What does the pitch circle represent?

The pitch circle represents the theoretical circle on which the teeth of a pulley or gear effectively engage with the belt or chain. It is critical in the design and operation of mechanical systems involving gears, pulleys, and belts because it determines the proper meshing and friction between components. The length of the belt at the location of tension members is indeed determined by this pitch circle, as it directly relates to how tight or loose the belt is around the pulleys or gears. For effective power transmission and to reduce wear, it's essential that the belt runs along this pitch circle. Understanding the pitch circle is key for ensuring efficient operation of the drive system and maintaining proper alignment of the components.