Thread Content
As an important component of roller conveyors, the rollers, once damaged, can cause the entire operation process to come to a halt, resulting in significant losses for production. Their replacement takes a long time (usually 3–5 hours), and the costs associated with repair and replacement are also relatively high. Shaft runout in the drum is a type of drum damage that can be predicted in advance; the main causes for this include: (1) the drum retaining sleeve not being properly secured. The reasons include bearing quality issues ； The roller shaft at the retaining sleeve area is ground smooth ； After the lock nut of the retaining sleeve is secured in place, there are three issues: the position of the stop washer does not align with the opening of the retaining sleeve, etc. Before repairing the drum, it is necessary to check the bearing clearance and determine the tightness of the lock nut. During the repair process, it is common to encounter a situation where the bearing clearance is too large at one opening, while when the lock nut is moved to the next opening, the bearing clearance becomes too small. The bearing has excessive play, the tightening amount is insufficient, and the drum is prone to shaft shifting ； With a small bearing clearance, the bearings are prone to getting stuck during the operation of the drum, leading to bearing damage. (2) The tensioning bolts of the drum hub are lost or broken. The phenomenon is that there is a large difference in the distance between the inner end faces of the two bearings and the ends of the drum, the bearing housings are hot, and abnormal noises are present. The reason is that when the hub tensioning bolts become loose, the other bolts lose their grip or crack due to uneven stress distribution. For the above two types of shaft misalignment issues, the solutions are: (1) strengthen the procurement and management of spare parts such as drum bearings and retaining rings to ensure their quality. Due to the different manufacturers of the products, there are slight variations in the bearing clearance. Based on the usage status of spare parts from various manufacturers, the repair technicians determined that certain products were suitable for use, thereby ensuring the quality of spare parts for roller repairs. (2) Based on the actual conditions, spraying or hot-inserting shaft sleeves was employed to address the potential for shaft shift in the drum caused by worn shafts. (3) To prevent the situation where, after the locking nut of the retaining sleeve is secured in place during roller repair, the position of the stop gasket does not align with the opening of the retaining sleeve, two openings were machined in the bushing at appropriate positions. After two openings are created, the lock nut allows an opening to secure the locking block every 20° of rotation. (4) To reduce the likelihood of shaft shifting in the drum, shaft stop sleeves are installed on both sides of the drum shaft. (5) Strengthen the routine inspection by opening the cover at the drum hub area; after repairing other parts of the drum, it is essential to check that the hub tensioning bolts are properly tightened to ensure that the repaired drum does not suffer from shaft shifting. After the implementation of the above methods, the on-site service life of the rollers in roller conveyors has been significantly extended, effectively preventing economic losses caused by shaft misalignment of the rollers.