As an example, consider a person riding a bicycle, with the individual servo gearbox acting like the engine. If see your face tries to trip that bike up a steep hill in a gear that is designed for low rpm, he or she will struggle as
they try to maintain their balance and achieve an rpm that will allow them to climb the hill. However, if indeed they change the bike’s gears into a quickness that will produce a higher rpm, the rider will have
a much easier period of it. A constant force can be applied with even rotation being offered. The same logic applies for industrial applications that want lower speeds while preserving necessary
torque.
• Inertia coordinating. Today’s servo motors are producing more torque relative to frame size. That’s due to dense copper windings, lightweight materials, and high-energy magnets.
This creates greater inertial mismatches between servo motors and the loads they are trying to move. Utilizing a gearhead to better match the inertia of the electric motor to the inertia of the strain 
allows for utilizing a smaller electric motor and outcomes in a far more responsive system that’s simpler to tune. Again, this is attained through the gearhead’s ratio, where the reflected inertia of the strain to the electric motor is decreased by 1/ratio2.
Recall that inertia may be the measure of an object’s level of resistance to change in its movement and its own function of the object’s mass and shape. The greater an object’s inertia, the more torque is required to accelerate or decelerate the object. This implies that when the load inertia is much bigger than the engine inertia, sometimes it could cause excessive overshoot or boost settling times. Both conditions can decrease production line throughput.
However, when the engine inertia is larger than the load inertia, the engine will require more power than is otherwise necessary for this application. This raises costs since it requires paying more for a electric motor that’s bigger than necessary, and since the increased power intake requires higher working costs. The solution is to use a gearhead to match the inertia of the motor to the inertia of the load.