Cylindrical gears are the most common type of manufactured gear. They are typically usedfor low and medium speeds because at high speeds, if they are not rectified, or corrected,they produce a variable noise.

These gears are called internal gears because the cut takes place on the inside part of a ringor a wheel. Their main characteristic is that the gaps between their teeth correspond tothose on an external cut. They are used mainly in planetary groups.

This type of gear allows the transmission of movement between axes that are separated.The mechanism consists of a closed chain whose links lubricate the fixed sprockets to theaxes of the conducting and conducted mechanisms.

Rack type gears are special because they are considered toothed wheels of infinitediameter. They are used to transform the circular movements of a gear into rectilinearmovement.

They consist of double helical gears amid a helix to the right and left with the teeth forming a V shape. Their aim is to eliminate axial forces and minimise slipping errors.

These types of gear form mechanisms along with worm gears and their aim is to transmithigh forces as well as to provide speed reductions that will increase the strength oftransmission.