Gears are found in tons of mechanical devices. They do a number of important jobs, but most important, they offer a gear reduction in motorized equipment. This is key because, frequently, a little motor spinning extremely fast can provide plenty of power for a device, but not enough torque. For instance, an electric screwdriver has a very large gear reduction since it needs lots of torque to carefully turn screws, bu­t the motor only produces a little amount of torque at a high speed. With a gear reduction, the output speed could be reduced while the torque is increased.

One more thing gears do is definitely change the direction of rotation. For instance, in the differential between your rear wheels of your car, the power is definitely transmitted by a shaft that operates down the center of the car, and the differential has to convert that power 90 degrees to apply it to the tires.

There are a lot of intricacies in the different types of gears. In this post, we’ll learn exactly how the tooth on gears work, and we’ll discuss the different type­s of gears you find in all sorts of mechanical Gearbox gadgets.­


On any equipment, the ratio is determined by the distances from the guts of the gear to the idea of contact. For example, in a gadget with two gears, if one gear is twice the diameter of the additional, the ratio will be 2:1.

Probably the most primitive types of gears we could look at would be a wheel with wooden pegs protruding of it.

The problem with this kind of gear is that the distance from the center of every gear to the point of contact changes as the gears rotate. This implies that the gear ratio adjustments as the gear turns, and therefore the output acceleration also changes. If you used a equipment like this in your car, it would be impossible to keep up a continuous speed — you would be accelerating and decelerating constantly.

Many modern gears use a particular tooth profile named an involute. This profile gets the very important property of maintaining a constant speed ratio between your two gears. Like the peg wheel above, the contact stage moves; but the shape of the involute gear tooth compensates because of this movement. Find this section for details.

Now let’s check out some of the different types of gears.