Rack Pinion Gears

Rack pinion gears are the most common type of gears. They have straight teeth, and are mounted on parallel shafts. Sometimes, many spur gears are used at once to create very large gear reductions.
gears are a very useful simple machine. The most common situation is for a gear to mesh with another gear, but a gear can mesh with any device having compatible teeth, such as linear moving racks. A gear’s most important feature is that gears of unequal sizes ( diameters) can be combined to produce a mechanical advantage, so that the rotational speed and torque of the second gear are different from that of the first, in the context of a particular machine, the term “ gear” also refers to one particular arrangement of gears among other arrangements ( such as “first gear”). Such arrangements are often given as a ratio, using the number of teeth or gear diameter as units.