substantial torque and unlocks when the torque load is light. The locking and unlocking are quite loud.
Selectable Differential is a better option than automatic differential. They are quite expensive. The selection of differential can be done using a switch that controls an electrical or hydraulic system that locks the differential. When you lock the differential it is good for off-road and when unlocked good for on-road.
It is the combination of open and locked differential. In the straight, the power is sent to both wheels. It works as an open differential under most circumstances but locks itself when a slip occurs and sends the power to the wheel which has more traction. Lock-up can be achieved using a viscous fluid, clutch pack, gears. Electronically controlled LSD controls the wheel spin by controlling the brakes on that wheel.
4 Torque Vectoring
Torque vectoring is a bit complicated differential system, it has additional gear trains to overdrive the half shafts. It fine-tunes the torque sent to the wheels, which allows you to control the torque sent to the wheels.
This system could have 3 torque-vectoring differentials in the centre, front and back or an open differential at the centre and torque vectoring differential in front and back. It improves the handling of the car by controlling the torque sent to the wheels. It is a costly system and complicated also.
So the differential usage is depended on the type of road your driving and the vehicle.
- Open Differential good for on-road
- Limited Differential is good for paved surface and good for less aggressive off-road
- And Locked Differential is best for off-road surface