Gears, Chains, and Sprockets - VEX Robotics

Worm GearsWorm gears are used to transmit power between two shafts that are at right angles to each other. Theyare frequently used where a large speed reduction or large mechanical advantage is required in alimited space. It is not uncommon to achieve ratios of 300:1 or greater. Another property of worms isthat the assembly automatically locks in position when power is not applied. The worm can easily turnthe gear, but the gear cannot turn the worm due to the high friction. This property is useful in designswhere a braking or locking action is desired.Gear RatiosGear ratios work based on the physical principle of mechanical advantage. As you can see in thediagram below, when a small gear meshes with a larger gear, the torque applied onto the smaller gearis increased. This increase is based on the difference between the radius of each gear. You will noticethat in this example, there is a torque increase of (3x).10■Unit 6: Gears, Chains, and Sprockets