| Gears are everywhere, often hidden amongst the | | | | Other types of gears have been developed to serve |
| inner workings of highly advanced machinery or simple | | | | particular purposes. Helical gears employ a more |
| items whose use and operation we take for granted. | | | | gradual engagement of the teeth, which creates a |
| A gear is a component that transmits force from a | | | | smoother operation. Bevel gears are most useful for |
| power source to a device. In a very simple design the | | | | changing the direction of a shafts rotation. Hypoid |
| power source turns the gear, which links to another | | | | gears are used in order to change the axes on which |
| gear or to a device through teeth, or "cogs", that mesh | | | | the opposing shafts operate. Worm gears are |
| together, thereby transferring the power of the original | | | | extremely efficient in creating large gear reductions. |
| source onward. | | | | The versatility of gears is nearly unlimited. Gears can |
| A well-known example of a gear in action would be a | | | | be used to coordinate multiple shafts to run at equal |
| water wheel on a mill. The energy source in this | | | | speeds in the same or opposite directions or to run at |
| instance is the water, which turns the gear (the water | | | | varying speeds. Gear sizes can be manipulated to |
| wheel), the water wheel has a shaft transferring that | | | | create high torque, or high speeds, beyond the direct |
| energy to another gear, on the opposite end, meshed | | | | power of the original energy source. |
| to a second gear which drives the mill stone. | | | | The use of gears can be seen in a variety of |
| The most advantageous feature of the gear is that | | | | applications. Gears, of course, are used to convert the |
| gears of unequal sizes can be combined to produce | | | | power from a car motor to the torque and force used |
| increased or decreased speed or torque, as the | | | | to propel the vehicle. Rack and pinion gears are used |
| mechanical operation requires. This is what is known | | | | in the steering systems of vehicles. Gears are used to |
| as creating a mechanical advantage. This change in | | | | operate conveyor belts and to turn the rotors of |
| the power of the original source of energy is known | | | | helicopters and can be found in simple items like a |
| as the gear ratio and is determined by the change in | | | | household scale. |
| size from one gear to another. | | | | Based off of one of man's earliest technological |
| There are a number of different designs for gears. A | | | | achievements, the wheel, gears are now used to |
| spur gear is the most basic design. In this design the | | | | harness the energy of any number of power sources. |
| teeth of the connecting gears are straight and contact | | | | Continuous advances in the implementation and design |
| each other at the same time. While this can supply a | | | | of gears enable humankind to reach ever-higher levels |
| great deal of force and energy transfer, it tends to | | | | of achievement, simplify work and create all manner of |
| great very loud operations and high amounts of stress | | | | labor saving devices. |
| on the gears. | | | | |