How does a triple set work?
On belt-driven roller mills the rolls are usually driven by a three-pulley layout: one is the motor or main drive pulley, the other two are the fast and slow roll pulleys. The belt wraps around all three; where a double-sided belt is used, one face drives one roll and the other face drives the other. The two rolls therefore run on a single belt in opposite directions and at different speeds.
Why a separate set for the break passage?
On the break passage, fluted rolls need a high speed differential to cut the kernel. The pulley diameters in the PL22 break triple set are chosen to give this high ratio. If it is confused with the smooth set, the break roll crushes the kernel, flour stays in the bran and extraction drops.
Advantages over a gear drive
- Quieter running and less vibration,
- A clean drive that needs no lubrication, so there is no flour-and-oil paste,
- The belt flexes slightly under shock loads, protecting the roll bearings.
Maintenance points
In a three-pulley system the critical points are alignment and tension. If one pulley is out of plane, the belt wears on its edge. Too little tension makes the belt slip, especially under the high break-passage load; too much strains the bearings. When changing the belt, check the grooves: polished grooves, or grooves where the belt bottoms out, mean the new belt will also fail early.
Ordering
Just tell us the mill model and that the set is for a break passage. The pulleys come with taper bush seats; we can send bushes for your shaft size with them.
