07-10-2017, 11:59 AM
The simple gear train is used where there is a great distance to be covered between the input shaft and the output shaft. Each gear in a simple gear train is mounted on its own shaft. When examining simple gear trains, it is necessary to decide whether the output gear will rotate faster, slower or the same speed as the input gear. The circumference (distance around the outer edge) of these two gears will determine their relative speeds.
Assume that the circumference of the input gear is greater than the circumference of the output gear. The output gear will rotate faster than the input gear. On the other hand, the circumference of the input gear could be less than the circumference of the output gear. In this case, the output gear would rotate more slowly than the input gear. If the input and output gears are exactly the same size, they will rotate at the same speed. In many simple gear trains there are several gears between the input gear and the output gear. These medium gears are called crazy gears. Idle gears do not affect the speed of the output gear.
Assume that the circumference of the input gear is greater than the circumference of the output gear. The output gear will rotate faster than the input gear. On the other hand, the circumference of the input gear could be less than the circumference of the output gear. In this case, the output gear would rotate more slowly than the input gear. If the input and output gears are exactly the same size, they will rotate at the same speed. In many simple gear trains there are several gears between the input gear and the output gear. These medium gears are called crazy gears. Idle gears do not affect the speed of the output gear.