How Do Gears Work?

It’s not a very common thing to find someone who doesn’t know what a gear is. They’re everywhere in the world, on everything from bikes to buses, and have been for generations. Here we’ll take a closer look at exactly what a gear is, how it’s made, and how it works.

What is a Gear?

Gear is a simple wheel with toothed edges fixed in machines to enable different parts to move at a different speed or different directions. Gears transit rotary action from a moving shaft to another and also to change the direction of rotation.

How Do Gears Work?

Gears are used for transmitting power from one part of a machine to another. For example, in a bicycle take power from the pedals to the back wheel. Similarly, in a car, gears transmit power from the crankshaft (the rotating axle that takes power from the engine) to the driveshaft running under the car that ultimately powers the wheels.

There can be any number of gears connected together and they can be in different shapes and sizes. Each time you pass power from one gear wheel to another, one of the three things happen:

  • Increase Speed: If you connect two gears together and the first one has more teeth than the second one (generally that means it’s a bigger-sized wheel), the second one has to turn round much faster to keep up. So this arrangement means the second wheel turns faster than the first one but with less force. Looking at our diagram below, turning the red wheel (with 40 teeth) would make the blue wheel (with 20 teeth) go twice as fast but with half as much force.
  • Increase Force: If the second wheel in a pair of gears has more teeth than the first one (that is, if it’s a larger wheel), it turns slower than the first one but with more force.
  • Change Direction: When two gears mesh together, the second one always turns in the opposite direction. So if the first one turns clockwise, the second one must turn counterclockwise. You can also use specially shaped gears to make the power of a machine turn through an angle. In a car, for example, the differential (a gearbox in the middle of the rear axle of a rear-wheel drive car) uses a cone-shaped bevel gear to turn the driveshaft’s power through 90 degrees and turn the back wheels.
How Do Gears Work?

Types of Gears

There are various types of gears depending on their applications. But broadly these are divided into four types:

Spur Gears

It is used to transmit motion and power between two parallel shafts. Spur gears are used for a wide range of speed ratios in a variety of mechanical applications, such as clocks, electric screwdrivers, pumps, watering systems, material handling equipment, power plant machinery, and clothes washing and drying machines.

How Do Gears Work
Spur Gear

Helical Gears

It is used to transmit motion and power between two parallel shafts. Crossed helical gears can be employed for non-parallel shafts (usually perpendicular); however, are rarely used. The most common use for helical gears is in automotive transmissions. Helical gears are ideal for high-speed applications because they suffer from less friction and wear than other gears, but they’re still capable of transferring significant amounts of force.

How Do Gears Work
Helical Gear

Bevel Gears

It is used to transmit motion and power between two intersecting shafts (not necessarily perpendicular). Bevel gears are used in differential drives, which can transmit power to two axles spinning at different speeds, such as those on a cornering automobile. Bevel gears are used as the main mechanism for a hand drill.

How Do Gears Work
Bevel Gear

Worm Gears

It is used to transmit motion and power between two non-intersecting shafts, which are usually perpendicular to each other. Worm gears are used in the manufacturing and packaging industries. They are used in packaging equipment, small machinery, and conveyors. They are ideal for these types of equipment because they have fewer gear sets which achieve high gear ratios.

How Do Gears Work
Worm Gear
Types of Monitors


We hope that you have enjoyed this blog about how do gears work. It is a useful article that we have put together as we get many inquiries gears. If you have any questions about gears, please leave us a comment in the comment section below, we will be happy to help you out! Thank you for reading our article.

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Image Credit: Gearbox photo created by onlyyouqj –

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