The mechanical engineer is a scientist whose expertise is the application of the principles of physics in the designing, construction and function of mechanical systems (motion systems, transfer of power and others).
The main function of the mechanism is based on a complex system of toothed gears. In a pair of gears, the one that transmits the motion is called driver and the gear that receives the rotational motion is called driven gear. The more the teeth the slower the gear rotates and vice versa, the less the teeth the faster it rotates.
In a system of gears, the rotation ratio is defined by the following formula:
In an array of gears, we do not take into account the intermediate ones as to the speed and torque. However, the number of the gears affects the direction of movement. In an even number of gears, the motions of the first and of the last one are always counterbalanced.
The BIG gears are used for greater torque.
The SMALL gears are used for higher rotation speed.
In the game with the fan:
If you had to increase by means of gears the rotation speed of a fan, what would you do:
1) Use a speed system where the last gear would be SMALLER than the first one
2) Use a speed system where the last gear would be BIGGER than the first one