Industrial Foley Types
It is a grooved rim that prevents the belt from coming out of its position. Such foleys are cheap, but they cannot hold the belt well at high temperatures and the belt may slip in place.
Foley Sencron
Fully synchronous gears have teeth in their environment and this makes the applied engine speed remain almost constant and less power is wasted. Synchronous or timing pulleys, as explained, have high efficiency in the system, and this characteristic of synchronous pulleys makes a narrower belt be used for them. Synchronous pulleys have more advantages than simple pulleys, for example, the belt slips at high temperatures in the system. with Foley synchronous reaches zero.
Round weeds
As can be deduced from their name, the only function of idler pulleys is to make the movements of the belts uniform in the system and keep them in their path.