What does PL22 mean?
In many modern roller mills the rolls are driven by a poly-V (multi-rib) belt instead of gears. “PL” is the rib profile of the belt and “22” the number of ribs. The PL profile has a wide rib pitch and transmits high torque; the 22 ribs set the belt width and the power it can carry. Markings such as “PL-22-200” on a pulley give the profile, rib count and pulley diameter.
What makes the break set different
The break passage needs a high speed differential between the rolls. In a belt drive this differential comes from the diameter ratio of the pulleys. The PL22 break set combines pulleys chosen for the break-passage ratio, the taper bushes that fix them to the shafts and the tensioning parts that keep the belt at the right tension.
Why buy it as a set
- Pulley diameters match each other, removing the risk of a wrong ratio.
- Bush sizes and keyways complete the set; no extra machining is needed during fitting.
- All grooves are renewed at once, so a new belt carries load evenly and lasts longer.
When to replace
Polished groove flanks, belt marks on the groove bottom, the belt sinking into the grooves, more noise or vibration and frequent belt changes all indicate worn pulleys. Fitting a new belt on worn pulleys quickly ruins the belt.
Installation tips
Align the pulleys in the same plane so the belt does not rub on its sides. Tighten the taper bushes evenly with clean, oil-free tapered surfaces. Set belt tension with the tensioner and check it again after the first hours of running.
