ABSTRACT
There are many types of gears , each designed according to its special application. The most common types are as follows :
Spur gear (Figure 20 . 1 ) . This is the simplest and most common form of all gear types. In this type, the teeth are cut straight and parallel to the axis of the shaft, and motion is transmitted from one parallel shaft to another. Spur gears are very widely used in machine construction because of their simplicity and economy. However, their use is limited to low to moderate speeds because of their low contact ratios.
