Roll Removal And Load Cells
Roll Removal
All modern rolling mills have to be able to remove the rolls quickly, especially the work rolls. The work rolls wear and get damaged from time to time.
A shuttle table is used to remove the rolls. One set of rolls can be positioned on a shuttle table while another set is being removed. Once the rolls are removed from the mill and put onto the shuttle table, the shuttle table moves over and new rolls can be inserted into the rolling mill. This is accomplished with hydraulic cylinders and spindle clamps located on the rear of the rolling mill.
Before removing the rolls, spindle clamps located on the rear of the mill are used to clamp the universals or spindles accurately so when new rolls are put back in they line up perfectly with the spindles. Spindles can be spherical gear type enclosed in grease or they can be large, forged “U” type universals. Many older rolling mills have a four-leaf design, which make noise when the rolling mill is running, especially at low speeds.
Load Cells
Load cells are positioned between the hydraulic cylinder top chocks. Load cells not only tell the operator what the separating force is at each pass, but they can be automatically applied to control the hydraulic pressure accurately for skin pass rolling.
Above all, load cells allow for quick set up. Without strip going through the rolling mill, the rolls can be brought together and by simply pushing a button, the rolling mill is zeroed in. Load cells are also used to accurately control tension at any speed. Load cells are placed in passline roll housings. This system is more consistent than using torque at the tension reels.
