Here's how it works:
1. Power Input: The engine's power is transmitted to the differential through the transmission and driveshaft.
2. Differential Case: The differential sits within a case that houses the gears. The driveshaft connects to the input pinion gear within this case.
3. Side Gears (Planet Gears): The pinion gear meshes with a pair of side gears (also called bevel gears or planet gears) connected to each of the front wheels. These gears are able to rotate independently.
4. Rotating at Different Speeds: When the car goes straight, both front wheels rotate at the same speed. The pinion gear spins, driving both side gears equally.
5. Cornering: When cornering, the outer wheel needs to rotate faster than the inner wheel to cover a greater distance. The differential allows this to happen. The side gear connected to the outer wheel spins faster, while the inner wheel's side gear spins slower. This difference in rotational speed is smoothly accommodated by the differential's internal mechanism.
6. Torque Distribution: The differential typically splits the torque equally between the two wheels under normal conditions. However, this can lead to issues with traction. If one wheel loses traction (e.g., on ice or mud), all the power can go to that spinning wheel instead of the wheel with traction. This is why some FWD cars incorporate systems like traction control to mitigate this issue.
In short, the differential in an FWD car acts as a gearbox that allows independent wheel speeds, crucial for smooth cornering while efficiently distributing the engine's power to the front wheels. It's important to note that its design is fundamentally the same as the differentials used in rear-wheel-drive (RWD) vehicles, the only difference is which axle it's attached to.
