What is a pitch circle ?
The pitch circle is the reference circle for determining pitch, which is the distance between teeth.
The pitch (circular pitch) is obtained by dividing the length of the circumference of the pitch circle by the number of teeth.
The pitch circle is a virtual circle, and unlike the tip circle and the root circle, it cannot be seen by the eye.
The pitch circle is illustrated below.
相关链接 - 节圆