Back-up rolls are generally used in tension levelers, levelers, rolling mills and other equipment. Since the work roll is relatively slender, it cannot bear the radial load generated when straightening the shape of the sheet and rolling the sheet. At this time, it is necessary to arrange a back-up roll under the work roll or the intermediate roll to bear the radial load, which acts as a pair of work rolls. , The role of the middle rollers is similar to lifting. If the circumference of the back-up roll is large and the concentricity is not good, it will directly affect the work roll, resulting in vibration lines and scratches on the plate shape after tension and straightening. Generally, the circular runout of the back-up roll should be controlled within 0.01mm. If the runout is too large, it is a non-standard product and should not be used.
Due to the use environment of the back-up roll, it must bear a large radial force, so it is the most critical mechanical part of the equipment except the work roll. Many equipment manufacturers do not understand the structure of the back-up rolls, and use ball bearings and bushing parts to assemble the back-up roll by themselves. This kind of back-up roll is extremely insufferable, and its poor accuracy affects the use.
The real back-up roll should be composed of mandrels, bearing sleeves, needle rollers, seals, fasteners, heat-resistant extreme pressure grease, and the heat treatment hardness, material selection, clearance fit, assembly and debugging of each part have specifications and requirements. . In the tension leveling line below 450m/min, the service cycle of the back-up roller should be between half a year and two years (depending on the initial plate type and use environment). If the back-up rolls is broken in two or three months, please Inform the supplier in time, it is basically a quality problem or improper use.