There are variety of gears available that are used in different industries according to the specific requirements. These gears can be classified under automotive gears, mining gears, marine gears, wind turbines, bicycle gears, mill heads, instrumentation gears, conveyor system and more.
The basic function of the gear is to alter the rotational speed, power or torque and direction between input and output shaft. Torque is the measure of force required to produce torsion and rotation about an axis. When a large gear drive is coupled with a smaller gear drive, the torque is reduced and the speed of the rotation is increased. Different arrangement of the gears can also be used for enhancement of positioning system.