Gears are mostly used in various machines and industries. With
the moving wheel of science and technology the use of gears have become
more common in all the upcoming industries. They form an essential part
in running of machines and vehicles. There are a number of different
types of gears used in different industries depending upon their
properties and usage. They can be classified under automotive gears,
mining gears, wind turbines, bicycle gears, mill heads, instrumentation
gears, conveyor system, marine gears etc.
Gears are used for two basic purposes; increase or decrease of rotation
speed and increase or decrease of power or torque. Torque is a measure
of a force to produce torsion and rotation about an axis. To increase
speed and reduce torque a large drive gear is coupled to a smaller
driven gear. To reduce speed and increase torque a small Lego gear
turning a larger gear is used. They are also used for enhancement for
positioning systems.