Differential

Differential  : When the vehicle travels around a corner, the distance traveled by the outer wheel is greater than that traveled by the inner wheel. If the wheels are mounted on dead axles so that they turn independently of each other, (the front wheels of the vehicle an ordinary vehicle) they turn at different speeds to compensate for the difference in travel. But the the wheels are positively driven by the engine to device is necessary to permit them to revolve at different speeds without interfering with the propulsion of the vehicle. To accomplish this purpose, a system of the differential gears is provided to allow the outer wheel to revolve at a higher speed than the inner wheel while turning corner. In this way, the inner wheel skidding of the which involves the sliding friction. being harmful for the life of the tyres is overcome

Construction and working :

Figure shows the construction and working of the differential mechanism.
It Consists of The Following components:
(i) Crown wheel or ring gear
(ii) Drive pinion or crown pinion.
(iii) Cage
(iv) Sun gears
(v) Planet or star pinions.
The drive pinion meshes with the crown wheel. The crown wheel is free to rotate on the rear axle half shafts whereas the sun gears are splined on the ends of each half shaft. The cage is rigidly attached to the crown wheel. The cage consists of the pin on which two planet pinions are mounted. The planet pinions are free to rotate on the pin but are meshed with the sun gears.

When the vehicle is traveling straight in the head position, the power flow from the drive pinion is shown in the Figure a. The drive pinion gives the power to the crown wheel whereas the crown wheel, cage, the pin and the planet pinions rotate the one unit. The planet pinions revolves on the pin but the axes their transmit the power to the sun gears. The sun gears and the half shafts are splined together and revolve due to the rotary motion of the planet gears to the whole .