Final Drive

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1. INTRODUCTION:-

• In a vehicle two half axle shafts rotate the driving wheel. These axle shafts are
located at 90° to the longitudinal centre line of an automobile vehicle.

• When power transmission is affected by a propeller shaft from the front to
rear, the half axle shaft are at 90° to the propeller shaft. So for transmitting the
power at 90° a pair of gears is used. This pair of gear is known as final drive.

• The final drive consists of a bevel pinion and a crown wheel or worm and wheel
arrangement. The bevel pinion is connected to a propeller shaft through a universal
joint. From the crown wheel the drive goes to differential.


2. NECESSITY OF FINAL DRIVE:-

• In an automobile vehicle, if the propeller shaft is geared rigidly to both the driving
wheels, then both the wheels will be rotated at the same speed.

• When the vehicle is driven on straight road, there will be no any problem. But when
vehicle takes turn or on a bumpy road, the right and left side wheel of the vehicle
will have to cover different distance i.e. outer wheel must travel than the inner
wheel.

• When the propeller shaft drives the inner and outer wheels, at one of the driving
wheel will tends to slip on the road because of this tyre wear quickly caused wheel
skidding and wheel cannot controlled on turn.
 


Differential:-
3.2.1 Definition of Differential:-

Differential is defined as an arrangement of a gear that permit one shaft to drive two other shafts which transmit equal torque, although the three shafts may be rotated at unequal speeds.