> How Gears Work
  › Introduction
  › Basics
  › Helical Gears
  › Bevel Gears
  › Worm Gears

> What is a Gear Ratio?
> How to select a Gearbox?
> Thermal Limits of Gearboxes
> Synthetic Gear Oil Selection
> Controlling Gearbox Contamination
> Avoiding Gear Maintanance Errors
> Failure Analysis for Gearing

Introduction

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

Another thing gears do is adjust the direction of rotation. For instance, in the differential between the rear wheels of your car, the power is transmitted by a shaft that runs down the center of the car, and the differential has to turn that power 90 degrees to apply it to the wheels.

There are a lot of intricacies in the different types of gears. Read on to learn exactly how the teeth on gears work, see the different types of gears you find in various mechanical gadgets.