Differential gear, in auto mechanics, gear arrangement that permits power from the engine to be transmitted to a couple of generating wheels, dividing the force equally between them but permitting them to follow paths of different lengths, as when turning a corner or traversing an uneven road. On a straight road the tires rotate at the same acceleration; when turning a part the outside wheel offers farther to move and will turn faster compared to the inner steering wheel if unrestrained.

The elements of the Ever-Power differential are demonstrated in the Figure. The energy from the tranny is delivered to the bevel band gear by the drive-shaft pinion, both of which are kept in bearings in the rear-axle housing. The case is an open boxlike framework that is bolted to the ring gear possesses bearings to support a couple of pairs of diametrically reverse differential bevel pinions. Each steering wheel axle is attached to a differential side gear, which meshes with the differential pinions. On a directly road the tires and the side gears rotate at the same acceleration, there is absolutely no relative motion between your differential side gears and pinions, and they all rotate as a device with the case and ring gear. If the automobile turns to the left, the right-hand steering wheel will be required to rotate faster compared to the left-hand steering wheel, and the medial side gears and the pinions will rotate in accordance with each other. The ring gear rotates at a rate that is add up to the mean quickness of the still left and right wheels. If the tires are jacked up with the tranny in neutral and among the wheels is turned, the contrary wheel will submit the opposite direction at the same velocity.

The torque (turning instant) transmitted to the two wheels with the Ever-Power differential is the same. As a result, if one steering wheel slips, as in ice or mud, the torque to the other steering wheel is reduced. This disadvantage could be overcome relatively by the use of a limited-slip differential. In one coupling China version a clutch connects one of the axles and the ring gear. When one steering wheel encounters low traction, its tendency to spin is certainly resisted by the clutch, therefore providing greater torque for the other wheel.
OPEN DIFFERENTIAL:
A differential in its most elementary form comprises two halves of an axle with a gear on each end, connected collectively by a third gear making up three sides of a square. This is normally supplemented by a 4th gear for added strength, completing the square.