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. That is key because, often, a small motor spinning very fast can provide plenty of power for a device, however, not enough torque. For instance, an electric screwdriver includes a large gear reduction since it needs lots of torque to turn screws, bu­t the engine only produces a little quantity of torque at a high speed. With a gear reduction, the output speed could be reduced as the torque is increased.

Another thing gears do is certainly adjust the direction of rotation. For Liquid-ring Vacuum Pump example, in the differential between your rear wheels of your car, the energy can be transmitted by a shaft that operates down the guts of the car, and the differential has to change that power 90 degrees to use it to the wheels.

There are a great number of intricacies in the different types of gears. In this post, we’ll learn exactly the way the teeth on gears function, and we’ll talk about the different type­s of gears you discover in all sorts of mechanical gadgets.­


On any gear, the ratio depends upon the distances from the center of the gear to the idea of contact. For example, in a device with two gears, if one equipment is twice the diameter of the other, the ratio will be 2:1.

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

The problem with this type 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 changes as the apparatus turns, and therefore the output velocity also changes. If you used a gear such as this in your car, it could be impossible to maintain a constant speed — you’d be accelerating and decelerating constantly.

Many contemporary gears use a special tooth profile named an involute. This profile gets the very important property of maintaining a continuous speed ratio between the two gears. Like the peg wheel above, the contact point moves; but the form of the involute equipment tooth compensates because of this movement. Find this section for information.

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