Gears
Gears are an essential part of virtually every mechanical device. We see gears in almost everything that has moving or spinning parts. Basically, gears are wheels with teeth cut into the circumference so they can turn each other without slippage. Essentially, gears operate under the same principal as levers. The teeth on gears act as spinning levers that push each other to produce relative motion. Gears are generally used for one of for main reasons:- To increase or decrease the speed or force of applied motion. - To move rotational motion to a different axis. - To keep the rotation of multiple axes synchronized. There are several types of gears commonly used. Spur gears are used when the shafts must rotate on the same plane, or parallel to each other. The teeth on these gears are straight and parallel to the shaft. Helical gears are spur gears with the teeth cut on an angle, which allows the teeth to engage smoother, and quieter. As well, more teeth can engage at an given time dispersing the load of the work done more evenly over the gear. Beveled gears have teeth that are sloped along one surface of the gear, allowing two gears to engage each other at angles so the rotational
A gear train consists of large and small gears paired together on individual axes, with the large gear of one pair meshing with the smaller gear of the next pair. As the larger gear rotates, its smaller partner rotates at the same speed. This small gear meshes with the largest of the next pair creating a low speed, high power ratio. With this setup, very high or low gear ratios are possible. However, achieving such ratios require a large number of gears, axels, and space. With more parts to move, friction is greatly increased, as well as the weight of many gears and axels. In order to create high gear ratios without sacrificing space or loosing efficiency to friction, a worm gear is used. This is a very small, but efficient setup where the planes of motion are perpendicular to each other. If a parallel plane of motion is desired, a worm gear engages a helical gear, where the teeth and threads are cut at equal angles. Electric motors operate at extremely high speeds. Some small, inexpensive motors for hobby purposes can exceed speeds of 30,000 rpm. These speeds are very impractical for almost any application, as torque decrease with increase in speed. With the application of gears, and gears trains, high gear ratios can be produced, lowering speeds and greatly increasing power output. Gears are used everywhere in m
Some common words found in the essay are:
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Approximate Word count = 901
Approximate Pages = 4 (250 words per page double spaced)
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