What is the function of differential gear box?

What is the function of differential gear box?

Option:

a. to allow drive wheels to run at different rpms
b. to maintain drive wheels to run at the same rpm to avoid skidding
c. to transmit torque from clutch to propeller shaft
d. none of the above

Correct Answer : a. to allow drive wheels to run at different rpms

Explanation:

The power is transmitted from engine to drive wheels. But while taking turn both the drive wheels do not require same power, for example, while taking right turn, the outer wheel require more power than inner wheel. Thus, to allow the drive wheels to run at different rpms while taking turn the differential gear box is used. This is a sun and planet type gear assembly. Apart from allowing the drive wheels to run at different rpms, the differential gear box is also used for the speed reduction while transmitting the torque. The speed of the propeller-shaft is far more and it has to be minimized before transmitting to the drive wheels.