Idler misalignment amplifies the effect of belt tension and is the major contributor of errors on Electro-Mechanical (E/M) belt weighing systems. Idlers alignment can only be as good as the idler sets to be aligned. Standard idlers vary from unit to unit in; troughing angle, T.I.R., idler deflection etc.
This makes accurate alignment almost impossible. Poor roller balance can also affect the scale performance.
To achieve the highest possible accuracy and most reliable operation one should use weigh class idlers on:
- The approach (before the weigh bridge).
- The weigh bridge.
- The retreat (after the weigh bridge).
- The Process Automation Accu-RollTM (in-line) weigh class idlers are purpose designed to match the application and scale model.
Each application is computer analysed to optimise:
- Idler roll diameter.
- Roll shaft diameter.
- Roll TIR.
- Roller dynamic balance.
- Idler base section.
- Deflections that can be accommodated.
- Stiffness for very high speed applications.
These idler bases are manufactured to the stringent troughing angle tolerances required for high precision weighing duty. On application with higher belt speeds (in excess of approx. 150m/min), the idler rolls are dynamically balanced additionally (steel rollers only).
The idler rolls are selected to meet the low break-away torque required for weighing duty.